U.S. patent application number 13/305349 was filed with the patent office on 2012-03-22 for methods of using macrocyclic agonists of the ghrelin receptor for treatment of gastrointestinal motility disorders.
Invention is credited to Graeme L. Fraser, Hamid R. Hoveyda, Mark L. Peterson.
Application Number | 20120071412 13/305349 |
Document ID | / |
Family ID | 39197442 |
Filed Date | 2012-03-22 |
United States Patent
Application |
20120071412 |
Kind Code |
A1 |
Fraser; Graeme L. ; et
al. |
March 22, 2012 |
METHODS OF USING MACROCYCLIC AGONISTS OF THE GHRELIN RECEPTOR FOR
TREATMENT OF GASTROINTESTINAL MOTILITY DISORDERS
Abstract
The present invention provides novel conformationally-defined
macrocyclic compounds that have been demonstrated to be selective
agonists of the ghrelin receptor (growth hormone secretagogue
receptor, GHS-R1a and subtypes, isoforms and variants thereof).
Such compounds are useful as medicaments for treatment and
prevention of a range of medical conditions characterized by
disturbed gastrointestinal motility including, but not limited to,
post-surgical gastroparesis and post-operative ileus in combination
with opioid-induced bowel dysfunction. These agents are effective
for multiple disorders at dose levels equivalent to those required
to treat a single disorder.
Inventors: |
Fraser; Graeme L.;
(Rixensart, BE) ; Hoveyda; Hamid R.; (Quebec,
CA) ; Peterson; Mark L.; (Sherbrooke, CA) |
Family ID: |
39197442 |
Appl. No.: |
13/305349 |
Filed: |
November 28, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11774185 |
Jul 6, 2007 |
8088733 |
|
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13305349 |
|
|
|
|
60818915 |
Jul 6, 2006 |
|
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Current U.S.
Class: |
514/13.2 ;
514/21.1 |
Current CPC
Class: |
A61P 29/00 20180101;
A61P 1/00 20180101; A61P 1/08 20180101; A61K 31/33 20130101; A61P
1/04 20180101 |
Class at
Publication: |
514/13.2 ;
514/21.1 |
International
Class: |
A61K 38/12 20060101
A61K038/12; A61P 1/08 20060101 A61P001/08; A61P 29/00 20060101
A61P029/00; A61P 1/00 20060101 A61P001/00; A61P 1/04 20060101
A61P001/04 |
Claims
1. A method of stimulating gastrointestinal motility comprising
administering to a subject suffering from at least two disorders
caused by gastrointestinal dysmotility an effective amount of a
compound having any of the following structures: ##STR00042## or a
pharmaceutically acceptable salt thereof.
2. The method of claim 1, wherein the compound is administered
orally.
3. The method of claim 1, wherein the compound is administered
parenterally.
4. The method of claim 1, wherein the compound is administered
intracranially.
5. The method of claim 1, wherein the subject is a mammal.
6. The method of claim 1, wherein the subject is a human.
7. The method of claim 1, wherein the compound is co-administered
with an additional agent useful for stimulating gastrointestinal
motility.
8. The method of claim 1, wherein the disorders caused by
gastrointestinal dysmotility are selected from the group consisting
of postoperative ileus, gastroparesis, idiopathic gastroparesis,
diabetic gastroparesis, post-surgical gastroparesis, gastric
stasis, opioid-induced bowel dysfunction, chronic intestinal
pseudo-obstruction, short bowel syndrome, emesis,
constipation-predominant irritable bowel syndrome (IBS), delayed
gastric emptying, gastroesophageal reflux disease (GERD), gastric
ulcers, and Crohn's disease.
9. The method of claim 1, wherein one of the disorders is
postoperative ileus.
10. The method of claim 1, wherein one of the disorders is gastric
statis.
11. The method of claim 1, wherein one of the disorders is diabetic
gastroparesis or post-surgical gastroparesis.
12. The method of claim 1, wherein the disorders are postoperative
ileus and opioid-induced bowel dysfunction.
13. The method of claim 1, wherein the disorders are post-surgical
gastroparesis and opioid-induced bowel dysfunction.
14. The method of claim 1, wherein at least two disorders occur
concurrently.
15. The method of claim 1, wherein at least two disorders occur
sequentially.
16. The method of claim 1, wherein a dose level of the compound
having the structure shown in claim 1 to treat the at least two
disorders is an equivalent dose level to that required to treat a
single disorder caused by gastrointestinal dysmotility.
17. The method of claim 1, wherein the dose level of the compound
having the structure shown in claim 1 is in a range of about
50-150% of a dose level required to treat a single disorder caused
by gastrointestinal dysmotility.
Description
RELATED APPLICATION INFORMATION
[0001] This application is a continuation application of U.S.
patent application Ser. No. 11/774,185, filed Jul. 6, 2007, which
claims the benefit under 35 U.S.C. .sctn.119(e) of U.S. Provisional
Patent Application Ser. No. 60/818,915, filed Jul. 6, 2006, the
disclosures of each are incorporated by reference herein in their
entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to novel
conformationally-defined macrocyclic compounds that bind to and/or
are functional modulators of the ghrelin (growth hormone
secretagogue) receptor including GHS-R1a and subtypes, isoforms
and/or variants thereof. These novel macrocyclic compounds are
useful as therapeutics for a range of disease indications. In
particular, these compounds are useful for treatment and prevention
of multiple gastrointestinal disorders, whether occurring
simultaneously or sequentially, including, but not limited to,
post-operative ileus, gastroparesis, including idiopathic, diabetic
and post-surgical gastroparesis, opioid bowel dysfunction, chronic
intestinal pseudo-obstruction, short bowel syndrome and functional
gastrointestinal disorders.
BACKGROUND OF THE INVENTION
[0003] The improved understanding of various physiological
regulatory pathways enabled through the research efforts in
genomics and proteomics has begun to impact the discovery of novel
pharmaceutical agents. In particular, the identification of key
receptors and their endogenous ligands has created new
opportunities for exploitation of these receptor/ligand pairs as
therapeutic targets. For example, ghrelin is a recently
characterized 28-amino acid peptide hormone isolated originally
from the stomach of rats with the orthologue subsequently
identified in humans. (Kojima, M.; Hosoda, H. et al. Nature 1999,
402, 656-660.) The existence of this peptide in a range of other
species suggests a conserved and important role in normal
physiological function. This peptide has been demonstrated to be
the endogenous ligand for a previously orphan G protein-coupled
receptor (GPCR), type 1 growth hormone secretatogue receptor
(hGHS-R1a) (Howard, A. D.; Feighner, S. D.; et al. A receptor in
pituitary and hypothalamus that functions in growth hormone
release. Science 1996, 273, 974-977.) found predominantly in the
brain (arcuate nucleus and ventromedial nucleus in the
hypothalamus, hippocampus and substantia nigra) and pituitary.
(U.S. Pat. No. 6,242,199; Intl. Pat. Appl. Nos. WO 97/21730 and WO
97/22004) hGHS-R1a has recently been reclassified as the ghrelin
receptor (GHRN) in recognition of its endogenous ligand (Davenport,
A. P.; et al. International Union of Pharmacology. LVI. Ghrelin
Receptor Nomenclature, Distribution, and Function. Pharmacol, Rev.
2005, 57, 541-546). The receptor has also been detected in other
areas of the central nervous system (CNS) and in peripheral
tissues, for instance adrenal and thyroid glands, heart, lung,
kidney, and skeletal muscles. This receptor was identified and
cloned prior to the isolation and characterization of the
endogenous peptide ligand and is distinct from other receptors
involved in the regulation of growth hormone (GH) secretion, in
particular, the growth hormone-releasing hormone (GHRH)
receptor.
[0004] A unique characteristic of both the rat and human peptides
is the presence of the n-octanoyl (Oct) moiety on Ser.sup.3.
However, the des-acyl form predominates in circulation, with
approximately 90% of the hormone in this form. This group is
derived from a post-translational modification and appears relevant
for bioactivity and possibly also for transport into the CNS.
(Banks, W. A.; Tschop, M.; Robinson, S. M.; Heiman, M. L. Extent
and direction of ghrelin transport across the blood-brain barrier
is determined by its unique primary structure. J. Pharmacol. Exp.
Ther. 2002, 302, 822-827.) In a GH-releasing assay, the
des-octanoyl form of the hormone was at least 100-fold less potent
than the parent peptide, although it has been suggested that the
des-acyl species may be responsible for some of the other
biological effects associated with ghrelin. This des-acyl form has
also been postulated to be primarily responsible for the
cardiovascular and cell proliferation effects attributed to
ghrelin, while the acylated form participates in maintenance of
energy balance and growth hormone release. (Baldanzi, G.;
Filighenddu, N.; Cutrupi, S.; et al. Ghrelin and des-acyl ghrelin
inhibit cell death in cardiomyocytes and endothelial cells through
ERK1/2 and PI-3 kinase/AKT. J. Cell Biol. 2002, 159, 1029-1037)
Similarly, des-Gln.sup.14-ghrelin and its octanoylated derivative
have been isolated as endogenous forms of the hormone arising from
alternative splicing of the ghrelin gene, but both are found to be
inactive in stimulating GH release in vivo. (Hosoda, H.; Kojima,
M.; Matsuo, H.; Kangawa, K. Purification and characterization of
rat des-Gln.sup.14-ghrelin, a second endogenous ligand for the
growth hormone secretagogue receptor. J. Biol. Chem. 2000, 275,
21995-22000.). Other minor forms of ghrelin produced by
post-translational processing have been observed in plasma,
although no specific activity has been attributed to them. (Hosoda,
H.; Kojima, M.; et al. Structural divergence of human ghrelin.
Identification of multiple ghrelin-derived molecules produced by
post-translational processing. J. Biol. Chem. 2003, 278,
64-70.)
[0005] Even prior to the isolation of this receptor and its
endogenous peptide ligand, a significant amount of research was
devoted to finding agents that can stimulate GH secretion. The
proper regulation of human GH has significance not only for proper
body growth, but also a range of other critical physiological
effects. GH and other GH-stimulating peptides, such as GHRH and
growth hormone releasing factor (GRF), as well as their derivatives
and analogues, are administered via injection. Therefore, to better
take advantage of these positive effects, attention was focused on
the development of orally active therapeutic agents that would
increase GH secretion, termed GH secretagogues (GHS). Additionally,
use of these agents was expected to be able to more closely mimic
the pulsatile physiological release of GH.
[0006] Beginning with the identification of the growth
hormone-releasing peptides (GHRP) in the late 1970's, (Bowers, C.
Y. Growth hormone-releasing peptides: physiology and clinical
applications. Curr. Opin. Endocrinol. Diabetes 2000, 7, 168-174;
Camanni, F.; Ghigo, E.; Arvat, E. Growth hormone-releasing peptides
and their analogs. Front. Neurosci. 1998, 19, 47-72; Locatelli, V.;
Torsello, A. Growth hormone secretagogues: focus on the growth
hormone-releasing peptides. Pharmacol. Res. 1997, 36, 415-423.) a
host of agents have been studied for their potential to act as GHS.
In addition to their stimulation of GH release and concomitant
positive effects in that regard, GHS were projected to have utility
in the treatment of a variety of other disorders, including wasting
conditions (cachexia) as seen in HIV patients and cancer-induced
anorexia, musculoskeletal frailty in the elderly, and growth
hormone deficient diseases. Many efforts over the past 25 years
have yielded a number of potent, orally available GHS. (Isidro, M.
L.; Cordido, F. Growth hormone secretagogues. Comb. Chem. High
Throughput Screen. 2006, 9, 178-180; Smith, R. G.; Sun, Y. X.;
Beatancourt, L.; Asnicar, M. Growth hormone secretagogues:
prospects and pitfalls. Best Pract. Res. Clin. Endocrinol. Metab.
2004, 18, 333-347; Fehrentz, J.-A.; Martinez, J.; Boeglin, D.;
Guerlavais, V.; Deghenghi, R. Growth hormone secretagogues: Past,
present and future. IDrugs 2002, 5, 804-814; Svensson, J. Exp.
Opin. Ther. Patents 2000, 10, 1071-1080; Nargund, R. P.; Patchett,
A. A.; et al. Peptidomimetic growth hormone secretagogues. Design
considerations and therapeutic potential. J. Med. Chem. 1998, 41,
3103-3127; Ghigo, E; Arvat, E.; Camanni, F. Orally active growth
hormone secretagogues: state of the art and clinical perspective.
Ann. Med. 1998, 30, 159-168; Smith, R. G.; Van der Ploeg, L. H. T.;
Howard, A. D.; Feighner, S. D.; et al. Peptidomimetic regulation of
growth hormone secretion. Endocr. Rev. 1997, 18, 621-645.) These
include small peptides, such as hexarelin (Zentaris) and ipamorelin
(Novo Nordisk), and adenosine analogues, as well as small molecules
such as capromorelin (Pfizer), L-252,564 (Merck), MK-0677 (Merck),
NN703 (tabimorelin, Novo Nordisk), G-7203 (Genentech), S-37435
(Kaken) and SM-130868 (Sumitomo), designed to be orally active for
the stimulation of growth hormone. However, clinical testing with
such agents have rendered disappointing results due to, among other
things, lack of efficacy over prolonged treatment or undesired side
effects, including irreversible inhibition of cytochrome P450
enzymes. (Zdravkovic M.; Olse, A. K.; Christiansen, T.; et al. Eur.
J. Clin. Pharmacol. 2003, 58, 683-688.) Therefore, there remains a
need for pharmacological agents that could effectively target the
ghrelin receptor for therapeutic action.
[0007] Despite its involvement in GH modulation, ghrelin is
primarily synthesized in the oxyntic gland of the stomach, although
it is also produced in lesser amounts in other organs, including
the kidney, pancreas and hypothalamus. (Kojima, M.; Hsoda, H.;
Kangawa, K. Purification and distribution of ghrelin: the natural
endogenous ligand for the growth hormone secretagogue receptor.
Horm. Res. 2001, 56 (Suppl. 1), 93-97; Ariyasu, H.; Takaya, K.;
Tagami, T.; et al. Stomach is a major source of circulating
ghrelin, and feeding state determines plasma ghrelin-like
immunoreactivity levels in humans. J. Clin. Endocrinol. Metab.
2001, 86, 4753-4758.) In addition to its role in stimulating GH
release, the hormone has a variety of other endocrine and
non-endocrine functions (Broglio, F.; Gottero, C.; Arvat, E.;
Ghigo, E. Endocrine and non-endocrine actions of ghrelin. Horm.
Res. 2003, 59, 109-117; Hosoda, H.; Kojima, M.; Kangawa, K.
Biological, physiological, and pharmacological aspects of ghrelin.
J. Pharmacol, Sci. 2006, 100, 398-410.) and has been shown to
interact with a number of other systems in playing a role in
maintaining proper energy balance. (Horvath, T. L.; Diano, S.;
Sotonyi, P.; Heiman, M.; Tschop, M. Ghrelin and the regulation of
energy balance--a hypothalamic perspective. Endocrinology 2001,
142, 4163-4169; Casanueva, F. F.; Dieguez, C. Ghrelin: the link
connecting growth with metabolism and energy homeostasis. Rev.
Endocrinol. Metab. Disord. 2002, 3, 325-338.) In particular,
ghrelin plays a role as an orexigenic signal in the control of
feeding, in which it acts to counteract the effects of leptin.
Indeed, it was the first gut peptide proven to have such orexigenic
properties. (Kojima, M.; Kangawa, K. Ghrelin, an orexigenic
signaling molecule from the gastrointestinal tract. Curr. Opin.
Pharmacology 2002, 2, 665-668.) The hormone also is implicated in
the hypothalamic regulation of the synthesis and secretion of a
number of other neuropeptides involved in appetite and feeding
behavior. Levels of ghrelin are elevated in response to fasting or
extended food restriction. (Nakazato, M.; Murakami, N.; Date, Y.;
Kojima, M.; et al. A role for ghrelin in the central regulation of
feeding. Nature 2001, 409, 194-198.) For example, subjects
suffering with anorexia or bulimia exhibit elevated ghrelin levels.
Circulating levels of the hormone have been found to rise before
meals and fall after meals. In addition, diet-induced weight loss
leads to increased ghrelin levels, although obese subjects who have
gastric bypass surgery do not likewise experience such an increase.
(Cummings, D. E.; Weigle, D. S.; Frayo, R. S.; et al. Plasma
ghrelin levels after diet-induced weight loss or gastric bypass
surgery. N. Engl. J. Med. 2002, 346, 1623-1630)
[0008] This intimate involvement of ghrelin in control of food
intake and appetite has made it an attractive target for obesity
research. (Spanswick, D.; Lee, K. Emerging antiobesity drugs. Exp.
Opin. Emerging Drugs 2003, 8, 217-237; Horvath, T. L.; Castaneda,
T.; Tang-Christensen, M.; Pagotto, U.; Tschop, M. H. Ghrelin as a
potential anti-obesity target. Curr. Pharm. Design 2003, 9,
1383-1395; Crowley, V. E. F.; Yeo, G. S. H.; O-Rahilly, S. Obesity
therapy: altering the energy intake-and-expenditure balance sheet.
Nat. Rev. Drug Disc. 2002, 1, 276-286.) Indeed, few other natural
substances have been demonstrated to be involved in the modulation
of both GH secretion and food intake.
[0009] An additional effect of ghrelin that has not to date been
exploited for therapeutic purposes is in modulating gastric
motility and gastric acid secretion. The prokinetic activity
appears to be independent of the GH-secretory action and is likely
mediated by the vagal-cholinergic muscarinic pathway. The dose
levels required are equivalent to those necessary for the hormone's
GH and appetite stimulation actions. It is noteworthy that, in
contrast to its inactivity for ghrelin's other actions, the
des-acyl and des-Gln.sup.14 peptides demonstrated promotion of GI
motility as well. (Chen, C.-Y.; Inui, A.; Asakawa, A.; Fujino, K.;
Kato, I.; Chen, C.-C.; Ueno, N.; Fujimiya, M. Des-acyl ghrelin acts
by CRF type 2 receptors to disrupt fasted stomach motility in
conscious rats. Gastroenterology 2005, 129, 8-25; Chen, C.-Y.;
Chao, Y.; Chang, F.-Y.; Chien, E. J.; Lee, S.-D.; Doong, M.-L.
Intracisternal des-acyl ghrelin inhibits food intake and
non-nutrient gastric emptying in conscious rats. Int. J. Mol. Med.
2005, 16, 695-699; Trudel, L.; Bouin, M.; Tomasetto, C.; Eberling,
P.; St-Pierre, S.; Bannon, P.; L'Heureux, M. C.; Poitras, P. Two
new peptides to improve post-operative gastric ileus in dog.
Peptides 2003, 24, 531-534; Trudel, L.; Tomasetto, C.; Rio, M. C.;
Bouin, M.; Plourde, V.; Eberling, P.; Poitras, P.
Ghrelin/motilin-related peptide is a potent prokinetic to reverse
gastric postoperative ileus in rats. Am. J. Physiol, 2002, 282,
G948-G952; Peeters, T. L. Central and peripheral mechanisms by
which ghrelin regulates gut motility. J. Physiol. Pharmacol. 2003,
54(Supp. 4), 95-103.)
[0010] Ghrelin also has been implicated in various aspects of
reproduction and neonatal development. (Arvat, E.; Gianotti, L.;
Giordano, R.; et al. Growth hormone-releasing hormone and growth
hormone secretagogue-receptor ligands. Focus on reproductive
system. Endocrine 2001, 14, 35-43.) Also of significance are the
cardiovascular effects of ghrelin, since the peptide is a powerful
vasodilator. As such, ghrelin agonists have potential for the
treatment of chronic heart failure. (Nagaya, N.; Kangawa, K.
Ghrelin, a novel growth hormone-releasing peptide, in the treatment
of chronic heart failure. Regul. Pept. 2003, 114, 71-77; Nagaya,
N.; Kangawa, K. Ghrelin improves left ventricular dysfunction and
cardiac cachexia in heart failure. Curr. Opin. Pharmacol. 2003, 3,
146-151; Bedendi, I.; Alloatti, G.; Marcantoni, A.; Malan, D.;
Catapano, F.; Ghe, C.; et al. Cardiac effects of ghrelin and its
endogenous derivatives des-octanoyl ghrelin and
des-Gln.sup.14-ghrelin. Eur. J. Pharmacol. 2003, 476, 87-95;
Isgaard, J.; Johansson, I. Ghrelin and GHS on cardiovascular
applications/functions. J. Endocrinol. Invest. 2005, 28, 838-842.)
Intl. Pat, Appl. Publ. WO 2004/014412 describes the use of ghrelin
agonists for the protection of cell death in myocardial cells and
as a cardioprotectant treatment for conditions leading to heart
failure.
[0011] WO 2005/097174 and WO 2006/045314 discuss the use of GHS,
ghrelin and other peptides or combinations thereof for the
treatment of cachexia and chronic obstructive pulmonary disease,
respectively. WO 2005/09726 reports on GHS for treatment of
diseases caused by C-reactive protein. WO 2006/045319 describes the
use of GHS in the treatment of renal and/or liver failure and
complications thereof. More generally, WO 2005/097173 suggests the
use of GHS for the treatment of ghrelin deficiency, including a
wide array of therapeutic indications. Lastly, evidence has been
obtained that ghrelin may have implications in anxiety and other
CNS disorders as well as the improvement of memory. (Carlini, V.
P., Monzon, M. E., Varas, M. M., Cragnolini, A. B., Schioth, H. B.,
Scimonelli, T. N., de Barioglio, S. R. Ghrelin increases
anxiety-like behavior and memory retention in rats. Biochem.
Biophys. Res. Commun. 2002, 299, 739-743; Diano, S. Farr, S. A.;
Benoit, S. C.; et al. Ghrelin controls hippocampal spine synapse
density and memory performance. Nat. Neuroscience 2006, 9,
381-388.)
[0012] The myriad effects of ghrelin in humans have suggested the
existence of subtypes for its receptor, although none have as yet
been identified. (Torsello, A.; Locatelli, Y.; Melis, M. R.; Succu,
S.; Spano, M. S.; Deghenghi, R.; Muller, E. E.; Argiolas, A.;
Torsello, A.; Locatelli, V.; et al. Differential orexigenic effects
of hexarelin and its analogs in the rat hypothalamus: indication
for multiple growth hormone secretagogue receptor subtypes.
Neuroendocrinology 2000, 72, 327-332.) However, a truncated,
inactive form of GHS-R1a, termed GHS-R1b, was isolated and
identified during the original characterization studies. Evidence
is mounting that additional receptor subtypes could be present in
different tissues to explain the diverse effects displayed by the
endogenous peptides and synthetic GHS. For instance, high affinity
binding sites for ghrelin and des-acyl ghrelin have also been found
in breast cancer cell lines, cardiomyocytes, and guinea pig heart
that are involved in mediating the antiproliferative,
cardioprotective and negative cardiac inotropic effects of these
peptides. Similarly, specific GHS binding sites besides GHS-R1a and
GHS-R1b have been found in prostate cancer cells. Further, ghrelin
and des-acyl ghrelin exert different effects on cell proliferation
in prostate carcinoma cell lines, (Cassoni, P.; Ghe, C.; Marrocco,
T.; et al. Expression of ghrelin and biological activity of
specific receptors for ghrelin and des-acyl ghrelin in human
prostate neoplasms and related cell lines. Eur. J. Endocrinol.
2004, 150, 173-184.) These various receptor subtypes may then be
implicated independently in the wide array of biological activities
displayed by the endogenous peptides and synthetic GHS. Indeed,
recently, the existence of receptor subtypes was offered as an
explanation for the promotion of fat accumulation by ghrelin,
despite its potent stimulation of the lipolytic hormone, growth
hormone. (Thompson, N. M.; Gill, D. A. S.; Davies, R.; Loveridge,
N.; Houston, P. A.; Robinson, I. C. A. F.; Wells, T. Ghrelin and
des-octanoyl ghrelin promote adipogenesis directly in vivo by a
mechanism independent of the type 1a growth hormone secretagogue
receptor. Endocrinology 2004, 145, 234-242.) Further, this work
suggested that the ratio of ghrelin and des-acyl ghrelin production
could help regulate the balance between adipogenesis and lipolysis
in response to nutritional status.
[0013] The successful creation of peptidic ghrelin analogues that
separate the GH-modulating effects of ghrelin from the effects on
weight gain and appetite also provides strong evidence for the
existence and physiological relevance of other receptor subtypes.
(Halem, H. A.; Taylor, J. E.; Dong, J. Z.; Shen, Y.; Datta, R.;
Abizaid, A,; Diano, S.; Horvath, T. L.; Culler, M. D. A novel
growth hormone secretagogue-1a receptor antagonist that blocks
ghrelin-induced growth hormone secretion but induces increased body
weight gain. Neuroendocrinol. 2005, 81, 339-349; Halem, H. A.;
Taylor, J. E.; Dong, J. Z.; Shen, Y.; Datta, R.; Abizaid, A.;
Diano, S.; Horvath, T.; Zizzari, P.; Bluet-Pajot, M.-T.; Epelbaum,
J.; Culler, M. D. Novel analogs of ghrelin: physiological and
clinical implications. Eur. J. Endocrinol, 2004, 151, S71-S75.)
BIM-28163 functions as an antagonist at the GHS-R1a receptor and
inhibits receptor activation by native ghrelin. However, this same
molecule is a full agonist with respect to stimulating weight gain
and food intake. Additionally, the existence of a still
uncharacterized receptor subtype has been proposed based on binding
studies in various tissues that showed differences between peptidic
and non-peptidic GHS. (Ong, H.; Menicoll, N.; Escher, F.; Collu,
R.; Deghenghi, R.; Locatelli, V.; Ghigo, E.; Muccioli, G.; Boghen,
M.; Nilsson, M. Endocrinology 1998, 139, 432-435.) Differences
between overall GHS-R expression and that of the GHS-R1a subtype in
rat testis have been reported. (Barreiro, M. L.; Suominen, J. S.;
Gaytan, F.; Pinilla, L.; Chopin, L. K.; Casanueva, F. F.; Dieguez,
C.; Aguilar, E.; Toppari, J.; Tena-Sempere, M. Developmental,
stage-specific, and hormonally regulated expression of growth
hormone secretagogue receptor messenger RNA in rat testis. Biol.
Reproduction 2003, 68, 1631-1640.) A GHS-R subtype on cholinergic
nerves is postulated as an explanation for the differential actions
of ghrelin and a peptidic GHS on neural contractile response
observed during binding studies at the motilin receptor.
(Depoortere, I.; Thijs, T.; Thielemans, L.; Robberecht, P.;
Peeters, T. L. Interaction of the growth hormone-releasing peptides
ghrelin and growth hormone-releasing peptide-6 with the motilin
receptor in the rabbit gastric antrum. J. Pharmacol. Exp. Ther.
2003, 305, 660-667.) Finally, the macrocyclic ghrelin agonists
described in WO 2006/009645 and WO 2006/009674 report the
separation of the GI effects from the GH-release effects in animal
models, also suggesting that different subtypes are involved in
these physiological effects.
[0014] The variety of activities associated with the ghrelin
receptor could also be due to different agonists activating
different signaling pathways as has been shown for ghrelin and
adenosine, both of which interact as agonists at GHS-R1a (Carreira,
M. C.; Camina, J. P.; Smith, R. G.; Casanueva, F. F.
Agonist-specific coupling of growth hormone secretagogue receptor
type 1a to different intracellular signaling systems. Role of
adenosine. Neuroendocrinology 2004, 79, 13-25.)
[0015] The functional activity of a GPCR has been shown to often
require the formation of dimers or other multimeric complexes with
itself or other proteins. (Prinster, S. C.; Hague, C.; Hall, R. A.
Heterodimerization of G protein-coupled receptors: specificity and
functional significance. Pharmacol. Rev. 2005, 57, 289-298; Hansen,
J. L.; Sheikh, S. P. Functional consequences of 7.TM. receptor
dimerization. Eur. J. Pharm. Sci. 2004, 23, 301-317; Park, P. S.;
Filipek, S.; Wells, J. W.; Palczewski, K. Oligomerization of G
protein-coupled receptors: past, present, and future. Biochemistry
2004, 43, 15643-15656; Rios, C. D.; Jordan, B. A.; Gomes, I.; Devi,
L. A. G-protein-coupled receptor dimerization: modulation of
receptor function. Pharmacol. Ther. 2001, 92, 71-87; Devi, L. A.
Heterodimerization of G-protein-coupled receptors: pharmacology,
signaling and trafficking. Trends Pharmacol. Sci. 2001, 22,
532-537.) Likewise, the activity of the ghrelin receptor might also
be at least partially governed by such complexes. For example,
certain reports indicate that interaction of GHS-R1a with GHRH
(Cunha, S. R.; Mayo, K. E. Ghrelin and growth hormone (GH)
secreatagogues potentiate GH-releasing hormone (GHRH)-induced
cyclic adenosine 3',5'-monophosphate production in cells expressing
transfected GHRH and GH secretagogue receptors. Endocrinology 2002,
143, 4570-4582; Malagon, M. M.; Luque, R. M.; Ruiz-Guerrero, E.;
Rodriguez-Pacheco, F.; Garcia-Navarro, S.; Casanueva, F. F.;
Gracia-Navarro, F.; Castano, J. P. Intracellular signaling
mechanisms mediating ghrelin-stimulated growth hormone release in
somatotropes Endocrinology 2003, 144, 5372-5380.) or between
receptor subtypes (Chan, C. B.; Cheng, C. H. K. Identification and
functional characterization of two alternatively spliced growth
hormone secretagogue receptor transcripts from the pituitary of
black seabream Acanthopagrus schlegeli. Mol. Cell. Endocrinol.
2004, 214, 81-95.) may be involved in modulating the function of
the receptor.
[0016] Further, the appetite regulating effects of ghrelin have
been attributed to the constitutive activity of the receptor.
(Holst, B. Schwartz, T. Ghrelin receptor mutations--too little
height and too much hunger. J. Clin. Invest. 2006, 116, 637-641;
Holst, B.; Schwartz, T. W. Constitutive ghrelin receptor activity
as a signaling set-point in appetite regulation. Trends Pharmacol.
Sci. 2004, 25, 113-117; Holst, B.; Holliday, N. D.; Bach, A.;
Elling, C. E.; Cox, H. M.; Schwartz, T. W. Common structural basis
for constitutive activity of the ghrelin receptor family. J. Biol.
Chem. 2004, 279, 53806-53817; Holst, B.; Cygankiewicz, A.; Jensen,
T. H.; Ankersen, M.; Schwartz, T. W. High constitutive signaling of
the ghrelin receptor--identification of a potent inverse agonist.
Mol. Endocrinol. 2003, 17, 2201-221.) The recent observation that
humans possessing a mutation in the ghrelin receptor that impairs
constitutive activity are of short stature suggests the importance
of the constitutive activity to the normal in vivo function of this
receptor. (Pantel, J.; Legendre, M. Cabrol, S.; et al. Loss of
constitutive activity of the growth hormone secretagogue receptor
in familial short stature. J. Clin. Invest. 2006, 116,
760-768.)
[0017] The vast majority of reported approaches to exploiting the
ghrelin receptor for therapeutic purposes have focused on
modulating metabolic functions. Similarly, the vast majority of
literature on GHS focuses on conditions that can be treated via its
GH promoting actions. Some embodiments of the invention described
herein, in particular, take advantage of selective activation of
the ghrelin receptor to provide an avenue for the treatment of
diseases characterized by GI dysmotility. The improved GI motility
observed with ghrelin demonstrates that ghrelin agonists may be
useful in correcting conditions associated with reduced or
restricted motility (Murray, C. D. R.; Kamm, M. A.; Bloom, S. R.;
Emmanuel, A. V. Ghrelin for the gastroenterologist: history and
potential. Gastroenterology 2003, 125, 1492-1502; Fujino, K.; Inui,
A.; Asakawa, A.; Kihara, N.; Fujimura, M.; Fujimiya, M. Ghrelin
induces fasting motor activity of the gastrointestinal tract in
conscious fed rats. J. Physiol. 2003, 550, 227-240; Edholm, T.;
Levin, F.; Hellstrom, P. M.; Schmidt, P. T. Ghrelin stimulates
motility in the small intestine of rats through intrinsic
cholinergic neurons. Regul. Pept. 2004, 121, 25-30; Locatelli, V.;
Bresciani, E.; Bulgarelli, I.; Rapetti, D.; Torsello, A.; Rindi,
G.; Sibilia, V. Netti, C. Ghrelin in gastroenteric pathophysiology.
J. Endocrinol. Invest. 2005, 28, 843-848; Peeters, T. L. Ghrelin: a
new player in the control of gastrointestinal functions. Gut 2005,
54, 1638-1649.)
[0018] Included among these conditions is postoperative ileus (P O
I, Luckey, A.; Livingston, E.; Tache, Y. Mechanisms and treatment
of postoperative ileus. Arch. Surg. 2003, 138, 206-214; Baig, M.
K.; Wexner, S. D. Postoperative ileus: a review. Dis. Colon Rectum
2004, 47, 516-526). POI is defined as the impairment of GI motility
that routinely occurs following abdominal, intestinal,
gynecological and pelvic surgeries. In the U.S. alone, 2.1 million
surgeries annually can induce POI, accounting for an economic
impact of over $1 billion. POI is considered a deleterious response
to surgical manipulation with a variable duration that generally
persists for at least 72 hours. It is characterized by pain,
abdominal distention or bloating, nausea and vomiting, accumulation
of gas and fluids in the bowel, and delayed passage of stool.
Patients are neither able to tolerate oral feeding nor to have
bowel movements until gut function returns. POI leads to numerous
undesirable consequences, including increased patient morbidity,
the costly prolongation of hospital stays and, further, is a major
cause of hospital readmission. In addition, opiate drugs given as
analgesics after surgery exacerbate this condition due to their
well-recognized side effect of inhibiting bowel function.
[0019] Surgical manipulation of the stomach or intestine causes a
disorganization of the gut-brain signaling pathways, impairing GI
activity and triggering POI. Ghrelin acts locally in the stomach to
stimulate and coordinate the firing of vagal afferent neurons and
thereby modulate gut motility. Thus, ghrelin accelerates gastric
emptying in humans (Petters, T. L. Potential of ghrelin as a
therapeutic approach for gastrointestinal motility disorders. Curr.
Opin. Pharmacol. 2006, 6, 553-558; Tack, J.; Depoortere, I.;
Bisschops, R.; Delporte, C.; Coulie, B.; Meulemans, A.; Janssens,
J.; Peeters, T. Influence of ghrelin on interdigestive
gastrointestinal motility in humans. Gut 2006, 55, 327-333; Inui,
A.; Asakawa, A.; Bowers, C. Y.; Mantovani, G.; Laviano, A.; Meguid,
M. M.; Fujimiya, M. Ghrelin, appetite, and gastric motility: the
emerging role of the stomach as an endocrine organ. FASEB J. 2004,
18, 439-456; Peeters, T. L. Central and peripheral mechanisms by
which ghrelin regulates gut motility. J. Physiol. Pharmacol. 2003,
54(Supp. 4), 95-103.) and is a potent agent proven to treat ileus
in animal models (Trudel, L.; Tomasetto, C.; Rio, M. C.; Bouin, M.;
Plourde, V.; Eberling, P.; Poitras, P. Ghrelin/motilin-related
peptide is a potent prokinetic to reverse gastric postoperative
ileus in rats. Am. J. Physiol. 2002, 282, G948-G952; Trudel, L.;
Bouin, M.; Tomasetto, C.; Eberling, P.; St-Pierre, S.; Bannon, P.;
L'Heureux, M. C.; Poitras, P. Two new peptides to improve
post-operative gastric ileus in dog. Peptides 2003, 24, 531-534; De
Winter, B. Y.; De Man, J. G.; Seerden, T. C.; Depoortere, I.;
Herman, A. G.; Peeters, T. L.; Pelckmans, P. A. Effect of ghrelin
and growth hormone-releasing peptide 6 on septic ileus in mice.
Neurogastroenterol. Motil. 2004, 16, 439-446.). Ghrelin agonists
can duplicate the GI stimulating effects of ghrelin, thus targeting
directly the underlying cause of POI to accelerate normalization of
gut function and enable more rapid discharge from the hospital.
(Kitazawa, T.; De Smet, B.; Verbeke, K.; Depoortere, I.; Peeters,
T. L. Gastric motor effects of peptide and non-peptide ghrelin
agonists in mice in vivo and in vitro. Gut 2005, 54, 1078-1084;
Poitras, P.; Polyino, W. J.; Rocheleau, B. Gastrokinetic effect of
ghrelin analog RC-1139 in the rat. Effect on post-operative and on
morphine induced ileus. Peptides 2005, 26, 1598-1601.) The reported
anti-inflammatory actions of ghrelin may also play a role in
ameliorating this condition. (Granado, M.; Priego, T.; Martin, A.
I; Villanua, M. A.; Lopez-Calderon, A. Anti-inflammatory effect of
the ghrelin agonist growth hormone-releasing peptide-2 (GHRP-2) in
arthritic rats. Am. J. Physiol. Endocrinol. Metab. 2005, 288,
E486-E492; Iseri, S. O.; Sener, G.; Yuksel, M.; Contuk, G.;
Cetinel, S.; Gedik, N.; Yegen, B. C. Ghrelin against
alendronate-induced gastric damage in rats. J. Endocrinol. 2005,
187, 399-406.)
[0020] Intravenous administration is often the preferred route of
treatment for POI due to the impaired GI motility in these patients
that impedes oral therapy. No agent is currently approved by the
U.S. FDA specifically for the treatment of POI.
[0021] Another major motility disorder is gastroparesis, a
particular problem for both type I and type II diabetics.
(Camilleri, M. Advances in diabetic gastroparesis. Rev.
Gastroenterol. Disord. 2002, 2, 47-56; Abell, T. L.; Bernstein, R.
K.; Cutts, T.; Treatment of gastroparesis: a multidisciplinary
clinical review. Neurogastrenterol. Motil. 2006, 18, 263-283;
Camilleri, M. Diabetic gastroparesis. New Eng. J. Med. 2007, 356,
820-829.) Gastroparesis ("stomach paralysis") is a syndrome
characterized by delayed gastric emptying in the absence of any
mechanical obstruction. It is variably characterized by abdominal
pain, nausea, vomiting, weight loss, anorexia, early satiety,
malnutrition, dehydration, gastroesophageal reflux, cramping and
bloating. This chronic condition can lead to frequent
hospitalization, increased disability and decreased quality of
life. Severe, symptomatic gastroparesis is common in individuals
suffering from diabetes, affecting from 5-10% of diabetics for a
total patient population of 1 million in the U.S. alone. Neuropathy
is a frequent, debilitating complication of diabetes. Visceral
neuropathy results in GI dysfunction, especially involving the
stomach, leading to impaired gastric motility. Ghrelin promotes
gastric emptying both by stimulating the vagus nerve and via direct
prokinetic action at the gastric mucosa. Moreover, recent clinical
studies indicate that intravenous administration of the natural
ghrelin peptide is an effective acute therapy in gastroparesis
patients. (Binn, M.; Albert, C.; Gougeon, A.; Maerki, H.; Coulie,
B.; Lemoyne, M.; Rabasa Lhoret, R.; Tomasetto, C.; Poitras, P.
Ghrelin gastrokinetic action in patients with neurogenic
gastroparesis. Peptides 2006, 27, 1603-1606; Murray, C. D. R.;
Martin, N. M.; Patterson, M.; Taylor, S.; Ghatei, M. A.; Kamm, M.
A.; Johnston, C.; Bloom, S. R.; Emmanuel, A. V. Ghrelin enhances
gastric emptying in diabetic gastroparesis: a double-blind,
placebo-controlled, cross-over study. Gut 2005, 54, 1693-1698;
Tack, J.; Depoortere, I.; Bisschops, R.; Verbeke, K.; Janssens, J.;
Peeters, T. Influence of ghrelin on gastric emptying and
meal-related symptoms in idiopathic gastroparesis. Aliment.
Pharmacol. Ther. 2005, 22, 847-853.)
[0022] A ghrelin agonist would therefore be highly effective in
overcoming the fundamental motility barrier faced by gastroparesis
patients and correcting this condition. As with POI, no accepted or
efficacious therapy for diabetic gastroparesis is available and
most current therapies aim to provide only symptomatic relief.
Further, many of the therapeutics in development have a mechanism
of action similar to earlier products that have failed in this
indication. Surgical procedures may ameliorate the disease process,
but offer no possibility of cure.
[0023] Post-surgical gastroparesis syndrome is a complication
resulting from surgery characterized by delayed gastric emptying,
postprandial nausea and vomiting, and abdominal pain. (Eckhauser,
F. E., et al. Am. Surg. 1998, 64, 711-717; Tanaka, M. Surg. Today
2005, 35, 345-350.) These surgeries include gastrectomy,
pancreatoduodenectomy, gastrojejunostomy in patients with
pancreatic cancer and gastric surgery, as well as in patients with
liver cirrhosis. (Doberneck, R. C.; Berndt, G. A. Delayed gastric
emptying after palliative gastrojejunostomy for carcinoma of the
pancreas. Arch. Surg. 1987, 122, 827-829; Bar-Natan, M.; Larson, G.
M.; Stephens, G.; Massey, T. Delayed gastric emptying after gastric
surgery. Am. J. Surg. 1996, 172, 24-28; Cohen, A. M.; Ottinger, L.
W. Delayed gastric emptying following gastrectomy. Ann. Surg. 1976,
184, 689-696; Isobe, H.; Sakai, H.; Satoh, M.; Sakamoto, S.;
Nawata, H. Delayed gastric emptying in patients with liver
cirrhosis. Dig. Dis. Sci. 1994, 39, 983-987.) The only reported
pharmaceutical agents shown to be useful for this syndrome are
cisapride and erythromycin. (Takeda, T.; Yoshida, J.; Tanaka, M.;
Matsunaga, H.; Yamaguchi, K.; Chijiiwa, K. Delayed gastric emptying
after Billroth I pylorus preserving pancreatoduodenectomy. Effect
of postoperative time and cisapride. Ann. Surg. 1999, 229, 223-229;
Heidenreich, A.; Wille, S.; Hofmann, R. J. Urology 2000, 163, 545.)
However, cisapride was removed from the market due, at least in
part, to the appearance of life-threatening cardiac arythmia side
effects. Further, erythromycin is not a desirable treatment due to
the antibiotic activity potentially giving rise to resistance
should it be used for non-infective purposes.
[0024] Opioid-induced bowel dysfunction (OBD, Kurz, A.; Sessler, D.
J. Opioid-Induced Bowel Dysfunction. Drugs 2003, 63, 649-671.) is
the term applied to the confluence of symptoms involving the
reduced GI motility that results from treatment with opioid
analgesics. Approximately 40-50% of patients taking opioids for
pain control experience OBD. It is characterized by hard, dry
stools, straining, incomplete evacuation, bloating, abdominal
distension and increased gastric reflux. In addition to the obvious
short-term distress, this condition leads to physical and
psychological deterioration in patients undergoing long term opioid
treatment. Further, the dysfunction can be so severe as to become a
dose-limiting adverse effect that actually prevents adequate pain
control. As with POI, a ghrelin agonist can be expected to
counteract the dysmotility resulting from opioid use.
[0025] Two less common conditions may also be helped through the GI
motility stimulation effects of ghrelin and ghrelin agonists. Short
bowel syndrome is a condition that occurs after resection of a
substantial portion of small intestine and is characterized by
malnutrition. Patients are observed to have decreased ghrelin
levels resulting from loss of the ghrelin-producing neuroendocrine
cells of the intestine. It is possible the short bowel feeds back
on the release of the hormone. (Krsek, M.; Rosicka, M.; Haluzik,
M.; et al. Plasma ghrelin levels in patients with short bowel
syndrome. Endocr. Res. 2002, 28, 27-33.) Chronic intestinal
pseudo-obstruction is a syndrome defined by the presence of chronic
intestinal dilation and dysmotility in the absence of mechanical
obstruction or inflammation. Both genetic and acquired causes are
known to result in this disorder, which affects high numbers of
individuals worldwide annually. (Hirano, I.; Pandolfino, J. Chronic
intestinal pseudo-obstruction. Dig. Dis. 2000, 18, 83-92.)
[0026] Other conditions and disorders that could be addressed
through stimulation of the ghrelin receptor are: constipation such
as associated with the hypomotility phase of irritable bowel
syndrome (IBS), delayed gastric emptying associated with wasting
conditions, gastroesophageal reflux disease (GERD), gastric ulcers
(Sibilia, V.; Muccioli, G.; Deghenghi, R.; Pagani, F.; DeLuca, V.;
Rapetti, D.; Locatelli, V.; Netti, C. Evidence for a role of the
GHS-R1a receptor in ghrelin inhibition of gastric acid secretion in
the rat. J. Neuroendocrinol. 2006, 18, 122-128; Sibilia, V.; Rindi,
G.; Pagani, F.; Rapetti, D.; Locatelli, V.; Torsello, A.;
Campanini, N.; Degenghi, R.; Netti, C. Ghrelin protects against
ethanol-induced gastric ulcers in rats: studies on the mechanism of
action. Endocrinology 2003, 144, 353-359.) and Crohn's disease.
Ghrelin and ghrelin agonists also have been described as treatments
for nausea, emesis or symptoms thereof. (U.S. Pat. Appl. Pub. No.
2005/277677; Rudd, J. A.; Ngan, M. P.; Wai, M. K.; King, A. G.;
Witherington, J.; Andrews, P. L. R.; Sanger, G. J. Anti-emetic
activity of ghrelin in ferrets exposed to the cytotoxic anti-cancer
agent cisplatin. Neurosci. Lett. 2006, 392, 79-83.)
[0027] Additionally, GI dysmotility is a significant problem in
other mammals as well. For example, the motility dysfunction termed
ileus or colic is the number one cause of mortality among horses.
Further, ileus is one of the most common complications of equine
intestinal surgery, in other words, post-operative ileus. This
condition may also have a non-surgical etiology. Some horses may be
predisposed to ileus based upon the anatomy and functioning of
their digestive tract. Virtually any horse is susceptible to colic
with only minor differences based upon age, sex and breed.
Additionally, ileus may affect other animals, for example canines.
(Roussel, A. J., Jr.; Cohen, N. D.; Hooper, R. N.; Rakestraw, P. C.
Risk factors associated with development of postoperative ileus in
horses. J. Am. Vet. Med. Assoc. 2001, 219, 72-78; Van Hoogmoed, L.
M.; Nieto, J. E.; Snyder, J. R.; Harmon, F. A. Survey of prokinetic
use in horses with gastrointestinal injury. Vet. Surg. 2004, 33,
279-285.)
[0028] Further, many GI disorders are experienced simultaneously.
In particular when opioids are used for pain management during
surgery, OBD can exacerbate POI, which often results from
surgery.
[0029] Importantly, for most of the above conditions, no specific,
approved therapeutics exist and most therapies simply address
symptomatic relief. However, specific modulation of the ghrelin
receptor provides an opportunity to directly target the site of
pathophysiological disturbance to better treat the underlying
condition and improve clinical outcome. Further, unlike other
agents that interact at the ghrelin receptor, the macrocyclic
compounds of the invention are believed not to stimulate concurrent
GH secretion as demonstrated in animal models. This separation of
the gastrointestinal and GH effects has not previously been
reported for any modulators of this receptor. However, as already
mentioned, the existence of analogues that separate the appetite
control and GH modulatory effects associated with ghrelin has been
recently reported.
[0030] WO 01/00830 reports on short gastrointestinal peptides
(SGIP) that secrete growth hormone and also promote GI motility,
but these were not shown to be due to action at the ghrelin
receptor. Similarly, WO 2007/041278 describes peptide analogues of
ghrelin that stimulate GI motility. U.S. Pat. Nos. 6,548,501 and
6,852,722 discuss specific non-peptidic GHS compounds useful for
stimulation of GI motility. Similarly, WO 2006/010629, WO
2006/020930 and WO 2006/023608 describe ghrelin agonists (growth
hormone secretagogues) for use in GI disorders. Moreover, other
endogenous factors are known to stimulate secretion of GH, but do
not promote GI motility. Indeed, many actually inhibit this
physiological function. Specific receptor agonists such as the
compounds of the present invention have much better potential to be
selective and effective therapeutic agents.
[0031] However, these ghrelin agonists are typically used in higher
dose levels in order to effectively treat combination GI disorders.
For example, RC-1139 required a higher dose level (10 mg/kg) to
restore gastric emptying to normal values in rats with concurrent
conditions of POI and OBD than with POI alone (2.5 mg/kg). However,
this compound failed to accelerate gastric emptying in a rat model
of POI in combination with a higher dose of morphine (12 mg/kg)
even at levels up to 10 mg/kg. (WO 2006/020930).
[0032] Intl. Pat. Appl. WO 2006/009645 and WO 2006/009674 describe
the use of macrocyclic compounds as ghrelin modulators for use in
the treatment of GI disorders. Unexpectedly, and in contrast to
other agents that effect GI motility, these macrocyclic compounds
have been found to typically require the same dose level or
essentially the same dose level to treat the combination condition
as was effective for either POI or OBD individually.
[0033] These macrocyclic compounds are structurally distinct from
other compounds that have been found to interact at the ghrelin
receptor as agonists. For example, significant work was devoted to
the development of potent and selective GHS with a number of small
molecule derivatives now being known as has been recently
summarized. (Carpino, P. Exp. Opin. Ther. Patents 2002, 12,
1599-1618.) Specific GHS are described in the following: Intl. Pat.
Appl. Pubis. WO 89/07110; WO 89/07111; WO 92/07578; WO 93/04081; WO
94/11012; WO 94/13696; WO 94/19367; WO 95/11029; WO 95/13069; WO
95/14666; WO 95/17422; WO 95/17423; WO 95/34311; WO 96/02530; WO
96/15148; WO 96/22996; WO 96/22997; WO 96/24580; WO 96/24587; WO
96/32943; WO 96/33189; WO 96/35713; WO 96/38471; WO 97/00894; WO
97/06803; WO 97/07117; WO 97/09060; WO 97/11697; WO 97/15191; WO
97/15573; WO 97/21730; WO 97/22004; WO 97/22367; WO 97/22620; WO
97/23508; WO 97/24369; WO 97/34604; WO 97/36873; WO 97/38709; WO
97/40023; WO 97/40071; WO 97/41878; WO 97/41879; WO 97/43278; WO
97/44042; WO 97/46252; WO 98/03473; WO 98/10653; WO 98/18815; WO
98/22124; WO 98/46569; WO 98/51687; WO 98/58947; WO 98/58948; WO
98/58949; WO 98/58950; WO 99/08697; WO 99/08699; WO 99/09991; WO
99/36431; WO 99/39730; WO 99/45029; WO 99/58501; WO 99/64456; WO
99/65486, WO 99/65488; WO 00/01726; WO 00/10975; WO 00/48623; WO
00/54729; WO 01/47558; WO 01/92292; WO 01/96300; WO 01/97831; WO
2004/021984; WO 2005/039625; WO 2005/046682; WO 2005/070884; WO
2006/044359; U.S. Pat. No. 3,239,345; U.S. Pat. No. 4,036,979; U.S.
Pat. No. 4,411,890; U.S. Pat. No. 5,492,916; U.S. Pat. No.
5,494,919; U.S. Pat. No. 5,559,128; U.S. Pat. No. 5,663,171; U.S.
Pat. No. 5,721,250; U.S. Pat. No. 5,721,251; U.S. Pat. No.
5,723,616; U.S. Pat. No. 5,726,319; U.S. Pat. No. 5,767,124; U.S.
Pat. No. 5,798,337; U.S. Pat. No. 5,830,433; U.S. Pat. No.
5,919,777; U.S. Pat. No. 6,034,216; U.S. Pat. No. 6,548,501; U.S.
Pat. No. 6,559,150; U.S. Pat. No. 6,576,686; U.S. Pat. No.
6,639,076; U.S. Pat. No. 6,686,359; U.S. Pat. No. 6,828,331; U.S.
Pat. No. 6,861,409; U.S. Pat. No. 6,919,315; U.S. Pat. No.
7,034,050 and U.S. Pat. Appl. Nos. 2002/0168343; 2003/100494;
2003/130284; 2003/186844; 2005/187237; 2005/233981.
[0034] Despite this immense body of work, cyclic compounds have
rarely been found to act at the ghrelin receptor. When they have,
antagonist activity has been more prevalent. For example, the
14-amino acid compound, vapreotide, an SRIH-14 agonist and
somatostatin mimetic, was demonstrated to be a ghrelin antagonist.
(Deghenghi R, Papotti M, Ghigo E, et al. Somatostatin octapeptides
(lanreotide, octreotide, vapreotide, and their analogs) share the
growth hormone-releasing peptide receptor in the human pituitary
gland. Endocrine 2001, 14, 29-33.) The binding and antagonist
activities of analogues of cortistatin, a cyclic neuropeptide known
to bind nonselectively to somatostatin receptors, to the growth
hormone secretagogue receptor have been reported. (Intl. Pat. Appl.
WO 03/004518; Deghenghi R, Broglio F, Papotti M, et al. Targeting
the ghrelin receptor--Orally active GHS and cortistatin analogs.
Endocrine 2003, 22, 13-18; Sibilia, V.; Muccioli, G.; Deghenghi,
R.; Pagani, F.; DeLuca, V.; Rapetti, D.; Locatelli, V.; Netti, C.
Evidence for a role of the GHS-R1a receptor in ghrelin inhbition of
gastric acid secretion in the rat. J. Neuroendocrinol. 2006, 18,
122-128.) In particular, one of these analogues, EP-01492
(cortistatin-8) has been advanced into preclinical studies for the
treatment of obesity as a ghrelin antagonist. These compounds
exhibit an IC.sub.50 of 24-33 nM. In addition, these cyclic
compounds and their derivatives, plus their use with metal binding
agents have been described for their ability to be useful for
radiodiagnostic or radiotherapeutic use in the treatment of tumors
and acromegaly.
[0035] Cyclic and linear analogues of growth hormone 177-191 have
been studied as treatments for obesity (WO 99/12969), with one
particular compound, AOD9604, having entered the clinic for this
indication. A compound already studied that is most similar to the
molecules of the present invention is the GHS, G-7203
(EC.sub.50=0.43 nM), the cyclic peptide analogue of the growth
hormone releasing peptide, GHRP-2. (Elias, K. A.; Ingle, G. S.;
Burnier, J. P.; Hammonds, G.; McDowell, R. S.; Rawson, T. E.;
Somers, T. C.; Stanley, M. S.; Cronin, M. J. In vitro
characterization of four novel classes of growth hormone-releasing
peptide. Endocrinol. 1995, 136, 5694-5699.) However, simplification
of this cyclic derivative led to still potent, linear compounds,
whereas, for compounds of the invention, linear analogues have been
found to be devoid of ghrelin receptor activity.
[0036] The macrocyclic compounds of the invention have been shown
to possess ghrelin modulating activity, and in particular
embodiments, as agonists. However, unlike other agonists of this
receptor, the compounds of the invention unexpectedly can stimulate
GI motility resulting from multiple GI disorders at the same dose
level, or essentially the same dose level, as is efficacious for a
single disorder.
SUMMARY OF THE INVENTION
[0037] The present invention provides novel
conformationally-defined macrocyclic compounds. These compounds can
function as modulators, in particular, agonists of the ghrelin
(growth hormone secretagogue) receptor (GHS-R1a).
[0038] According to aspects of the present invention, the present
invention relates to compounds according to formula I, II, III
and/or IV:
##STR00001##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof, wherein:
[0039] R.sub.1 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.1 and R.sub.2 together form a 4-, 5-, 6-, 7- or
8-membered ring, optionally comprising an O, S or N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below, or alternatively R.sub.1 and R.sub.9 together form a
3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as defined below;
[0040] R.sub.2 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.1 and R.sub.2 together form a 4-, 5-, 6-, 7- or
8-membered ring, optionally comprising an O, S or N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below; or alternatively R.sub.2 and R.sub.9 together form a
3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as defined below;
[0041] R.sub.3 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.3 and R.sub.4 together form a 3-, 4-, 5-, 6- or
7-membered ring, optionally comprising an O or S atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below, or alternatively, R.sub.3 and R.sub.7 or R.sub.3 and
R.sub.11 together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic
ring, optionally comprising an O, S or additional N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below;
[0042] R.sub.4 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.4 and R.sub.3 together form a 3-, 4-, 5-, 6- or
7-membered ring, optionally comprising an O or S atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below, or alternatively R.sub.4 and R.sub.7 or R.sub.4 and R.sub.11
together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring,
optionally comprising an O, S or additional N atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below;
[0043] R.sub.5 and R.sub.6 are each independently hydrogen or the
side chain of an amino acid or alternatively R.sub.5 and R.sub.6
together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally
comprising an O, S or N atom in the ring, wherein the ring is
optionally substituted with R.sub.8 as defined below;
[0044] R.sub.7 is hydrogen, lower alkyl, substituted lower alkyl,
cycloalkyl, substituted cycloalkyl, a heterocyclic group, or a
substituted heterocyclic group, or alternatively R.sub.3 and
R.sub.7 or R.sub.4 and R.sub.7 together form a 4-, 5-, 6-, 7- or
8-membered heterocyclic ring optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as described below;
[0045] R.sub.8 is substituted for one or more hydrogen atoms on the
3-, 4-, 5-, 6-, 7- or 8-membered ring structure and is
independently selected from the group consisting of alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, oxo, amino, halogen, formyl, acyl, carboxy,
carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido,
amidino, mercapto, sulfinyl, sulfonyl and sulfonamido, or,
alternatively, R.sub.8 is a fused cycloalkyl, a substituted fused
cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic,
a fused aryl, a substituted fused aryl, a fused heteroaryl or a
substituted fused heteroaryl ring when substituted for hydrogen
atoms on two adjacent atoms;
[0046] X is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+; [0047] wherein
R.sub.9 is hydrogen, lower alkyl, substituted lower alkyl,
sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen, lower
alkyl, or substituted lower alkyl, or alternatively R.sub.9 and
R.sub.1 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O, S or additional N atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
above;
[0048] Z.sub.1 is O or NR.sub.11, [0049] wherein R.sub.H is
hydrogen, lower alkyl, or substituted lower alkyl, or alternatively
R.sub.3 and R.sub.11 or R.sub.4 and R.sub.11 together form a 4-,
5-, 6-, 7- or 8-membered heterocyclic ring, optionally comprising
an O, S or additional N atom in the ring, wherein the ring is
optionally substituted with R.sub.8 as defined above;
[0050] Z.sub.2 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl;
[0051] m, n and p are each independently 0, 1 or 2;
[0052] T is a bivalent radical of formula V:
--U--(CH.sub.2).sub.d--W--Y--Z--(CH.sub.2).sub.e-- (V) [0053]
wherein d and e are each independently 0, 1, 2, 3, 4 or 5; Y and Z
are each optionally present; U is --CR.sub.21R.sub.22-- or
--C(.dbd.O)-- and is bonded to X of formula I; W, Y and Z are each
independently selected from the group consisting of --O--,
--NR.sub.23--, --S--, --SO--, --SO.sub.2--, --C(.dbd.O)--O--,
--O--C(.dbd.O)--, --C(.dbd.O)--NH--, --NH--C(.dbd.O)--,
--SO.sub.2--NH--, --NH--SO.sub.2--, --CR.sub.24R.sub.25--,
--CH.dbd.CH-- with the configuration Z or E, and the ring
structures below:
[0053] ##STR00002## [0054] Or [0055] wherein G.sub.1 and G.sub.2
are each independently a covalent bond or a bivalent radical
selected from the group consisting of --O--, --NR.sub.39--, --S--,
--SO--, --SO.sub.2--, --C(.dbd.O)--, --C(.dbd.O)NH--,
--O--C(.dbd.)--, --NH--C(.dbd.O)--, --SO.sub.2--NH--,
--NH--SO.sub.2--, --CR.sub.40R.sub.41--, --CH.dbd.CH-- with the
configuration Z or E, and --C.ident.C--; with G.sub.1 being bonded
closest to the group U; wherein any carbon atom in the rings not
otherwise defined, is optionally replaced by N, with the proviso
that the ring cannot contain more than four N atoms; K.sub.1,
K.sub.2, K.sub.3, K.sub.4 and K.sub.5 are each independently O,
NR.sub.42 or S, wherein R.sub.42 is as defined below; [0056]
R.sub.21 and R.sub.22 are each independently hydrogen, lower alkyl,
or substituted lower alkyl, or alternatively R.sub.21 and R.sub.22
together form a 3- to 12-membered cyclic ring optionally comprising
one or more heteroatoms selected from the group consisting of O, S
and N, wherein the ring is optionally substituted with R.sub.8 as
defined above; [0057] R.sub.23, R.sub.39 and R.sub.42 are each
independently hydrogen, alkyl, substituted alkyl, cycloalkyl,
substituted cycloalkyl, heterocyclic, substituted heterocyclic,
aryl, substituted aryl, heteroaryl, substituted heteroaryl, formyl,
acyl, carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or
sulfonamido; [0058] R.sub.24 and R.sub.25 are each independently
hydrogen, lower alkyl, substituted lower alkyl, R.sub.AA, wherein
R.sub.AA is a side chain of an amino acid such as a standard or
unusual amino acid, or alternatively R.sub.24 and R.sub.25 together
form a 3- to 12-membered cyclic ring optionally comprising one or
more heteroatoms selected from the group consisting of O, S and N;
or alternatively one of R.sub.24 or R.sub.25 is hydroxy, alkoxy,
aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino
while the other is hydrogen, lower alkyl or substituted lower
alkyl, except when the carbon to which R.sub.24 and R.sub.25 are
bonded is also bonded to another heteroatom; [0059] R.sub.26,
R.sub.31, R.sub.35 and R.sub.38 are each optionally present and,
when present, are substituted for one or more hydrogen atoms on the
indicated ring and each is independently selected from the group
consisting of halogen, trifluoromethyl, alkyl, substituted alkyl,
cycloalkyl, substituted cycloalkyl, a heterocyclic group, a
substituted heterocyclic group, aryl, substituted aryl, heteroaryl,
substituted heteroaryl, hydroxy, alkoxy, aryloxy, amino, formyl,
acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, cyano, nitro, mercapto, sulfinyl,
sulfonyl and sulfonamido; [0060] R.sub.27 is optionally present and
is substituted for one or more hydrogen atoms on the indicated ring
and each is independently selected from the group consisting of
alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy, carboxyalkyl,
carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino,
mercapto, sulfinyl, sulfonyl and sulfonamido; [0061] R.sub.28,
R.sub.29, R.sub.30, R.sub.32, R.sub.33, R.sub.34, R.sub.36 and
R.sub.37 are each optionally present and, when no double bond is
present to the carbon atom to which it is bonded in the ring, two
groups are optionally present, and when present, is substituted for
one hydrogen present in the ring, or when no double bond is present
to the carbon atom to which it is bonded in the ring, is
substituted for one or both of the two hydrogen atoms present on
the ring and each is independently selected from the group
consisting of alkyl, substituted alkyl, cycloalkyl, substituted
cycloalkyl, a heterocyclic group, a substituted heterocyclic group,
aryl, substituted aryl, heteroaryl, substituted heteroaryl,
hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy,
carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido,
amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and, only if a
double bond is present to the carbon atom to which it is bonded,
halogen; and [0062] R.sub.40 and R.sub.41 are each independently
hydrogen, lower alkyl, substituted lower alkyl, R.sub.AA as defined
above, or alternatively R.sub.40 and R.sub.41 together form a 3- to
12-membered cyclic ring optionally comprising one or more
heteroatoms selected from the group consisting of O, S and N
wherein the ring is optionally substituted with R.sub.8 as defined
above, or alternatively one of R.sub.40 and R.sub.41 is hydroxy,
alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or
guanidino, while the other is hydrogen, lower alkyl or substituted
lower alkyl, except when the carbon to which R.sub.40 and R.sub.41
are bonded is also bonded to another heteroatom; [0063] with the
proviso that T is not an amino acid residue, dipeptide fragment,
tripeptide fragment or higher order peptide fragment comprising
standard amino acids;
##STR00003##
[0063] or a pharmaceutically acceptable salt, hydrate, solvate,
optical isomer, enantiomer, diastereomer, racemate or
stereochemical mixture thereof, wherein:
[0064] R.sub.50 is --(CH.sub.2).sub.ssCH.sub.3,
--CH(CH.sub.3)(CH.sub.2).sub.ttCH.sub.3,
--(CH.sub.2).sub.uuCH(CH.sub.3).sub.2, --C(CH.sub.3).sub.3,
--(CHR.sub.55).sub.vv--R.sub.56, or --CH(OR.sub.57)CH.sub.3,
wherein ss is 1, 2 or 3; tt is 1 or 2; uu is 0, 1 or 2; and vv is
0, 1, 2, 3 or 4; R.sub.55 is hydrogen or C.sub.1-C.sub.4 alkyl;
R.sub.56 is amino, hydroxy, alkoxy, cycloalkyl or substituted
cycloalkyl; and R.sub.57 is hydrogen, alkyl, acyl, amino acyl,
sulfonyl, carboxyalkyl or carboxyaryl;
[0065] R.sub.51 is hydrogen, C.sub.1-C.sub.4 alkyl or
C.sub.1-C.sub.4 alkyl substituted with hydroxy or alkoxy;
[0066] R.sub.52 is --(CHR.sub.58).sub.wwR.sub.59, wherein ww is 0,
1, 2 or 3; R.sub.58 is hydrogen, C.sub.1-C.sub.4 alkyl, amino,
hydroxy or alkoxy; R.sub.59 is aryl, substituted aryl, heteroaryl,
substituted heteroaryl, cycloalkyl or substituted cycloalkyl;
[0067] R.sub.53 is hydrogen or C.sub.1-C.sub.4 alkyl;
[0068] X.sub.2 is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+; [0069]
wherein R.sub.9 is hydrogen, lower alkyl, substituted lower alkyl,
sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen, lower
alkyl, or substituted lower alkyl;
[0070] Z.sub.5 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl; and
[0071] T.sub.2 is a bivalent radical of formula VI:
--U.sub.a--(CH.sub.2).sub.d--W.sub.a--Y.sub.a--Z.sub.a--(CH.sub.2).sub.e-
-- (VI) [0072] wherein d and e are independently 0, 1, 2, 3, 4 or
5; Y.sub.a and Z.sub.a are each optionally present; U.sub.a is
--CR.sub.60R.sub.61-- or --C(.dbd.O)-- and is bonded to X.sub.2 of
formula II, wherein R.sub.60 and R.sub.61 are each independently
hydrogen, lower alkyl, or substituted lower alkyl, or alternatively
R.sub.21 and R.sub.22 together form a 3- to 12-membered cyclic ring
optionally comprising one or more heteroatoms selected from the
group consisting of O, S and N, wherein the ring is optionally
substituted with R.sub.8 as defined above; W.sub.a, Y.sub.a and
Z.sub.a are each independently selected from the group consisting
of: --O--, --NR.sub.62--, --S--, --SO--, --SO.sub.2--,
--C(.dbd.O)--O--, --O--C(.dbd.O)--, --C(.dbd.O)--NH--,
--NH--C(.dbd.O)--, --SO.sub.2--NH--, --NH--SO.sub.2--,
--CR.sub.63R.sub.64--, --CH.dbd.CH-- with the configuration Z or E,
--C.ident.C--, and the ring structures depicted below:
[0072] ##STR00004## [0073] wherein G.sub.1 and G.sub.2 are as
defined above, and wherein any carbon atom in the ring is
optionally replaced by N, with the proviso that the aromatic ring
cannot contain more than four N atoms and the cycloalkyl ring
cannot contain more than two N atoms; [0074] R.sub.62 is hydrogen,
alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl,
carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or sulfonamido;
[0075] R.sub.63 and R.sub.64 are each independently hydrogen, lower
alkyl, substituted lower alkyl or R.sub.AA; or alternatively
R.sub.63 and R.sub.64 together form a 3- to 12-membered cyclic ring
optionally comprising one or more heteroatoms selected from the
group consisting of O, S and N; or alternatively one of R.sub.63
and R.sub.64 is hydroxy, alkoxy, aryloxy, amino, mercapto,
carbamoyl, amidino, ureido or guanidino, while the other is
hydrogen, lower alkyl or substituted lower alkyl, except when the
carbon to which R.sub.63 and R.sub.64 are bonded is also bonded to
another heteroatom; and R.sub.AA indicates the side chain of an
amino acid such as a standard or unusual amino acid; [0076]
R.sub.65 and R.sub.68 are each optionally present, and, when
present are substituted for one or more hydrogen atoms on the ring
and each is independently halogen, trifluoromethyl, alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl,
carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano,
nitro, mercapto, sulfinyl, sulfonyl or sulfonamido; [0077] R.sub.66
and R.sub.67 are each optionally present, and when no double bond
is present to the carbon atom to which it is bonded in the ring,
two groups are optionally present, and, when present, each is
substituted for one hydrogen present in the ring, or when no double
bond is present to the carbon atom to which it is bonded in the
ring, is substituted for one or both of the two hydrogen atoms
present on the ring and each is independently alkyl, substituted
alkyl, cycloalkyl, substituted cycloalkyl, heterocyclic,
substituted heterocyclic, aryl, substituted aryl, heteroaryl,
substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino,
formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl,
sulfonamido and, only if a double bond is present to the carbon
atom to which it is bonded, halogen; [0078] R.sub.69 is optionally
present, and when present is substituted for one or more hydrogen
atoms on the ring and each is independently alkyl, substituted
alkyl, cycloalkyl, substituted cycloalkyl, a heterocyclic group, a
substituted heterocyclic group, aryl, substituted aryl, heteroaryl,
substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino,
formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl or
sulfonamido; [0079] K.sub.6 is O or S; and [0080] ff is 1, 2, 3, 4
or 5; [0081] with the proviso that T.sub.2 is not an amino acid
residue, dipeptide fragment, tripeptide fragment or higher order
peptide fragment comprising standard amino acids;
##STR00005##
[0081] or a pharmaceutically acceptable salt, hydrate, solvate,
optical isomer, enantiomer, diastereomer, racemate or
stereochemical mixture thereof, wherein:
[0082] R.sub.70 is hydrogen, C.sub.1-C.sub.4 alkyl or alternatively
R.sub.70 and R.sub.71 together form a 4-, 5-, 6-, 7- or 8-membered
ring, optionally comprising an O, N or S atom in the ring, wherein
the ring is optionally substituted with R.sub.8a as defined
below;
[0083] R.sub.71 is hydrogen, --(CH.sub.2).sub.aaCH.sub.3,
--CH(CH.sub.3)(CH.sub.2).sub.bbCH.sub.3,
--(CH.sub.2).sub.ccCH(CH.sub.3).sub.2,
--(CH.sub.2).sub.dd--R.sub.76 or --CH(OR.sub.77)CH.sub.3 or,
alternatively R.sub.71 and R.sub.70 together form a 4-, 5-, 6-, 7-
or 8-membered ring, optionally comprising an O, N or S atom in the
ring, wherein the ring is optionally substituted with R.sub.8a as
defined below; wherein aa is 0, 1, 2, 3, 4 or 5; bb is 1, 2 or 3;
cc is 0, 1, 2 or 3; and dd is 0, 1, 2, 3 or 4; R.sub.76 is aryl,
substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or
substituted cycloalkyl; R.sub.77 is hydrogen, alkyl, acyl, amino
acyl, sulfonyl, carboxyalkyl or carboxyaryl;
[0084] R.sub.72 is C.sub.1-C.sub.4 alkyl; or alternatively R.sub.72
and R.sub.73 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O or S atom in the ring, wherein the ring
is optionally substituted with R.sub.8b as defined below;
[0085] R.sub.73 is hydrogen, or alternatively R.sub.73 and R.sub.72
together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally
comprising an O, S or N atom in the ring, wherein the ring is
optionally substituted with R.sub.8b as defined below;
[0086] R.sub.74 is hydrogen or C.sub.1-C.sub.4 alkyl or
alternatively R.sub.74 and R.sub.75 together form a 3-, 4-, 5-, 6-
or 7-membered ring, optionally comprising an O, N or S atom in the
ring, wherein the ring is optionally substituted with R.sub.8c as
defined below;
[0087] R.sub.75 is --(CHR.sub.78)R.sub.79 or alternatively R.sub.75
and R.sub.74 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O, N or S atom in the ring, wherein the
ring is optionally substituted with R.sub.8c as defined below;
wherein R.sub.78 is hydrogen, C.sub.1-C.sub.4 alkyl, amino, hydroxy
or alkoxy, and R.sub.79 is selected from the group consisting of
the following structures:
##STR00006## [0088] wherein E.sub.1, E.sub.2, E.sub.3, E.sub.4 and
E.sub.5 are each optionally present and when present are each
independently selected from the group consisting of halogen,
trifluoromethyl, alkyl, substituted alkyl, cycloalkyl, substituted
cycloalkyl, a heterocyclic group, a substituted heterocyclic group,
aryl, substituted aryl, heteroaryl, substituted heteroaryl,
hydroxy, alkoxy, aryloxy, cyano, sulfinyl, sulfonyl and
sulfonamido, and represent substitution at one or more available
positions on the monocyclic or bicyclic aromatic ring, wherein said
substitution is made with the same or different selected group
member, and J.sub.1 and J.sub.2 are each independently O or S;
[0089] R.sub.8a, R.sub.8b and R.sub.8c are each independently
substituted for one or more hydrogen atoms on the 3-, 4-, 5-, 6-,
7- or 8-membered ring structure and are independently selected from
the group consisting of alkyl, substituted alkyl, cycloalkyl,
substituted cycloalkyl, a heterocyclic group, a substituted
heterocyclic group, aryl, substituted aryl, heteroaryl, substituted
heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, halogen, formyl,
acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and
sulfonamido, or, alternatively, R.sub.8a, R.sub.8b and R.sub.8c are
each independently a fused cycloalkyl, a substituted fused
cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic,
a fused aryl, a substituted fused aryl, a fused heteroaryl or a
substituted fused heteroaryl ring when substituted for hydrogen
atoms on two adjacent atoms;
[0090] X.sub.3 is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+; [0091]
wherein R.sub.9 is hydrogen, lower alkyl, substituted lower alkyl,
sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen, lower
alkyl, or substituted lower alkyl;
[0092] Z.sub.10 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl; and
[0093] T.sub.3 is the same as defined for T.sub.2 with the
exception that U.sub.a is bonded to X.sub.3 of formula III; or
##STR00007##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof, wherein: [0094] R.sub.100 is cycloalkyl; [0095]
R.sub.102 is selected from the group consisting of lower alkyl and
substituted lower alkyl; [0096] R.sub.103 is selected from the
group consisting of alkyl and alkyl substituted with aryl; [0097]
R.sub.104, R.sub.105, R.sub.106, and R.sub.107 are independently
selected from the group consisting of hydrogen, lower alkyl and
substituted lower alkyl; [0098] R.sub.108 is selected from the
group consisting of hydrogen and lower alkyl; [0099] Y.sub.20 is
selected from the group consisting of O and CR.sub.9aR.sub.9b;
wherein R.sub.9a and R.sub.9b are independently selected from the
group consisting of hydrogen and lower alkyl; [0100] Z.sub.20 is
selected from the group consisting of:
[0100] ##STR00008## [0101] wherein (A) and (Y) indicate the bonds
of Z.sub.20 to CHR.sub.105 and Y.sub.20 of formula IV,
respectively; [0102] L.sub.1, L.sub.2 and L.sub.3 are independently
selected from the group consisting of O, and CR.sub.10aR.sub.10b;
wherein R.sub.10a and R.sub.10b are independently selected from the
group consisting of hydrogen and lower alkyl; [0103] X.sub.100,
X.sub.102, X.sub.103, X.sub.104, X.sub.105, X.sub.106 and X.sub.107
are independently selected from the group consisting of hydrogen,
halogen, trifluoromethyl and lower alkyl; and [0104] m.sub.a is 0
or 1; and n.sub.a is 1 or 2.
[0105] Aspects of the present invention further provide methods of
stimulating gastrointestinal motility and/or treating a
gastrointestinal disorder comprising administering to a subject in
need thereof an effective amount of an agonist for a mammalian
ghrelin receptor. In still other embodiments, the agonist is a
compound of formula I, II, III and/or IV.
[0106] Aspects of the present invention further relate to methods
of preventing and/or treating disorders described herein, in
particular, gastrointestinal disorders, including post-operative
ileus, gastroparesis, such as idiopathic, diabetic and
post-surgical gastroparesis, opioid-induced bowel dysfunction,
chronic intestinal pseudo-obstruction, short bowel syndrome, emesis
such as caused by cancer chemotherapy, constipation such as
associated with the hypomotility phase of irritable bowel syndrome
(IBS), delayed gastric emptying associated with wasting conditions,
gastroesophageal reflux disease (GERD), gastric ulcers, Crohn's
disease, gastrointestinal disorders characterized by dysmotility
and other diseases and disorders of the gastrointestinal tract.
[0107] A further aspect of the invention relates to methods for the
simultaneous treatment of multiple gastrointestinal disorders such
as those listed above, in particular postoperative ileus and
opioid-induced bowel dysfunction as well as post-surgical
gastropareis and opioid-induced bowel dysfunction.
[0108] Another aspect of the invention relates to methods for the
simultaneous treatment of multiple gastrointestinal disorders such
as those listed above that occur concurrently.
[0109] Another aspect of the invention relates to methods for the
simultaneous treatment of multiple gastrointestinal disorders such
as those listed above that occur sequentially.
[0110] The present invention also relates to compounds of formula
I, II, III and/or IV used for the preparation of a medicament for
prevention and/or treatment of the disorders described herein.
Additionally, the present invention provides co-administration
with, administration prior to (including prior to initial therapy),
and administration after administration of an opioid or opioid-like
compound to stimulate gastrointestinal motility as well as for the
prevention and treatment of opioid-induced bowel dysfunction.
[0111] The foregoing and other aspects of the present invention are
explained in greater detail in the specification set forth
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0112] FIG. 1 shows the chemical structures for two exemplary
compounds of the present invention.
[0113] FIG. 2 (panels A and B) shows graphs presenting effects on
gastric emptying for exemplary compounds of the present
invention.
[0114] FIG. 3 shows a graph presenting effects on meal transit in
an animal model of postoperative ileus for an exemplary compound of
the present invention.
[0115] FIG. 4 shows a graph presenting effects on gastric emptying
in an animal model of postoperative ileus for an exemplary compound
of the present invention.
[0116] FIG. 5 shows a graphic representation of the experimental
design for the study of opioid-induced bowel dysfunction.
[0117] FIG. 6 shows a graph presenting effects on gastric emptying
in an animal model of opioid-induced bowel dysfunction for an
exemplary compound of the present invention.
[0118] FIG. 7 shows a graphic representation of the experimental
design for the combination study of post-operative ileus and
opioid-induced bowel dysfunction.
[0119] FIG. 8 shows a graph presenting effects on gastric emptying
in a combination animal model of post-operative ileus and
opioid-induced bowel dysfunction for an exemplary compound of the
present invention.
[0120] FIG. 9 (panels A and B) shows a graph presenting effects on
meal transit in the combination animal model of post-operative
ileus and opioid-induced bowel dysfunction for an exemplary
compound of the present invention.
DETAILED DESCRIPTION
[0121] The foregoing and other aspects of the present invention
will now be described in more detail with respect to other
embodiments described herein. It should be appreciated that the
invention can be embodied in different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0122] The terminology used in the description of the invention
herein is for the purpose of describing particular embodiments only
and is not intended to be limiting of the invention. As used in the
description of the invention and the appended claims, the singular
forms "a", "an" and "the" are intended to include the plural forms
as well, unless the context clearly indicates otherwise.
Additionally, as used herein, the term "and/or" includes any and
all combinations of one or more of the associated listed items and
may be abbreviated as "/".
[0123] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs.
[0124] All publications, U.S. patent applications, U.S. patents and
other references cited herein are incorporated by reference in
their entireties.
[0125] The term "alkyl" refers to straight or branched chain
saturated or partially unsaturated hydrocarbon groups having from 1
to 20 carbon atoms, in some instances 1 to 8 carbon atoms. The term
"lower alkyl" refers to alkyl groups containing 1 to 6 carbon
atoms. Examples of alkyl groups include, but are not limited to,
methyl, ethyl, isopropyl, tert-butyl, 3-hexenyl, and 2-butynyl. By
"unsaturated" is meant the presence of 1, 2 or 3 double or triple
bonds, or a combination of the two. Such alkyl groups may also be
optionally substituted as described below.
[0126] When a subscript is used with reference to an alkyl or other
hydrocarbon group defined herein, the subscript refers to the
number of carbon atoms that the group may contain.
[0127] For example, C.sub.2-C.sub.4 alkyl indicates an alkyl group
with 2, 3 or 4 carbon atoms.
[0128] The term "cycloalkyl" refers to saturated or partially
unsaturated cyclic hydrocarbon groups having from 3 to 15 carbon
atoms in the ring, in some instances 3 to 7, and to alkyl groups
containing said cyclic hydrocarbon groups. Examples of cycloalkyl
groups include, but are not limited to, cyclopropyl,
cyclopropylmethyl, cyclopentyl, 2-(cyclohexyl)ethyl, cycloheptyl,
and cyclohexenyl. Cycloalkyl as defined herein also includes groups
with multiple carbon rings, each of which may be saturated or
partially unsaturated, for example decalinyl,
[2.2.1]-bicycloheptanyl or adamantanyl. All such cycloalkyl groups
may also be optionally substituted as described below.
[0129] The term "aromatic" refers to an unsaturated cyclic
hydrocarbon group having a conjugated pi electron system that
contains 4n+2 electrons where n is an integer greater than or equal
to 1. Aromatic molecules are typically stable and are depicted as a
planar ring of atoms with resonance structures that consist of
alternating double and single bonds, for example benzene or
naphthalene.
[0130] The term "aryl" refers to an aromatic group in a single or
fused carbocyclic ring system having from 6 to 15 ring atoms, in
some instances 6 to 10, and to alkyl groups containing said
aromatic groups. Examples of aryl groups include, but are not
limited to, phenyl, 1-naphthyl, 2-naphthyl and benzyl. Aryl as
defined herein also includes groups with multiple aryl rings which
may be fused, as in naphthyl and anthracenyl, or unfused, as in
biphenyl and terphenyl. Aryl also refers to bicyclic or tricyclic
carbon rings, where one of the rings is aromatic and the others of
which may be saturated, partially unsaturated or aromatic, for
example, indanyl or tetrahydronaphthyl (tetralinyl). All such aryl
groups may also be optionally substituted as described below.
[0131] The term "heterocycle" or "heterocyclic" refers to saturated
or partially unsaturated monocyclic, bicyclic or tricyclic groups
having from 3 to 15 atoms, in some instances 3 to 7, with at least
one heteroatom in at least one of the rings, said heteroatom being
selected from O, S or N. Each ring of the heterocyclic group can
contain one or two O atoms, one or two S atoms, one to four N
atoms, provided that the total number of heteroatoms in each ring
is four or less and each ring contains at least one carbon atom.
The fused rings completing the bicyclic or tricyclic heterocyclic
groups may contain only carbon atoms and may be saturated or
partially unsaturated. The N and S atoms may optionally be oxidized
and the N atoms may optionally be quaternized. Heterocyclic also
refers to alkyl groups containing said monocyclic, bicyclic or
tricyclic heterocyclic groups. Examples of heterocyclic rings
include, but are not limited to, 2- or 3-piperidinyl, 2- or
3-piperazinyl, 2- or 3-morpholinyl.
All such heterocyclic groups may also be optionally substituted as
described below
[0132] The term "heteroaryl" refers to an aromatic group in a
single or fused ring system having from 5 to 15 ring atoms, in some
instances 5 to 10, which have at least one heteroatom in at least
one of the rings, said heteroatom being selected from O, S or N.
Each ring of the heteroaryl group can contain one or two O atoms,
one or two S atoms, one to four N atoms, provided that the total
number of heteroatoms in each ring is four or less and each ring
contains at least one carbon atom. The fused rings completing the
bicyclic or tricyclic groups may contain only carbon atoms and may
be saturated, partially unsaturated or aromatic. In structures
where the lone pair of electrons of a nitrogen atom is not involved
in completing the aromatic pi electron system, the N atoms may
optionally be quaternized or oxidized to the N-oxide. Heteroaryl
also refers to alkyl groups containing said cyclic groups. Examples
of monocyclic heteroaryl groups include, but are not limited to
pyrrolyl, pyrazolyl, pyrazolinyl, imidazolyl, oxazolyl, isoxazolyl,
thiazolyl, thiadiazolyl, isothiazolyl, furanyl, thienyl,
oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and
triazinyl. Examples of bicyclic heteroaryl groups include, but are
not limited to indolyl, benzothiazolyl, benzoxazolyl, benzothienyl,
quinolinyl, tetrahydroisoquinolinyl, isoquinolinyl, benzimidazolyl,
benzopyranyl, indolizinyl, benzofuranyl, isobenzofuranyl,
chromonyl, coumarinyl, benzopyranyl, cinnolinyl, quinoxalinyl,
indazolyl, purinyl, pyrrolopyridinyl, furopyridinyl,
thienopyridinyl, dihydroisoindolyl, and tetrahydroquinolinyl.
Examples of tricyclic heteroaryl groups include, but are not
limited to carbazolyl, benzindolyl, phenanthrollinyl, acridinyl,
phenanthridinyl, and xanthenyl. All such heteroaryl groups may also
be optionally substituted as described below.
[0133] The term "hydroxy" refers to the group --OH.
[0134] The term "alkoxy" refers to the group --OR.sub.a, wherein
R.sub.a is alkyl, cycloalkyl or heterocyclic. Examples include, but
are not limited to methoxy, ethoxy, tert-butoxy, cyclohexyloxy and
tetrahydropyranyloxy.
[0135] The term "aryloxy" refers to the group --OR.sub.b wherein
R.sub.b is aryl or heteroaryl. Examples include, but are not
limited to phenoxy, benzyloxy and 2-naphthyloxy.
[0136] The term "acyl" refers to the group --C(.dbd.O)--R.sub.c
wherein R.sub.c is alkyl, cycloalkyl, heterocyclic, aryl or
heteroaryl. Examples include, but are not limited to, acetyl,
benzoyl and furoyl.
[0137] The twin "amino acyl" indicates an acyl group that is
derived from an amino acid.
[0138] The term "amino" refers to an --NR.sub.dR.sub.e group
wherein R.sub.d and R.sub.e are independently selected from the
group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, aryl
and heteroaryl. Alternatively, R.sub.d and R.sub.e together form a
heterocyclic ring of 3 to 8 members, optionally substituted with
unsubstituted alkyl, unsubstituted cycloalkyl, unsubstituted
heterocyclic, unsubstituted aryl, unsubstituted heteroaryl,
hydroxy, alkoxy, aryloxy, acyl, amino, amido, carboxy,
carboxyalkyl, carboxyaryl, mercapto, sulfinyl, sulfonyl,
sulfonamido, amidino, carbamoyl, guanidino or ureido, and
optionally containing one to three additional heteroatoms selected
from O, S or N.
[0139] The term "amido" refers to the group
--C(.dbd.O)--NR.sub.fR.sub.g wherein R.sub.f and R.sub.g are
independently selected from the group consisting of hydrogen,
alkyl, cycloalkyl, heterocyclic, aryl and heteroaryl.
Alternatively, R.sub.f and R.sub.g together form a heterocyclic
ring of 3 to 8 members, optionally substituted with unsubstituted
alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic,
unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy,
aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl,
mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl,
guanidino or ureido, and optionally containing one to three
additional heteroatoms selected from O, S or N.
[0140] The term "amidino" refers to the group
--C(.dbd.NR.sub.h)NR.sub.iR.sub.j wherein R.sub.h is selected from
the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic,
aryl and heteroaryl; and R.sub.i and R.sub.j are independently
selected from the group consisting of hydrogen, alkyl, cycloalkyl,
heterocyclic, aryl and heteroaryl. Alternatively, R.sub.i and
R.sub.j together form a heterocyclic ring of 3 to 8 members,
optionally substituted with unsubstituted alkyl, unsubstituted
cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl,
unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino,
amido, carboxy, carboxyalkyl, carboxyaryl, mercapto, sulfinyl,
sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or ureido, and
optionally containing one to three additional heteroatoms selected
from O, S or N.
[0141] The term "carboxy" refers to the group --CO.sub.2H.
[0142] The term "carboxyalkyl" refers to the group
--CO.sub.2R.sub.k, wherein R.sub.k is alkyl, cycloalkyl or
heterocyclic.
[0143] The term "carboxyaryl" refers to the group
--CO.sub.2R.sub.m, wherein R.sub.m, is aryl or heteroaryl.
[0144] The term "cyano" refers to the group --CN.
[0145] The term "formyl" refers to the group --C(.dbd.O)H, also
denoted --CHO.
[0146] The term "halo," "halogen" or "halide" refers to fluoro,
fluorine or fluoride, chloro, chlorine or chloride, bromo, bromine
or bromide, and iodo, iodine or iodide, respectively.
[0147] The term "oxo" refers to the bivalent group .dbd.O, which is
substituted in place of two hydrogen atoms on the same carbon to
form a carbonyl group.
[0148] The term "mercapto" refers to the group --SR.sub.n wherein
R.sub.n is hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or
heteroaryl.
[0149] The term "nitro" refers to the group --NO.sub.2.
[0150] The term "trifluoromethyl" refers to the group
--CF.sub.3.
[0151] The term "sulfinyl" refers to the group --S(.dbd.O)R.sub.p
wherein R.sub.p is alkyl, cycloalkyl, heterocyclic, aryl or
heteroaryl.
[0152] The term "sulfonyl" refers to the group
--S(.dbd.O).sub.2--R.sub.q1 wherein R.sub.q1 is alkyl, cycloalkyl,
heterocyclic, aryl or heteroaryl.
[0153] The term "aminosulfonyl" refers to the group
--NR.sub.q2--S(.dbd.O).sub.2--R.sub.q3 wherein R.sub.q2 is
hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl; and
R.sub.q3 is alkyl, cycloalkyl, heterocyclic, aryl or
heteroaryl.
[0154] The term "sulfonamido" refers to the group
--S(.dbd.O).sub.2--NR.sub.rR.sub.s wherein R.sub.r and R.sub.s are
independently selected from the group consisting of hydrogen,
alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Alternatively,
R.sub.r and R.sub.s together form a heterocyclic ring of 3 to 8
members, optionally substituted with unsubstituted alkyl,
unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted
aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl,
amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto,
sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or
ureido, and optionally containing one to three additional
heteroatoms selected from O, S or N.
[0155] The term "carbamoyl" refers to a group of the formula
--N(R.sub.t)--C(.dbd.O)--OR.sub.u wherein R.sub.t is selected from
hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl; and
R.sub.u is selected from alkyl, cycloalkyl, heterocylic, aryl or
heteroaryl.
[0156] The term "guanidino" refers to a group of the formula
--N(R.sub.v)--C(.dbd.NR.sub.w)--NR.sub.xR.sub.y wherein R.sub.v,
R.sub.w, R.sub.x and R.sub.y are independently selected from
hydrogen, alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl.
Alternatively, R.sub.x and R.sub.y together form a heterocyclic
ring or 3 to 8 members, optionally substituted with unsubstituted
alkyl, unsubstituted cycloalkyl, unsubstituted heterocyclic,
unsubstituted aryl, unsubstituted heteroaryl, hydroxy, alkoxy,
aryloxy, acyl, amino, amido, carboxy, carboxyalkyl, carboxyaryl,
mercapto, sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl,
guanidino or ureido, and optionally containing one to three
additional heteroatoms selected from O, S or N.
[0157] The term "ureido" refers to a group of the formula
--N(R.sub.z)--C(.dbd.O)--NR.sub.aaR.sub.bb wherein R.sub.z,
R.sub.aa and R.sub.bb are independently selected from hydrogen,
alkyl, cycloalkyl, heterocyclic, aryl or heteroaryl. Alternatively,
R.sub.aa and R.sub.bb together form a heterocyclic ring of 3 to 8
members, optionally substituted with unsubstituted alkyl,
unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted
aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl,
amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto,
sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or
ureido, and optionally containing one to three additional
heteroatoms selected from O, S or N.
[0158] The term "optionally substituted" is intended to expressly
indicate that the specified group is unsubstituted or substituted
by one or more suitable substituents, unless the optional
substituents are expressly specified, in which case the term
indicates that the group is unsubstituted or substituted with the
specified substituents. As defined above, various groups may be
unsubstituted or substituted (i.e., they are optionally
substituted) unless indicated otherwise herein (e.g., by indicating
that the specified group is unsubstituted).
[0159] The term "substituted" when used with the terms alkyl,
cycloalkyl, heterocyclic, aryl and heteroaryl refers to an alkyl,
cycloalkyl, heterocyclic, aryl or heteroaryl group having one or
more of the hydrogen atoms of the group replaced by substituents
independently selected from unsubstituted alkyl, unsubstituted
cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl,
unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl, amino,
amido, carboxy, carboxyalkyl, carboxyaryl, halo, oxo, mercapto,
sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino,
ureido and groups of the formulas --NR.sub.ccC(.dbd.O)R.sub.dd,
--NR.sub.eeC(.dbd.NR.sub.ff)R.sub.gg,
--OC(.dbd.O)NR.sub.hhR.sub.ii, --OC(.dbd.O)R.sub.jj,
--OC(.dbd.O)OR.sub.kk, --NR.sub.mmSO.sub.2R.sub.nn, or
--NR.sub.ppSO.sub.2NR.sub.qqR.sub.rr wherein R.sub.cc, R.sub.dd,
R.sub.ee, R.sub.ff, R.sub.gg, R.sub.hh, R.sub.ii, R.sub.jj,
R.sub.mm, R.sub.pp, R.sub.qq and R.sub.rr are independently
selected from hydrogen, unsubstituted alkyl, unsubstituted
cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl or
unsubstituted heteroaryl; and wherein R.sub.kk and R.sub.nn are
independently selected from unsubstituted alkyl, unsubstituted
cycloalkyl, unsubstituted heterocyclic, unsubstituted aryl or
unsubstituted heteroaryl. Alternatively, R.sub.gg and R.sub.hh, and
R.sub.kk or R.sub.pp and R.sub.qq together form a heterocyclic ring
of 3 to 8 members, optionally substituted with unsubstituted alkyl,
unsubstituted cycloalkyl, unsubstituted heterocyclic, unsubstituted
aryl, unsubstituted heteroaryl, hydroxy, alkoxy, aryloxy, acyl,
amino, amido, carboxy, carboxyalkyl, carboxyaryl, mercapto,
sulfinyl, sulfonyl, sulfonamido, amidino, carbamoyl, guanidino or
ureido, and optionally containing one to three additional
heteroatoms selected from O, S or N. In addition, the term
"substituted" for aryl and heteroaryl groups includes as an option
having one of the hydrogen atoms of the group replaced by cyano,
nitro or trifluoromethyl.
[0160] A substitution is made provided that any atom's normal
valency is not exceeded and that the substitution results in a
stable compound. Generally, when a substituted form of a group is
present, such substituted group is preferably not further
substituted or, if substituted, the substituent comprises only a
limited number of substituted groups, in some instances 1, 2, 3 or
4 such substituents.
[0161] When any variable occurs more than one time in any
constituent or in any formula herein, its definition on each
occurrence is independent of its definition at every other
occurrence. Also, combinations of substituents and/or variables are
permissible only if such combinations result in stable
compounds.
[0162] A "stable compound" or "stable structure" refers to a
compound that is sufficiently robust to survive isolation to a
useful degree of purity and formulation into an efficacious
therapeutic agent.
[0163] The term "amino acid" refers to the common natural
(genetically encoded) or synthetic amino acids and common
derivatives thereof, known to those skilled in the art. When
applied to amino acids, "standard" or "proteinogenic" refers to the
genetically encoded 20 amino acids in their natural configuration.
Similarly, when applied to amino acids, "unnatural" or "unusual"
refers to the wide selection of non-natural, rare or synthetic
amino acids such as those described by Hunt, S. in Chemistry and
Biochemistry of the Amino Acids, Barrett, G. C., Ed., Chapman and
Hall: New York, 1985.
[0164] The term "residue" with reference to an amino acid or amino
acid derivative refers to a group of the formula:
##STR00009##
wherein R.sub.AA is an amino acid side chain, and n=0, 1 or 2 in
this instance.
[0165] The term "fragment" with respect to a dipeptide, tripeptide
or higher order peptide derivative indicates a group that contains
two, three or more, respectively, amino acid residues.
[0166] The term "amino acid side chain" refers to any side chain
from a standard or unnatural amino acid, and is denoted R.sub.AA.
For example, the side chain of alanine is methyl, the side chain of
valine is isopropyl and the side chain of tryptophan is
3-indolylmethyl.
[0167] The term "agonist" refers to a compound that duplicates at
least some of the effect of the endogenous ligand of a protein,
receptor, enzyme or the like.
[0168] The term "antagonist" refers to a compound that inhibits at
least some of the effect of the endogenous ligand of a protein,
receptor, enzyme or the like.
[0169] The term "growth hormone secretagogue" (GHS) refers to any
exogenously administered compound or agent that directly or
indirectly stimulates or increases the endogenous release of growth
hormone, growth hormone-releasing hormone, or somatostatin in an
animal, in particular, a human. A GHS may be peptidic or
non-peptidic in nature, in some instances, with an agent that can
be administered orally. In some instances, the agent can induce a
pulsatile response.
[0170] The term "modulator" refers to a compound that imparts an
effect on a biological or chemical process or mechanism. For
example, a modulator may increase, facilitate, upregulate,
activate, inhibit, decrease, block, prevent, delay, desensitize,
deactivate, down regulate, or the like, a biological or chemical
process or mechanism. Accordingly, a modulator can be an "agonist"
or an "antagonist." Exemplary biological processes or mechanisms
affected by a modulator include, but are not limited to, receptor
binding and hormone release or secretion. Exemplary chemical
processes or mechanisms affected by a modulator include, but are
not limited to, catalysis and hydrolysis.
[0171] The term "opioid" as used herein refers to compounds that
exhibit opium or morphine-like properties. These compounds may
interact with stereospecific and saturable binding sites in the
brain and other tissues. Pharmacological properties may include
drowsiness, respiratory depression, changes in mood and mental
clouding without a resulting loss of consciousness. The term
"opioid-like" as used herein refers to compounds that are similar
in structure and/or pharmacological profile to known opioid
compounds. Examples of opioid and opioid-like compounds, include
but are not limited to, alfentanil, allylprodine, alphaprodine,
anileridine, asimadoline, benzylmorphine, bezitramide, bremazocine,
buprenorphine, butorphanol, clonitazene, codeine, cyclazocine,
desomorphine, dextromoramide, dextromethorphan, dezocine,
diampromide, diamorphone, dihydrocodeine, dihydromorphine,
dimenoxadol, dimepheptanol, dimethylthiambutene, dioxaphetyl
butyrate, diphenoxylate, dipipanone, eptazocine, ethoheptazine,
ethylmethylthiambutene, ethylmorphine, etonitazene, fedotozine,
fentanyl, funaltrexamine, heroin (diacetylmorphine), hydrocodone,
hydromorphone, hydroxypethidine, isomethadone, ketobemidone,
levallorphan, levomethadyl acetate, levorphanol,
levophenacylmorphan, lofentanil, loperamide, meperidine
(pethidine), meptazinol, metazocine, methadone, metopon, morphine,
morphine-6-glucoronide, morphinan, myrophine, narceine,
nicomorphine, norlevorphanol, normethadone, naltrindole,
nalorphine, naloxone, nalbuphine, nalmefene, naltrexone,
normorphine, norpipanone, opium, oxycodone, oxymorphone,
papaveretum, pentazocine, phenadoxone, phenomorphan, phenazocine,
phenoperidine, piminodine, piritramide, propheptazine, promedol,
properidine, propiram, propoxyphene, remifentanyl, sufentanil,
tilidine, tramadol, trimebutine, and derivatives and analogs
thereof.
[0172] The term "variant" when applied to a receptor is meant to
include dimers, trimers, tetramers, pentamers and other biological
complexes containing multiple components. These components can be
the same or different.
[0173] The term "peptide" refers to a chemical compound comprised
of two or more amino acids covalently bonded together.
[0174] The term "peptidomimetic" refers to a chemical compound
designed to mimic a peptide, but which contains structural
differences through the addition or replacement of one of more
functional groups of the peptide in order to modulate its activity
or other properties, such as solubility, metabolic stability, oral
bioavailability, lipophilicity, permeability, etc. This can include
replacement of the peptide bond, side chain modifications,
truncations, additions of functional groups, etc. When the chemical
structure is not derived from the peptide, but mimics its activity,
it is often referred to as a "non-peptide peptidomimetic."
[0175] The term "peptide bond" refers to the amide
[--C(.dbd.O)--NH--] functionality with which individual amino acids
are typically covalently bonded to each other in a peptide.
[0176] The term "protecting group" refers to any chemical compound
that may be used to prevent a potentially reactive functional
group, such as an amine, a hydroxyl or a carboxyl, on a molecule
from undergoing a chemical reaction while chemical change occurs
elsewhere in the molecule. A number of such protecting groups are
known to those skilled in the art and examples can be found in
"Protective Groups in Organic Synthesis," Theodora W. Greene and
Peter G. Wuts, editors, John Wiley & Sons, New York, 3.sup.rd
edition, 1999 [ISBN 0471160199]. Examples of amino protecting
groups include, but are not limited to, phthalimido,
trichloroacetyl, benzyloxycarbonyl, tert-butoxycarbonyl, and
adamantyloxycarbonyl. In some embodiments, amino protecting groups
are carbamate amino protecting groups, which are defined as an
amino protecting group that when bound to an amino group forms a
carbamate. In other embodiments, amino carbamate protecting groups
are allyloxycarbonyl (Alloc), benzyloxycarbonyl (Cbz),
9-fluorenylmethoxycarbonyl (Fmoc), tert-butoxycarbonyl (Boc) and
.alpha.,.alpha.-dimethyl-3,5-dimethoxybenzyloxycarbonyl (Ddz). For
a recent discussion of newer nitrogen protecting groups:
Theodoridis, G. Tetrahedron 2000, 56, 2339-2358. Examples of
hydroxyl protecting groups include, but are not limited to, acetyl,
tert-butyldimethylsilyl (TBDMS), trityl (Trt), tert-butyl, and
tetrahydropyranyl (THP). Examples of carboxyl protecting groups
include, but are not limited to methyl ester, tert-butyl ester,
benzyl ester, trimethylsilylethyl ester, and 2,2,2-trichloroethyl
ester.
[0177] The term "solid phase chemistry" refers to the conduct of
chemical reactions where one component of the reaction is
covalently bonded to a polymeric material (solid support as defined
below). Reaction methods for performing chemistry on solid phase
have become more widely known and established outside the
traditional fields of peptide and oligonucleotide chemistry.
[0178] The term "solid support," "solid phase" or "resin" refers to
a mechanically and chemically stable polymeric matrix utilized to
conduct solid phase chemistry. This is denoted by "Resin," "P-" or
the following symbol:
##STR00010##
[0179] Examples of appropriate polymer materials include, but are
not limited to, polystyrene, polyethylene, polyethylene glycol,
polyethylene glycol grafted or covalently bonded to polystyrene
(also termed PEG-polystyrene, TentaGel.TM., Rapp, W.; Zhang, L.;
Bayer, E. In Innovations and Persepctives in Solid Phase Synthesis.
Peptides, Polypeptides and Oligonucleotides; Epton, R., Ed.; SPCC
Ltd.: Birmingham, UK; p 205), polyacrylate (CLEAR.TM.),
polyacrylamide, polyurethane, PEGA [polyethyleneglycol
poly(N,N-dimethylacrylamide) co-polymer, Meldal, M. Tetrahedron
Lett. 1992, 33, 3077-3080], cellulose, etc. These materials can
optionally contain additional chemical agents to form cross-linked
bonds to mechanically stabilize the structure, for example
polystyrene cross-linked with divinylbenezene (DVB, usually 0.1-5%,
preferably 0.5-2%). This solid support can include as non-limiting
examples aminomethyl polystyrene, hydroxymethyl polystyrene,
benzhydrylamine polystyrene (BHA), methylbenzhydrylamine (MBHA)
polystyrene, and other polymeric backbones containing free chemical
functional groups, most typically, --NH.sub.2 or --OH, for further
derivatization or reaction. The term is also meant to include
"Ultraresins" with a high proportion ("loading") of these
functional groups such as those prepared from polyethyleneimines
and cross-linking molecules (Barth, M.; Rademann, J. J. Comb. Chem.
2004, 6, 340-349). At the conclusion of the synthesis, resins are
typically discarded, although they have been shown to be able to be
reused such as in Frechet, J. M. J.; Hague, K. E. Tetrahedron Lett.
1975, 16, 3055.
[0180] In general, the materials used as resins are insoluble
polymers, but certain polymers have differential solubility
depending on solvent and can also be employed for solid phase
chemistry. For example, polyethylene glycol can be utilized in this
manner since it is soluble in many organic solvents in which
chemical reactions can be conducted, but it is insoluble in others,
such as diethyl ether. Hence, reactions can be conducted
homogeneously in solution, then the product on the polymer
precipitated through the addition of diethyl ether and processed as
a solid. This has been termed "liquid-phase" chemistry.
[0181] The term "linker" when used in reference to solid phase
chemistry refers to a chemical group that is bonded covalently to a
solid support and is attached between the support and the substrate
typically in order to permit the release (cleavage) of the
substrate from the solid support. However, it can also be used to
impart stability to the bond to the solid support or merely as a
spacer element. Many solid supports are available commercially with
linkers already attached.
[0182] Abbreviations used for amino acids and designation of
peptides follow the rules of the IUPAC-IUB Commission of
Biochemical Nomenclature in J. Biol. Chem. 1972, 247, 977-983. This
document has been updated: Biochem. J., 1984, 219, 345-373; Eur. J.
Biochem., 1984, 138, 9-37; 1985, 152, 1; Internat. J. Pept. Prot.
Res., 1984, 24, following p 84; J. Biol. Chem., 1985, 260, 14-42;
Pure Appl. Chem., 1984, 56, 595-624; Amino Acids and Peptides,
1985, 16, 387-410; and in Biochemical Nomenclature and Related
Documents, 2nd edition, Portland Press, 1992, pp 39-67. Extensions
to the rules were published in the JCBN/NC-IUB Newsletter 1985,
1986, 1989; see Biochemical Nomenclature and Related Documents, 2nd
edition, Portland Press, 1992, pp 68-69.
[0183] The term "effective amount" or "effective" is intended to
designate a dose that causes a relief of symptoms of a disease or
disorder as noted through clinical testing and evaluation, patient
observation, and/or the like, and/or a dose that causes a
detectable change in biological or chemical activity. The
detectable changes may be detected and/or further quantified by one
skilled in the art for the relevant mechanism or process. As is
generally understood in the art, the dosage will vary depending on
the administration routes, symptoms and body weight of the patient
but also depending upon the compound being administered.
[0184] Administration of two or more compounds "in combination"
means that the two compounds are administered closely enough in
time that the presence of one alters the biological effects of the
other. The two compounds can be administered simultaneously
(concurrently) or sequentially. Simultaneous administration can be
carried out by mixing the compounds prior to administration, or by
administering the compounds at the same point in time but at
different anatomic sites or using different routes of
administration. The phrases "concurrent administration",
"administration in combination", "simultaneous administration" or
"administered simultaneously" as used herein, means that the
compounds are administered at the same point in time or immediately
following one another. In the latter case, the two compounds are
administered at times sufficiently close that the results observed
are indistinguishable from those achieved when the compounds are
administered at the same point in time.
[0185] The term "pharmaceutically active metabolite" is intended to
mean a pharmacologically active product produced through metabolism
in the body of a specified compound.
[0186] The term "solvate" is intended to mean a pharmaceutically
acceptable solvate form of a specified compound that retains the
biological effectiveness of such compound. Examples of solvates,
without limitation, include compounds of the invention in
combination with water, isopropanol, ethanol, methanol, DMSO, ethyl
acetate, acetic acid, or ethanolamine.
[0187] The term "simultaneously" or "concurrently" is intended to
mean, when applied to a disease or disorder, that the diseases or
disorders occur at the same point in time for at least some of the
time the subject is suffering from the diseases or disorders, or at
a time that is sufficiently close that the outcome is
indistinguishable from that observed when the diseases or disorders
occur at the same point in time. In either instance, the diseases
or disorders do not necessarily occur during the entire duration of
any other disease or disorder.
[0188] The term "sequentially" is intended to mean, when applied to
a disease or disorder, that the diseases or disorders do not occur
at the same point in time, but occur after the presence of another
disease or disorder wherein the outcome is distinguishable from
that observed when the diseases or disorders occur at the same
point in time.
1. Compounds
[0189] Novel macrocyclic compounds of the present invention include
macrocyclic compounds comprising a building block structure
including a tether component that undergoes cyclization to form the
macrocyclic compound. The building block structure can comprise
amino acids (standard and unnatural), hydroxy acids, hydrazino
acids, aza-amino acids, specialized moieties such as those that
play a role in the introduction of peptide surrogates and
isosteres, and a tether component as described herein. The tether
component can be selected from the following:
##STR00011##
[0190] wherein (Z.sub.2) is the site of a covalent bond of T to
Z.sub.2, and Z.sub.2 is as defined below for formula I, and wherein
(X) is the site of a covalent bond of T to X, and X is as defined
below for formula I; L.sub.7 is --CH.sub.2-- or --O--; U.sub.1 is
--CR.sub.101R.sub.102a-- or --C(.dbd.O)--; R.sub.100a is lower
alkyl; R.sub.101a and R.sub.102a are each independently hydrogen,
lower alkyl or substituted lower alkyl; xx is 2 or 3; yy is 1 or 2;
zz is 1 or 2; and aaa is 0 or 1.
[0191] Macrocyclic compounds of the present invention further
include those of formula I, formula II, formula III and/or formula
IV:
##STR00012##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof,
[0192] wherein:
[0193] R.sub.1 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.1 and R.sub.2 together form a 4-, 5-, 6-, 7- or
8-membered ring, optionally comprising an O, S or N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below, or alternatively R.sub.1 and R.sub.9 together form a
3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as defined below;
[0194] R.sub.2 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.1 and R.sub.2 together form a 4-, 5-, 6-, 7- or
8-membered ring, optionally comprising an O, S or N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below; or alternatively R.sub.2 and R.sub.9 together form a
3-, 4-, 5-, 6- or 7-membered ring, optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as defined below;
[0195] R.sub.3 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.3 and R.sub.4 together form a 3-, 4-, 5-, 6- or
7-membered ring, optionally comprising an O or S atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below, or alternatively, R.sub.3 and R.sub.7 or R.sub.3 and
R.sub.11 together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic
ring, optionally comprising an O, S or additional N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined below;
[0196] R.sub.4 is hydrogen or the side chain of an amino acid, or
alternatively R.sub.4 and R.sub.3 together form a 3-, 4-, 5-, 6- or
7-membered ring, optionally comprising an O or S atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below, or alternatively R.sub.4 and R.sub.7 or R.sub.4 and R.sub.11
together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic ring,
optionally comprising an O, S or additional N atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
below;
[0197] R.sub.5 and R.sub.6 are each independently hydrogen or the
side chain of an amino acid or alternatively R.sub.5 and R.sub.6
together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally
comprising an O, S or N atom in the ring, wherein the ring is
optionally substituted with R.sub.8 as defined below;
[0198] R.sub.7 is hydrogen, lower alkyl, substituted lower alkyl,
cycloalkyl, substituted cycloalkyl, a heterocyclic group, or a
substituted heterocyclic group, or alternatively R.sub.3 and
R.sub.7 or R.sub.4 and R.sub.7 together form a 4-, 5-, 6-, 7- or
8-membered heterocyclic ring optionally comprising an O, S or
additional N atom in the ring, wherein the ring is optionally
substituted with R.sub.8 as described below;
[0199] R.sub.8 is substituted for one or more hydrogen atoms on the
3-, 4-, 5-, 6-, 7- or 8-membered ring structure and is
independently selected from the group consisting of alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, oxo, amino, halogen, formyl, acyl, carboxy,
carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido,
amidino, mercapto, sulfinyl, sulfonyl and sulfonamido, or,
alternatively, R.sub.8 is a fused cycloalkyl, a substituted fused
cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic,
a fused aryl, a substituted fused aryl, a fused heteroaryl or a
substituted fused heteroaryl ring when substituted for hydrogen
atoms on two adjacent atoms;
[0200] X is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+;
[0201] wherein R.sub.9 is hydrogen, lower alkyl, substituted lower
alkyl, sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen,
lower alkyl, or substituted lower alkyl, or alternatively R.sub.9
and
[0202] R.sub.1 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O, S or additional N atom in the ring,
wherein the ring is optionally substituted with R.sub.8 as defined
above;
[0203] Z.sub.1 is O or NR.sub.11,
[0204] wherein R.sub.11 is hydrogen, lower alkyl, or substituted
lower alkyl, or alternatively R.sub.3 and R.sub.11 or R.sub.4 and
R.sub.11 together form a 4-, 5-, 6-, 7- or 8-membered heterocyclic
ring, optionally comprising an O, S or additional N atom in the
ring, wherein the ring is optionally substituted with R.sub.8 as
defined above;
[0205] Z.sub.2 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl;
[0206] m, n and p are each independently 0, 1 or 2;
[0207] T is a bivalent radical of formula V:
--U--(CH.sub.2).sub.d--W--Y--Z--(CH.sub.2).sub.e-- (V)
[0208] wherein d and e are each independently 0, 1, 2, 3, 4 or 5; Y
and Z are each optionally present; U is --CR.sub.21R.sub.22-- or
--C(.dbd.O)-- and is bonded to X of formula I; W, Y and Z are each
independently selected from the group consisting of --O--,
--NR.sub.23--, --S--, --SO--, --SO.sub.2--, --C(.dbd.O)--O--,
--O--C(.dbd.O)--, --C(.dbd.)--NH--, --NH--C(.dbd.O)--,
--SO.sub.2--NH--, --NH--SO.sub.2--, --CR.sub.24R.sub.25--,
--CH.dbd.CH-- with the configuration Z or E, --C.ident.C-- and the
ring structures below:
##STR00013## [0209] or
[0210] wherein G.sub.1 and G.sub.2 are each independently a
covalent bond or a bivalent radical selected from the group
consisting of --O--, --NR.sub.39--, --S--, --SO--, --SO.sub.2--,
--C(.dbd.O)--, --C(.dbd.O)--O--, --O--C(O)--, --C(.dbd.)NH--,
--NH--C(.dbd.O)--, --SO.sub.2--NH--, --NH--SO.sub.2--,
--CR.sub.40R.sub.41--, --CH.dbd.CH-- with the configuration Z or E,
and --C.ident.C--; with G.sub.1 being bonded closest to the group
U; wherein any carbon atom in the rings not otherwise defined, is
optionally replaced by N, with the proviso that the ring cannot
contain more than four N atoms; K.sub.1, K.sub.2, K.sub.3, K.sub.4
and K.sub.5 are each independently O, NR.sub.42 or S, wherein
R.sub.42 is as defined below;
[0211] R.sub.21 and R.sub.22 are each independently hydrogen, lower
alkyl, or substituted lower alkyl, or alternatively R.sub.21 and
R.sub.22 together form a 3- to 12-membered cyclic ring optionally
comprising one or more heteroatoms selected from the group
consisting of O, S and N, wherein the ring is optionally
substituted with R.sub.8 as defined above;
[0212] R.sub.23, R.sub.39 and R.sub.42 are each independently
hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted
cycloalkyl, heterocyclic, substituted heterocyclic, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, formyl, acyl,
carboxyalkyl, carboxyaryl, amido, amidino, sulfonyl or
sulfonamido;
[0213] R.sub.24 and R.sub.25 are each independently hydrogen, lower
alkyl, substituted lower alkyl, R.sub.AA, wherein R.sub.AA is a
side chain of an amino acid such as a standard or unusual amino
acid, or alternatively R.sub.24 and R.sub.25 together form a 3- to
12-membered cyclic ring optionally comprising one or more
heteroatoms selected from the group consisting of O, S and N; or
alternatively one of R.sub.24 or R.sub.25 is hydroxy, alkoxy,
aryloxy, amino, mercapto, carbamoyl, amidino, ureido or guanidino
while the other is hydrogen, lower alkyl or substituted lower
alkyl, except when the carbon to which R.sub.24 and R.sub.25 are
bonded is also bonded to another heteroatom;
[0214] R.sub.26, R.sub.31, R.sub.35 and R.sub.38 are each
optionally present and, when present, are substituted for one or
more hydrogen atoms on the indicated ring and each is independently
selected from the group consisting of halogen, trifluoromethyl,
alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl,
carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano,
nitro, mercapto, sulfinyl, sulfonyl and sulfonamido;
[0215] R.sub.27 is optionally present and is substituted for one or
more hydrogen atoms on the indicated ring and each is independently
selected from the group consisting of alkyl, substituted alkyl,
cycloalkyl, substituted cycloalkyl, a heterocyclic group, a
substituted heterocyclic group, aryl, substituted aryl, heteroaryl,
substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino,
formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and
sulfonamido;
[0216] R.sub.28, R.sub.29, R.sub.30, R.sub.32, R.sub.33, R.sub.34,
R.sub.36 and R.sub.37 are each optionally present and, when no
double bond is present to the carbon atom to which it is bonded in
the ring, two groups are optionally present, and when present, is
substituted for one hydrogen present in the ring, or when no double
bond is present to the carbon atom to which it is bonded in the
ring, is substituted for one or both of the two hydrogen atoms
present on the ring and each is independently selected from the
group consisting of alkyl, substituted alkyl, cycloalkyl,
substituted cycloalkyl, a heterocyclic group, a substituted
heterocyclic group, aryl, substituted aryl, heteroaryl, substituted
heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl,
carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino,
ureido, amidino, mercapto, sulfinyl, sulfonyl, sulfonamido and,
only if a double bond is present to the carbon atom to which it is
bonded, halogen; and
[0217] R.sub.40 and R.sub.41 are each independently hydrogen, lower
alkyl, substituted lower alkyl, R.sub.AA as defined above, or
alternatively R.sub.40 and R.sub.41 together form a 3- to
12-membered cyclic ring optionally comprising one or more
heteroatoms selected from the group consisting of O, S and N
wherein the ring is optionally substituted with R.sub.8 as defined
above, or alternatively one of R.sub.40 and R.sub.41 is hydroxy,
alkoxy, aryloxy, amino, mercapto, carbamoyl, amidino, ureido or
guanidino, while the other is hydrogen, lower alkyl or substituted
lower alkyl, except when the carbon to which R.sub.40 and R.sub.41
are bonded is also bonded to another heteroatom;
[0218] with the proviso that T is not an amino acid residue,
dipeptide fragment, tripeptide fragment or higher order peptide
fragment comprising standard amino acids;
##STR00014##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof, wherein:
[0219] R.sub.50 is --(CH.sub.2).sub.ssCH.sub.3,
--CH(CH.sub.3)(CH.sub.2).sub.ttCH.sub.3,
--(CH.sub.2).sub.uuCH(CH.sub.3).sub.2, --C(CH.sub.3).sub.3,
--(CHR.sub.55).sub.vv--R.sub.56, or --CH(OR.sub.57)CH.sub.3,
wherein ss is 1, 2 or 3; tt is 1 or 2; uu is 0, 1 or 2; and vv is
0, 1, 2, 3 or 4; R.sub.55 is hydrogen or C.sub.1-C.sub.4 alkyl;
R.sub.56 is amino, hydroxy, alkoxy, cycloalkyl or substituted
cycloalkyl; and R.sub.57 is hydrogen, alkyl, acyl, amino acyl,
sulfonyl, carboxyalkyl or carboxyaryl;
[0220] R.sub.51 is hydrogen, C.sub.1-C.sub.4 alkyl or
C.sub.1-C.sub.4 alkyl substituted with hydroxy or alkoxy;
[0221] R.sub.52 is --(CHR.sub.58).sub.wwR.sub.59, wherein ww is 0,
1, 2 or 3; R.sub.58 is hydrogen, C.sub.1-C.sub.4 alkyl, amino,
hydroxy or alkoxy; R.sub.59 is aryl, substituted aryl, heteroaryl,
substituted heteroaryl, cycloalkyl or substituted cycloalkyl;
[0222] R.sub.53 is hydrogen or C.sub.1-C.sub.4 alkyl;
[0223] X.sub.2 is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+; [0224]
wherein R.sub.9 is hydrogen, lower alkyl, substituted lower alkyl,
sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen, lower
alkyl, or substituted lower alkyl;
[0225] Z.sub.5 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl; and
[0226] T.sub.2 is a bivalent radical of formula VI:
--U.sub.a--(CH.sub.2).sub.d--W.sub.a--Y.sub.a--Z.sub.a--(CH.sub.2).sub.e-
-- (VI)
wherein d and e are independently 0, 1, 2, 3, 4 or 5; Y.sub.a and
Z.sub.a are each optionally present; U.sub.a is
--CR.sub.60R.sub.61-- or --C(.dbd.O)-- and is bonded to X.sub.2 of
formula II, wherein R.sub.60 and R.sub.61 are each independently
hydrogen, lower alkyl, or substituted lower alkyl, or alternatively
R.sub.21 and R.sub.22 together form a 3- to 12-membered cyclic ring
optionally comprising one or more heteroatoms selected from the
group consisting of O, S and N, wherein the ring is optionally
substituted with R.sub.8 as defined above; W.sub.a, Y.sub.a and
Z.sub.a are each independently selected from the group consisting
of: --O--, --NR.sub.62--, --S--, --SO--, --SO.sub.2--,
--C(.dbd.O)--O--, --O--C(.dbd.)--, --C(.dbd.))--NH--,
--NH--C(.dbd.O)--, --SO.sub.2--NH--, --NH--SO.sub.2--,
--CR.sub.63R.sub.64--, --CH.dbd.CH-- with the configuration Z or E,
and the ring structures depicted below:
##STR00015##
wherein G.sub.1 and G.sub.2 are as defined above, and wherein any
carbon atom in the ring is optionally replaced by N, with the
proviso that the aromatic ring cannot contain more than four N
atoms and the cycloalkyl ring cannot contain more than two N
atoms;
[0227] R.sub.62 is hydrogen, alkyl, substituted alkyl, cycloalkyl,
substituted cycloalkyl, a heterocyclic group, a substituted
heterocyclic group, aryl, substituted aryl, heteroaryl, substituted
heteroaryl, formyl, acyl, carboxyalkyl, carboxyaryl, amido,
amidino, sulfonyl or sulfonamido;
[0228] R.sub.63 and R.sub.64 are each independently hydrogen, lower
alkyl, substituted lower alkyl or R.sub.AA; or alternatively
R.sub.63 and R.sub.64 together form a 3- to 12-membered cyclic ring
optionally comprising one or more heteroatoms selected from the
group consisting of O, S and N; or alternatively one of R.sub.63
and R.sub.64 is hydroxy, alkoxy, aryloxy, amino, mercapto,
carbamoyl, amidino, ureido or guanidino, while the other is
hydrogen, lower alkyl or substituted lower alkyl, except when the
carbon to which R.sub.63 and R.sub.64 are bonded is also bonded to
another heteroatom; and R.sub.AA indicates the side chain of a
standard or unusual amino acid;
[0229] R.sub.65 and R.sub.68 are each optionally present, and, when
present are substituted for one or more hydrogen atoms on the ring
and each is independently halogen, trifluoromethyl, alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, amino, formyl, acyl, carboxy, carboxyalkyl,
carboxyaryl, amido, carbamoyl, guanidino, ureido, amidino, cyano,
nitro, mercapto, sulfinyl, sulfonyl or sulfonamido;
[0230] R.sub.66 and R.sub.67 are each optionally present, and when
no double bond is present to the carbon atom to which it is bonded
in the ring, two groups are optionally present, and, when present,
each is substituted for one hydrogen present in the ring, or when
no double bond is present to the carbon atom to which it is bonded
in the ring, is substituted for one or both of the two hydrogen
atoms present on the ring and each is independently alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl,
heterocyclic, substituted heterocyclic, aryl, substituted aryl,
heteroaryl, substituted heteroaryl, hydroxy, alkoxy, aryloxy, oxo,
amino, formyl, acyl, carboxy, carboxyalkyl, carboxyaryl, amido,
carbamoyl, guanidino, ureido, amidino, mercapto, sulfinyl,
sulfonyl, sulfonamido and, only if a double bond is present to the
carbon atom to which it is bonded, halogen;
[0231] R.sub.69 is optionally present, and when present is
substituted for one or more hydrogen atoms on the ring and each is
independently alkyl, substituted alkyl, cycloalkyl, substituted
cycloalkyl, a heterocyclic group, a substituted heterocyclic group,
aryl, substituted aryl, heteroaryl, substituted heteroaryl,
hydroxy, alkoxy, aryloxy, oxo, amino, formyl, acyl, carboxy,
carboxyalkyl, carboxyaryl, amido, carbamoyl, guanidino, ureido,
amidino, mercapto, sulfinyl, sulfonyl or sulfonamido; [0232]
K.sub.6 is O or S; and [0233] ff is 1, 2, 3, 4 or 5;
[0234] with the proviso that T.sub.2 is not an amino acid residue,
dipeptide fragment, tripeptide fragment or higher order peptide
fragment comprising standard amino acids; or
##STR00016##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof, wherein:
[0235] R.sub.70 is hydrogen, C.sub.1-C.sub.4 alkyl or alternatively
R.sub.70 and R.sub.71 together form a 4-, 5-, 6-, 7- or 8-membered
ring, optionally comprising an O, N or S atom in the ring, wherein
the ring is optionally substituted with R.sub.8a as defined
below;
[0236] R.sub.71 is hydrogen, --(CH.sub.2).sub.aaCH.sub.3,
--CH(CH.sub.3)(CH.sub.2).sub.bbCH.sub.3,
--(CH.sub.2).sub.ccCH(CH.sub.3).sub.2,
--(CH.sub.2).sub.dd--R.sub.76 or --CH(OR.sub.77)CH.sub.3 or,
alternatively R.sub.71 and R.sub.70 together form a 4-, 5-, 6-, 7-
or 8-membered ring, optionally comprising an O, N or S atom in the
ring, wherein the ring is optionally substituted with R.sub.8a as
defined below; wherein aa is 0, 1, 2, 3, 4 or 5; bb is 1, 2 or 3;
cc is 0, 1, 2 or 3; and dd is 0, 1, 2, 3 or 4; R.sub.76 is aryl,
substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or
substituted cycloalkyl; R.sub.77 is hydrogen, alkyl, acyl, amino
acyl, sulfonyl, carboxyalkyl or carboxyaryl;
[0237] R.sub.72 is C.sub.1-C.sub.4 alkyl; or alternatively R.sub.72
and R.sub.73 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O or S atom in the ring, wherein the ring
is optionally substituted with R.sub.8b as defined below;
[0238] R.sub.73 is hydrogen, or alternatively R.sub.73 and R.sub.72
together form a 3-, 4-, 5-, 6- or 7-membered ring, optionally
comprising an O, S or N atom in the ring, wherein the ring is
optionally substituted with R.sub.8b as defined below;
[0239] R.sub.74 is hydrogen or C.sub.1-C.sub.4 alkyl or
alternatively R.sub.74 and R.sub.75 together form a 3-, 4-, 5-, 6-
or 7-membered ring, optionally comprising an O, N or S atom in the
ring, wherein the ring is optionally substituted with R.sub.8c as
defined below;
[0240] R.sub.75 is --(CHR.sub.78)R.sub.79 or alternatively R.sub.75
and R.sub.74 together form a 3-, 4-, 5-, 6- or 7-membered ring,
optionally comprising an O, N or S atom in the ring, wherein the
ring is optionally substituted with R.sub.8c as defined below;
wherein R.sub.78 is hydrogen, C.sub.1-C.sub.4 alkyl, amino, hydroxy
or alkoxy, and R.sub.79 is selected from the group consisting of
the following structures:
##STR00017##
wherein E.sub.1, E.sub.2, E.sub.3, E.sub.4 and E.sub.5 are each
optionally present and when present are each independently selected
from the group consisting of halogen, trifluoromethyl, alkyl,
substituted alkyl, cycloalkyl, substituted cycloalkyl, a
heterocyclic group, a substituted heterocyclic group, aryl,
substituted aryl, heteroaryl, substituted heteroaryl, hydroxy,
alkoxy, aryloxy, cyano, sulfinyl, sulfonyl and sulfonamido, and
represent substitution at one or more available positions on the
monocyclic or bicyclic aromatic ring, wherein said substitution is
made with the same or different selected group member, and J.sub.1
and J.sub.2 are each independently O or S;
[0241] R.sub.8a, R.sub.8b and R.sub.8c are each independently
substituted for one or more hydrogen atoms on the 3-, 4-, 5-, 6-,
7- or 8-membered ring structure and are independently selected from
the group consisting of alkyl, substituted alkyl, cycloalkyl,
substituted cycloalkyl, a heterocyclic group, a substituted
heterocyclic group, aryl, substituted aryl, heteroaryl, substituted
heteroaryl, hydroxy, alkoxy, aryloxy, oxo, amino, halogen, formyl,
acyl, carboxy, carboxyalkyl, carboxyaryl, amido, carbamoyl,
guanidino, ureido, amidino, mercapto, sulfinyl, sulfonyl and
sulfonamido, or, alternatively, R.sub.8a, R.sub.8b and R.sub.8c are
each independently a fused cycloalkyl, a substituted fused
cycloalkyl, a fused heterocyclic, a substituted fused heterocyclic,
a fused aryl, a substituted fused aryl, a fused heteroaryl or a
substituted fused heteroaryl ring when substituted for hydrogen
atoms on two adjacent atoms;
[0242] X.sub.3 is O, NR.sub.9 or N(R.sub.10).sub.2.sup.+;
[0243] wherein R.sub.9 is hydrogen, lower alkyl, substituted lower
alkyl, sulfonyl, sulfonamido or amidino and R.sub.10 is hydrogen,
lower alkyl, or substituted lower alkyl;
[0244] Z.sub.10 is O or NR.sub.12, wherein R.sub.12 is hydrogen,
lower alkyl, or substituted lower alkyl; and
[0245] T.sub.3 is the same as defined for T.sub.2 with the
exception that U.sub.a is bonded to X.sub.3 of formula III; or
##STR00018##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof wherein: [0246] R.sub.100 is cycloalkyl; [0247]
R.sub.102 is selected from the group consisting of lower alkyl and
substituted lower alkyl; [0248] R.sub.103 is selected from the
group consisting of alkyl and alkyl substituted with aryl; [0249]
R.sub.104, R.sub.105, R.sub.106, and R.sub.107 are independently
selected from the group consisting of hydrogen, lower alkyl and
substituted lower alkyl; [0250] R.sub.108 is selected from the
group consisting of hydrogen and lower alkyl; [0251] Y.sub.20 is
selected from the group consisting of O and CR.sub.9aR.sub.9b;
wherein R.sub.9a and R.sub.9b are independently selected from the
group consisting of hydrogen and lower alkyl; [0252] Z.sub.20 is
selected from the group consisting of:
[0252] ##STR00019## [0253] wherein (A) and (Y) indicate the bonds
of Z.sub.20 to CHR.sub.105 and Y.sub.20 of formula IV,
respectively; [0254] L.sub.1, L.sub.2 and L.sub.3 are independently
selected from the group consisting of O, and CR.sub.10aR.sub.10b;
wherein R.sub.10a and R.sub.10b are independently selected from the
group consisting of hydrogen and lower alkyl; [0255] X.sub.100,
X.sub.102, X.sub.103, X.sub.104, X.sub.105, X.sub.106 and X.sub.107
are independently selected from the group consisting of hydrogen,
halogen, trifluoromethyl and lower alkyl; and [0256] m.sub.a is 0
or 1; and n.sub.a is 1 or 2.
[0257] In some embodiments, when the macrocytic compound has the
structure of formula IV, R.sub.100 is cyclopropyl or cyclohexyl. In
some embodiments, R.sub.102 and R.sub.108 are each methyl. In other
embodiments, R.sub.103 is --CH.sub.2CH(CH.sub.3).sub.2 or
--CHR.sub.110R.sub.120, wherein R.sub.110 is hydrogen or methyl and
R.sub.120 is selected from the group consisting of
##STR00020##
In still other embodiments, Z.sub.20 is selected from the group
consisting of:
##STR00021##
wherein (A) and (Y) indicate the bonds of Z.sub.20 to CHR.sub.105
and Y.sub.20 of formula IV, respectively. According to still other
embodiments, where R.sub.104 and R.sub.106 are hydrogen and
R.sub.105 and R.sub.107 are methyl, Y is CH.sub.2 and Z.sub.20
is
##STR00022##
wherein (A) and (Y) indicate the bonds of Z.sub.20 to CHR.sub.105
and Y.sub.20 of formula IV, respectively. In some embodiments,
where R.sub.104, R.sub.105, R.sub.106 and R.sub.107 are hydrogen,
Y.sub.20 is CH.sub.2 and Z.sub.20 is
##STR00023##
wherein (A) and (Y) indicate the bonds of Z.sub.20 to CHR.sub.105
and Y.sub.20 of formula IV, respectively. In some embodiments,
where R.sub.104, R.sub.105, R.sub.106 and R.sub.107 are hydrogen,
Y.sub.20 is CH.sub.2 and Z.sub.20 is
##STR00024##
wherein (A) and (Y) indicate the bonds of Z.sub.20 to CHR.sub.105
and Y.sub.20 of formula I, respectively. According to some
embodiments, wherein R.sub.104, R.sub.106 and R.sub.107 are
hydrogen, R.sub.105 is methyl, Y.sub.20 is CH.sub.2 and Z.sub.20
is
##STR00025##
wherein (A) and (Y) indicate the bonds of Z.sub.20 to CHR.sub.105
and Y.sub.20 of formula IV, respectively.
[0258] In some embodiments of the present invention, the compound
can have one of the following structures:
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
##STR00031## ##STR00032##
or a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof.
[0259] In other embodiments, the compound can have one of the
following structures:
##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037##
##STR00038## ##STR00039## ##STR00040##
a pharmaceutically acceptable salt, hydrate, solvate, optical
isomer, enantiomer, diastereomer, racemate or stereochemical
mixture thereof.
[0260] The present invention includes isolated compounds. An
isolated compound refers to a compound that, in some embodiments,
comprises at least 10%, at least 25%, at least 50% or at least 70%
of the compounds of a mixture. In some embodiments, the compound,
pharmaceutically acceptable salt thereof or pharmaceutical
composition containing the compound exhibits a statistically
significant binding and/or antagonist activity when tested in
biological assays at the human ghrelin receptor.
[0261] In the case of compounds, salts, or solvates that are
solids, it is understood by those skilled in the art that the
inventive compounds, salts, and solvates may exist in different
crystal or polymorphic forms, all of which are intended to be
within the scope of the present invention and specified
formulas.
[0262] The compounds of formula I, II, III and/or IV disclosed
herein have asymmetric centers. The inventive compounds may exist
as single stereoisomers, racemates, and/or mixtures of enantiomers
and/or diastereomers. All such single stereoisomers, racemates, and
mixtures thereof are intended to be within the scope of the present
invention. In particular embodiments, however, the inventive
compounds are used in optically pure form. The terms "S" and "R"
configuration as used herein are as defined by the IUPAC 1974
Recommendations for Section E, Fundamentals of Stereochemistry
(Pure Appl. Chem. 1976, 45, 13-30.)
[0263] Unless otherwise depicted to be a specific orientation, the
present invention accounts for all stereoisomeric forms. The
compounds may be prepared as a single stereoisomer or a mixture of
stereoisomers. The non-racemic forms may be obtained by either
synthesis or resolution. The compounds may, for example, be
resolved into the component enantiomers by standard techniques, for
example formation of diastereomeric pairs via salt formation. The
compounds also may be resolved by covalently bonding to a chiral
moiety. The diastereomers can then be resolved by chromatographic
separation and/or crystallographic separation. In the case of a
chiral auxiliary moiety, it can then be removed. As an alternative,
the compounds can be resolved through the use of chiral
chromatography. Enzymatic methods of resolution could also be used
in certain cases.
[0264] As generally understood by those skilled in the art, an
"optically pure" compound is one that contains only a single
enantiomer. As used herein, the term "optically active" is intended
to mean a compound comprising at least a sufficient excess of one
enantiomer over the other such that the mixture rotates plane
polarized light. Optically active compounds have the ability to
rotate the plane of polarized light. The excess of one enantiomer
over another is typically expressed as enantiomeric excess (e.e.).
In describing an optically active compound, the prefixes D and L or
R and S are used to denote the absolute configuration of the
molecule about its chiral center(s). The prefixes "d" and "l" or
(+) and (-) are used to denote the optical rotation of the compound
(i.e., the direction in which a plane of polarized light is rotated
by the optically active compound). The "l" or (-) prefix indicates
that the compound is levorotatory (i.e., rotates the plane of
polarized light to the left or counterclockwise) while the "d" or
(+) prefix means that the compound is dextrarotatory (i.e., rotates
the plane of polarized light to the right or clockwise). The sign
of optical rotation, (-) and (+), is not related to the absolute
configuration of the molecule, R and S.
[0265] A compound of the invention having the desired
pharmacological properties will be optically active and, can be
comprised of at least 90% (80% e.e.), at least 95% (90% e.e.), at
least 97.5% (95% e.e.) or at least 99% (98% e.e.) of a single
isomer.
[0266] Likewise, many geometric isomers of double bonds and the
like can also be present in the compounds disclosed herein, and all
such stable isomers are included within the present invention
unless otherwise specified. Also included in the invention are
tautomers and rotamers of formula I, II, III and/or IV.
[0267] The use of the following symbols at the right refers to
substitution of one or more hydrogen atoms of the indicated ring
with the defined substituent R.
##STR00041##
[0268] The use of the following symbol indicates a single bond or
an optional double bond: ------.
2. Synthetic Methods
[0269] The compounds of formula I, II, III and/or IV can be
synthesized using traditional solution synthesis techniques or
solid phase chemistry methods. Synthetic methods for this general
type of macrocyclic structure are described in Intl. Pat. Appls. WO
01/25257, WO 2004/111077, WO 2005/012331, WO 2005/012332, WO
2006/009645 and WO 2006/009674 including purification procedures
described in WO 2004/111077 and WO 2005/012331. The syntheses of
exemplary compound 25 and exemplary compound 298 are provided in WO
2006/009645 and WO 2006/009674. The structures of these compounds
are shown in FIG. 1.
3. Biological Methods
[0270] The compounds of the present invention were evaluated for
their ability to interact at the human ghrelin receptor utilizing a
competitive radioligand binding assay, fluorescence assay or
Aequorin functional assay as described below. Such methods can be
conducted in a high throughput manner to permit the simultaneous
evaluation of many compounds.
[0271] Specific assay methods for the human (GHS-R1a), swine and
rat GHS-receptors (U.S. Pat. No. 6,242,199, Intl. Pat. Appl. Nos.
WO 97/21730 and 97/22004), as well as the canine GHS-receptor (U.S.
Pat. No. 6,645,726), and their use in generally identifying
agonists and antagonists thereof are known.
[0272] Appropriate methods for determining the functional activity
of compounds of the present invention that interact at the human
ghrelin receptor are also described below.
A. Competitive Radioligand Binding Assay (Ghrelin Receptor)
[0273] The competitive binding assay at the human ghrelin receptor
(growth hormone secretagogue receptor, hGHS-R1a) was carried out
analogously to assays described in the literature. (Bednarek M A et
al. Structure-function studies on the new growth hormone-releasing
peptide ghrelin: minimal sequence of ghrelin necessary for
activation of growth hormone secretagogue receptor 1a; J. Med.
Chem. 2000, 43, 4370-4376; Palucki, B. L. et al.
Spiro(indoline-3,4'-piperidine) growth hormone secretagogues as
ghrelin mimetics; Bioorg. Med. Chem. Lett. 2002, 11,
1955-1957.)
Materials
[0274] Membranes (GHS-R/HEK 293) were prepared from HEK-293 cells
stably transfected with the human ghrelin receptor (hGHS-R1a).
These membranes were provided by PerkinElmer BioSignal (#RBHGHSM)
and utilized at a quantity of 0.71 .mu.g/assay point. [0275] 1.
[.sup.125I]-Ghrelin (PerkinElmer, #NEX-388); final concentration:
0.0070-0.0085 nM [0276] 2. Ghrelin (Bachem, #H-4864); final
concentration: 1 .mu.M [0277] 3. Multiscreen Harvest plates-GF/C
(Millipore, #MAHFC1H60) [0278] 4. Deep-well polypropylene titer
plate (Beckman Coulter, #267006) [0279] 5. TopSeal-A (PerkinElmer,
#6005185) [0280] 6. Bottom seal (Millipore, #MATAH0P00) [0281] 7.
MicroScint-0 (PerkinElmer, #6013611) [0282] 8. Binding Buffer: 25
mM Hepes (pH 7.4), 1 mM CaCl.sub.2, 5 mM MgCl.sub.2, 2.5 mM EDTA,
0.4% BSA
Assay Volumes
[0283] Competition experiments were performed in a 300 .mu.l
filtration assay format. [0284] 1. 220 .mu.L of membranes diluted
in binding buffer [0285] 2. 40 .mu.L of compound diluted in binding
buffer [0286] 3. 40 .mu.L of radioligand ([.sup.125I]-Ghrelin)
diluted in binding buffer Final test concentrations (N=1) for
compounds of the present invention: 10, 1, 0.5, 0.2, 0.1, 0.05,
0.02, 0.01, 0.005, 0.002, 0.001
Compound Handling
[0287] Compounds were provided frozen on dry ice at a stock
concentration of 10 mM diluted in 100% DMSO and stored at
-80.degree. C. until the day of testing. On the test day, compounds
were allowed to thaw at rt O/N and then diluted in assay buffer
according to the desired test concentrations. Under these
conditions, the maximal final DMSO concentration in the assay was
0.1%.
Assay Protocol
[0288] In deep-well plates, 220 .mu.L of diluted cell membranes
(final concentration: 0.71 .mu.g/well) were combined with 40 .mu.L
of either binding buffer (total binding, N=5), 1 .mu.M ghrelin
(non-specific binding, N=3) or the appropriate concentration of
test compound (N 2 for each test concentration). The reaction was
initiated by addition of 40 .mu.L of [.sup.125I]-ghrelin (final
conc. 0.0070-0.0085 nM) to each well. Plates were sealed with
TopSeal-A, vortexed gently and incubated at rt for 30 min. The
reaction was arrested by filtering samples through Multiscreen
Harvest plates (pre-soaked in 0.5% polyethyleneimine) using a
Tomtec Harvester, washed 9 times with 500 .mu.L of cold 50 mM
Tris-HCl (pH 7.4, 4.degree. C.), and then plates were air-dried in
a fumehood for 30 min. A bottom seal was applied to the plates
prior to the addition of 25 .mu.L of MicroScint-0 to each well.
Plates were than sealed with TopSeal-A and counted for 30 sec per
well on a TopCount Microplate Scintillation and Luminescence
Counter (PerkinElmer) using a count delay of 60 sec. Results were
expressed as counts per minute (cpm).
[0289] Data were analyzed by GraphPad Prism (GraphPad Software, San
Diego, Calif.) using a variable slope non-linear regression
analysis. K.sub.i values were calculated using a IQ value of 0.01
nM for [.sup.125I]-ghrelin (previously determined during membrane
characterization).
D.sub.max values were calculated using the following formula:
D.sub.max=1-test concentration with maximal
displacement-non-specific binding/total binding-non-specific
binding.times.100
where total and non-specific binding represent the cpm obtained in
the absence or presence of 1 .mu.M ghrelin, respectively.
B. Aequorin Functional Assay (Ghrelin Receptor)
[0290] The functional activity of compounds found to bind to the
ghrelin (GHS-R1a) receptor can be determined using the method
described below which can also be used as a primary screen for
ghrelin receptor activity in a high throughput fashion. (U.S. Pat.
No. 6,872,538; Intl. Pat. Appl. No. WO 00/002045; LePoul, E.; et
al. Adaptation of aequorin functional assay to high throughput
screening. J. Biomol. Screen. 2002, 7, 57-65; Bednarek, M. A.; et
al. Structure-function studies on the new growth hormone-releasing
peptide ghrelin: minimal sequence of ghrelin necessary for
activation of growth hormone secretagogue receptor 1a. J. Med.
Chem. 2000, 43, 4370-4376; Palucki, B. L.; et al.
Spiro(indoline-3,4'-piperidine) growth hormone secretagogues as
ghrelin mimetics. Bioorg. Med, Chem. Lett. 2001, 11,
1955-1957.)
Materials
[0291] Membranes were prepared using AequoScreen.TM. (EUROSCREEN,
Belgium) cell lines expressing the human ghrelin receptor (cell
line ES-410-A; receptor accession #60179). This cell line is
typically constructed by transfection of the human ghrelin receptor
into CHO-K1 cells co-expressing G.sub.a16 and the mitochondrially
targeted Aequorin (Ref #ES-WT-A5). [0292] 1. Ghrelin (reference
agonist; Bachem, #H-4864) [0293] 2. Assay buffer: DMEM (Dulbecco's
Modified Eagles Medium) containing 0.1% BSA (bovine serum albumin;
pH 7.0). [0294] 3. Coelenterazine (Molecular Probes, Leiden, The
Netherlands). Test concentrations (N=8) for compounds of the
invention:
10, 1, 0.3, 0.1, 0.03, 0.01, 0.003, 0.001 .mu.M,
Compound Handling
[0295] Stock solutions of compounds (10 mM in 100% DMSO) were
provided frozen on dry ice and stored at -20.degree. C. prior to
use. From the stock solution, mother solutions were made at a
concentration of 500 .mu.M by 20-fold dilution in 26% DMSO. Assay
plates were then prepared by appropriate dilution in DMEM medium
containing 0.1% BSA. Under these conditions, the maximal final DMSO
concentration in the assay was <0.6%.
Cell Preparation
[0296] AequoScreen.TM. cells were collected from culture plates
with Ca.sup.2+ and Mg.sup.2+-free phosphate buffered saline (PBS)
supplemented with 5 mM EDTA, pelleted for 2 min at 1000.times.g,
re-suspended in DMEM--Ham's F12 containing 0.1% BSA at a density of
5.times.10.sup.6 cells/mL, and incubated O/N at rt in the presence
of 5 .mu.M coelenterazine. After loading, cells were diluted with
assay buffer to a concentration of 5.times.10.sup.5 cells/mL.
Assay Protocol
[0297] For agonist testing, 50 .mu.L of the cell suspension was
mixed with 50 .mu.L of the appropriate concentration of test
compound or ghrelin (reference agonist) in 96-well plates
(duplicate samples). Ghrelin (reference agonist) was tested at
several concentrations concurrently with the test compounds in
order to validate the experiment. The emission of light resulting
from receptor activation in response to ghrelin or test compounds
was recorded using the Hamamatsu FDSS 6000 reader (Hamamatsu
Photonics K. K., Japan).
Analysis and Expression of Results
[0298] Results were expressed as Relative Light Units (RLU).
Concentration response curves were analyzed using GraphPad Prism
(GraphPad Software, San Diego, Calif.) by non-linear regression
analysis (sigmoidal dose-response) based on the equation
E=E.sub.max/(1+EC.sub.50/C)n where E was the measured RLU value at
a given agonist concentration (C), E.sub.max was the maximal
response, EC.sub.50 was the concentration producing 50% stimulation
and n was the slope index. For agonist testing, results for each
concentration of test compound were expressed as percent activation
relative to the signal induced by ghrelin at a concentration equal
to the EC.sub.80 (i.e. 3.7 nM). EC.sub.50, Hill slope and %
E.sub.max values are reported.
[0299] The results obtained show that the representative compounds
examined act as agonists at the ghrelin receptor and are devoid of
antagonist activity at the concentrations studied. In addition,
these compounds were demonstrated to have high selectivity for the
ghrelin receptor versus its closest counterpart, the motilin
receptor, with which it has 52% sequence homology. (Feighner, S.
D.; Tan, C. P.; McKee, K. K.; Palyha, O. C.; Hreniuk, D. L.; Pong,
S.-S.; Austin, C. P.; Figueroa, D.; MacNeil, D.; Cascieri, M. A.;
Nargund, R.; Bakshi, R.; Abramovitz, M.; Stocco, R.; Kargman, S.;
O'Neill, G.; van der Ploeg, L. H. T.; Evans, J.; Patchett, A. A.;
Smith, R. G.; Howard, A. D. Receptor for motilin identified in the
human gastrointestinal system. Science 1999, 284, 2184-2188.) The
endogenous peptides themselves have 36% of residues in common and
ghrelin was even identified at one point as motilin-related
peptide. (Tomasetto, C.; Karam, S. M.; Ribieras, S.; Masson, R.;
Lefebvre, O.; Staub, A.; Alexander, G.; Chenard, M. P.; Rio, M. C.
Identification and characterization of a novel gastric peptide
hormone: the motilin-related peptide. Gastroenterology 2000, 119,
395-405.) Ghrelin does not interact appreciably at the motilin
receptor, although GHRP-6 does. (Depoortere, I.; Thijs, T.;
Thielemans, L.; Robberecht, P.; Peeters, T. L. Interaction of the
growth hormone-releasing peptides ghrelin and growth
hormone-releasing peptide-6 with the motilin receptor in the rabbit
gastric antrum. J. Pharmacol. Exp. Ther. 2003, 305, 660-667.) On
the other hand, motilin itself as been demonstrated to have some
GH-releasing effects. (Samson, W. K.; Lumpkin, M. D.; Nilayer, G.;
McCann, S. M. Motilin: a novel growth hormone releasing agent.
Brain Res. Bull. 1984, 12, 57-62.)
[0300] A wider evaluation of receptor selectivity can be obtained
through the use of "ExpresSProfile", a broad target screen offered
commercially by CEREP (Poitiers, France). In this screen, a
single-point (10 .mu.M) binding assay is performed across 50
individual receptors from four distinct target classes: non-peptide
G-Protein Coupled Receptors (GPCRs), peptide GPCRs, ion channels
and amine transporters.
C. Cell Culture Assay for Growth Hormone Release
[0301] Cell culture assays for determining growth hormone release
can be employed as described in Cheng, et al. Endocrinology 1989,
124, 2791-2798. In particular, anterior pituitary glands are
obtained from male Sprague-Dawley rats and placed in cold culture
medium. These pituitaries are sectioned, for example into
one-eighth sections, then digested with trypsin. Cells are
collected after digestion, pooled, and transferred into 24 well
plates (minimum 200,000 cells per well). After a monolayer of cells
has formed, generally after at least 4 d in culture, the cells are
washed with medium prior to exposure to the test samples and
controls. Varying concentrations of the test compounds and of
ghrelin as a positive control were added to the medium. The cells
are left for 15 min at 37.degree. C., then the medium removed and
the cells stored frozen. The amount of GH release was measured
utilizing a standard radioimmunoassay as known to those in the
art.
D. Gastric Emptying
[0302] A variety of methods and animal models can be used to
investigate the effects of the test compounds on gastric emptying.
(Fukuda, H.; Mizuta, Y.; Isomoto, H.; Takeshima, F.; Ohnita, K.;
Ohba, K.; Omagari, K.; Taniyama, K.; Kohno, S. Ghrelin enhances
gastric motility through direct stimulation of intrinsic neural
pathways and capsaic insensitive afferent neurones in rats. Scand.
J. Gastroenterol. 2004, 39, 1209-1214; Edholm, T.; Levin, F.;
Hellstrom, P. M.; Schmidt, P. T. Ghrelin stimulates motility in the
small intestine of rats through intrinsic cholinergic neurons.
Regul. Pept. 2004, 121, 25-30; Levin, F.; Edholm, T.; Ehrstroem,
M.; Wallin, B.; Schmidt, P. T.; Kirchgessner, A. M.; Hilsted, L.
M.; Hellstrom, P. M.; Naeslund, E. Effect of peripherally
administered ghrelin on gastric emptying and acid secretion in the
rat. Regul. Pept. 2005, 131, 59-65; Tebbe, J. J.; Mronga, S.;
Tebbe, C. G.; Ortmann, E.; Arnold, R.; Schaefer, M. K.-H.
Ghrelin-induced stimulation of colonic propulsion is dependent on
hypothalamic neuropeptide Y1- and corticotropin-releasing factor 1
receptor activation. J. Neuroendocrinol. 2005, 17, 570-576; Bassil,
A. K.; Dass, N. B.; Murray, C. D.; Muir, A.; Sanger, G. J.
Prokineticin-2, motilin, ghrelin and metoclopramide: prokinetic
utility in mouse stomach and colon. Eur. J. Pharmacol. 2005, 524,
138-144; Depoortere, I.; DeWinter, B.; Thijs, T.; DeMan, J.;
Pelckmans, P.; Peeters, T. Comparison of the gastroprokinetic
effects of ghrelin, GHRP-6 and motilin in rats in vivo and in
vitro. Eur. J. Pharmacol. 2005, 515, 160-168.)
[0303] To examine the effects of compounds of the invention in a
model for gastroparesis, compounds were evaluated for possible
effects on gastric emptying in fasted rats as described below.
Test Substances and Dosing Pattern
[0304] GHRP-6 and test samples were dissolved in vehicle of 9%
HPBCD/0.9% NaCl. Immediately following oral administration of
methylcellulose (2%) containing phenol red (0.05%) (2 mL/rat), test
substances or vehicle (9% HPBCD/0.9% NaCl) were each administered
intravenously (i.v.) at a dosing volume of 5 mL/kg.
Animals
[0305] Male Wistar rats were provided by LASCO (A Charles River
Licensee Corporation, Taiwan). Space allocation for 6 animals was
45.times.23.times.15 cm. Animals were housed in APEC.RTM. cages and
maintained in a controlled temperature (22.degree. C.-24.degree.
C.) and humidity (60%-80%) environment with 12 h light, 12 h dark
cycles for at least one week in the laboratory prior to being used.
Free access to standard lab chow for rats (Lab Diet, Rodent Diet,
PMI Nutrition International, USA) and tap water was granted. All
aspects of this work including housing, experimentation and
disposal of animals were performed in general accordance with the
Guide for the Care and Use of Laboratory Animals (National Academy
Press, Washington, D.C., 1996).
Chemicals
[0306] Glucose (Sigma, USA), Metoclopramide-HCl (Sigma, USA),
Methylcellulose (Sigma, USA), NaOH (Sodium Hydroxide, Wako, Japan),
Pyrogen free saline (Astar, Taiwan), Phenol Red-Sodium salt (Sigma,
USA) and Trichloroacetic acid (Merck, USA).
Equipment
[0307] 8-well strip (Costar, USA), 96-well plate (Costar, USA),
Animal case (ShinTeh, R. O. C.), Centrifugal separator (Kokusan,
H-107, Japan), Glass syringe (1 mL, 2 mL, Mitsuba, Japan),
Hypodermic needle (25 G.times.1'', TOP Corporation, Japan),
Microtube (Treff, Switzerland), pH-meter (Hanna, USA), Pipetman
(P100, Gilson, France), Pipette tips (Costar, USA), Rat oral needle
(Natsume, Japan), Spectra Fluor plus (Austria), Stainless scissors
(Klappencker, Germany) and Stainless forceps (Klappencker,
Germany).
Assay
[0308] Test substances were each administered intravenously to a
group of 5 O/N-fasted Wistar derived male rats weighing 200.+-.20 g
immediately after methylcellulose (2%) containing phenol red
(0.05%) was administered orally at 2 mL/animal. The animals were
then sacrificed 15 minutes later. The stomach was immediately
removed, homogenized in 0.1 N NaOH (5 mL) and centrifuged.
Following protein precipitation by 20% trichloroacetic acid (0.5
mL) and re-alkalization of the supernatant with 0.1 N NaOH, total
phenol red remaining in the stomach was determined by a
colorimetric method at 560 nm. A 30 percent or more (.gtoreq.30%)
increase in gastric emptying, detected as the decrease in phenol
red concentration in the stomach relative to the vehicle control
group, is considered significant. Results for two representative
compounds of the invention are shown in FIG. 2 and presented in the
Examples below.
E. Gastric Emptying and Intestinal Transit in Rat Model of
Postoperative Ileus
[0309] This clinically relevant model for POI is adapted from that
of Kalff. (Kalff, J. C.; Schraut, W. H.; Simmons, R. L.; Bauer, A.
J. Surgical manipulation of the gut elicits an intestinal
muscularis inflammatory response resulting in postsurgical ileus.
Ann. Surg. 1998, 228, 652-663.) Other known models can also be used
to study the effect of compounds of the invention. (Trudel, L.;
Bouin, M.; Tomasetto, C.; Eberling, P.; St-Pierre, S.; Bannon, P.;
L'Heureux, M. C.; Poitras, P. Two new peptides to improve
post-operative gastric ileus in dog. Peptides 2003, 24, 531-534;
Trudel, L.; Tomasetto, C.; Rio, M. C.; Bouin, M.; Plourde, V.;
Eberling, P.; Poitras, P. Ghrelin/motilin-related peptide is a
potent prokinetic to reverse gastric postoperative ileus in rats.
Am. J. Physiol. 2002, 282, G948-G952.)
Animals
[0310] 1. Rat, Sprague-Dawley, male, .about.300 g. [0311] 2. Fasted
0/N prior to study.
Induction of Post-Operative Ileus (POI)
[0311] [0312] 1. Isofluorane anaesthesia under sterile conditions.
[0313] 2. Midline abdominal incision. [0314] 3. Intestines and
caecum were eviscerated and kept moist with saline. [0315] 4. The
intestines and caecum were manipulated along its entire length with
moist cotton applicators analogous to the `running of the bowel` in
the clinical setting. This procedure was timed to last for 10 min.
[0316] 5. Intestines were gently replaced into the abdomen and the
abdominal wound was stitched closed under sterile conditions.
Dosing
[0316] [0317] 1. Rat was allowed to recover from isofluorane
anaesthesia. [0318] 2. Test compounds (or vehicle) were
administered intravenously via previously implanted jugular
catheter. [0319] 3. Immediate intragastric gavage of
methylcellulose (2%) labeled with radioactive .sup.99mTc, t=0.
Experimental
[0319] [0320] 1. At t=15 min, animal was euthanized with CO.sub.2.
[0321] 2. Stomach and 10 cm sections along the small intestine were
immediately ligated, cut and placed in tubes for measuring of
.sup.99mTc in gamma counter. [0322] 3. Stomach emptying and small
intestinal transit were measured by calculation of the geometric
mean.
[0322] Geometric mean=.SIGMA.(% total radioactivity.times.number of
segment)/100
[0323] Results for a representative compound of the invention are
depicted in the graph in FIGS. 3 and 4. Further results are
presented in the Examples below.
F. Growth Hormone Response to Test Compounds
[0324] The compounds of the invention likewise can be tested in a
number of animal models for their effect on GH release. For
example, rats (Bowers, C. Y.; Momany, F.; Reynolds, G. A.; Chang,
D.; Hong, A.; Chang, K. Endocrinology 1980, 106, 663-667), dogs
(Hickey, G.; Jacks, T.; Judith, F.; Taylor, J.; Schoen, W. R.;
Krupa, D.; Cunningham, P.; Clark, J.; Smith, R. G. Endocrinology
1994, 134, 695-701; Jacks, T.; Hickey, G.; Judith, F.; Taylor, J.;
Chen, H.; Krupa, D.; Feeney, W.; Schoen, W. R.; Ok, D.; Fisher, M.;
Wyvratt, M.; Smith, R. J. Endocrinology 1994, 143, 399-406; Hickey,
G. J.; Jacks, T. M.; Schleim, K. D.; Frazier, E.; Chen, H. Y.;
Krupa, D.; Feeney, W.; Nargund, R. P.; Patchett, A. A.; Smith, R.
G. J. Endocrinol. 1997, 152, 183-192), and pigs (Chang, C. H.;
Rickes, E. L.; Marsilio, F.; McGuire, L.; Cosgrove, S.; Taylor, J.;
Chen, H. Y.; Feighner, S.; Clark, J. N.; Devita, R.; Schoen, W. R.;
Wyvratt, M.; Fisher, M.; Smith, R. G.; Hickey, G. Endocrinology
1995, 136, 1065-1071; Peschke, B.; Hanse, B. S. Bioorg. Med. Chem.
Lett. 1999, 9, 1295-1298) have all been successfully utilized for
the in vivo study of the effects of GHS and would likewise be
applicable for investigation of the effect of ghrelin agonists on
GH levels. The measurement of ghrelin of GH levels in plasma after
appropriate administration of compounds of the invention can be
performed using radioimmunoassay via standard methods known to
those in the art. (Deghenghi, R.; et al. Life Sciences 1994, 54,
1321-1328.) Binding to tissue can be studied using whole body
autoradiography after dosing of an animal with test substance
containing a radioactive label. (Ahnfelt-Ronne, I.; Nowak, J.;
Olsen, U. B. Do growth hormone-releasing peptides act as ghrelin
secretagogues? Endocrine 2001, 14, 133-135.)
[0325] The following method is employed to determine the temporal
pattern and magnitude of the growth hormone (GH) response to test
compounds, administered either systemically or centrally.
Dosing and Sampling Procedures for In Vivo Studies of GH
Release
[0326] Adult male Sprague Dawley rats (225-300 g) were purchased
from Charles River Canada (St. Constant, Canada) and individually
housed on a 12-h light, 12-h dark cycle (lights on, time:
0600-1800) in a temperature (22.+-.1.degree. C.)- and
humidity-controlled room. Purina rat chow (Ralston Purina Co., St.
Louis, Mo.) and tap water were freely available. For these studies,
chronic intracerebroventricular (icy) and intracardiac venous
cannulas were implanted under sodium pentobarbital (50 mg/kg, ip)
anesthesia using known techniques. The placement of the icy cannula
was verified by both a positive drinking response to icy carbachol
(100 ng/10 .mu.l) injection on the day after surgery and methylene
blue dye at the time of sacrifice. After surgery, the rats were
placed directly in isolation test chambers with food and water
freely available until body weight returned to preoperative levels
(usually within 5-7 d). During this time, the rats were handled
daily to minimize any stress associated with handling on the day of
the experiment. On the test day, food was removed 1.5 h before the
start of sampling and was returned at the end. Free moving rats
were iv injected with either test sample at various levels (3, 30,
300, 1000 .mu.g/kg) or normal saline at two different time points
during a 6-h sampling period. The times 1100 and 1300 were chosen
because they reflect typical peak and trough periods of GH
secretion, as previously documented. The human ghrelin peptide (5
.mu.g, Phoenix Pharmaceuticals, Inc., Belmont, Calif.) was used as
a positive control in the experiments and was diluted in normal
saline just before use. To assess the central actions of test
compounds on pulsatile GH release, a 10-fold lower dose of the test
sample or normal saline was administered icy at the same time
points, 1100 and 1300. Blood samples (0.35 mL) were withdrawn every
15 min over the 6-h sampling period (time: 1000-1600) from all
animals. To document the rapidity of the GH response to the test
compound, an additional blood sample was obtained 5 min after each
injection. All blood samples were immediately centrifuged, and
plasma was separated and stored at -20.degree. C. for subsequent GH
assay. To avoid hemodynamic disturbance, the red blood cells were
resuspended in normal saline and returned to the animal after
removal of the next blood sample. All animal studies were conducted
under procedures approved by an animal care oversight
committee.
GH Assay Method
[0327] Plasma GH concentrations were measured in duplicate by
double antibody RIA using materials supplied by the NIDDK Hormone
Distribution Program (Bethesda, Md.). The averaged plasma GH values
for 5-6 rats per group are reported in terms of the rat GH
reference preparation. The standard curve was linear within the
range of interest; the least detectable concentration of plasma GH
under the conditions used was approximately 1 ng/mL. All samples
with values above the range of interest were reassayed at dilutions
ranging from 1:2 to 1:10. The intra- and interassay coefficients of
variation were acceptable for duplicate samples of pooled plasma
containing a known GH concentration.
G. Animal Model of Opioid-Induced Bowel Dysfunction
[0328] Opioid analgesics, such as morphine, are well known to delay
gastrointestinal transit, which is a noted side effect for this
class of drugs. (Greenwood-van Meerveld, B.; Gardner, C. J.;
Little, P. J.; Hicks, G. A.; DeHaven-Hudkins, D. L. Preclinical
studies of opioids and opioid antagonists on gastrointestinal
function. Neurogastroenterol. Motil. 2004, 16, 46-53.) The clinical
term for this syndrome is opioid-induced bowel dysfunction (OBD).
The aim of this study was to determine whether test compounds can
effectively reverse morphine-induced delayed gastric emptying and
small intestinal transit in a rat model of opioid-induced bowel
dysfunction.
Experimental Methods
[0329] 1. Rats (male, Sprague-Dawley, 250-300 g, N=6-7/gp) were
implanted with jugular vein catheters to accommodate dosing of test
articles. [0330] 2. Overnight-fasted rats were administered
morphine by sub-cutaneous injection (3 mg/kg). [0331] 3. After 60
minutes, rats were dosed (i.v. bolus) with vehicle, test compound
(0.30, 1.0 mg/kg) or GHRP-6 (0.02 mg/kg) followed by intragastric
gavage of .sup.99mTc methylcellulose (2%) meal. [0332] 4. After 15
minutes, the rats were euthanized and the stomach and consecutive
10 cm segments of the intestine are isolated. Radioactivity
(.sup.99mTc) in each tissue isolate is measured as a means of
measuring gastric emptying and small intestinal transit. [0333] 5.
One-way ANOVA, Dunnet's post-hoc statistical test was applied.
[0334] 6. The experimental design for the study is shown in FIG.
5.
[0335] Results for a representative compound of the invention are
depicted in the graph in FIG. 6.
H. Gastroparesis Animal Model
[0336] High caloric meals are well known to impede gastric
emptying. This observation has recently been exploited by Megens,
A. A.; et al. (unpublished) to develop a rat model for delayed
gastric emptying as experienced in gastroparesis. Such a model can
be employed to demonstrate the utility of the compounds of the
invention for the prevention and/or treatment of gastroparesis.
Materials
[0337] 1. Wistar rats, male, 200-250 g [0338] 2. Chocolate test
meal: 2 mL Clinutren ISO.RTM. (1.0 kcal/mL, Nestle SA, Vevey
Switzerland)
Method
[0339] The test meal was given to the subjects by oral gavage at
time=0. After 60 min, the subjects were sacrificed, the stomachs
excised and the contents weighed. Untreated animals experienced a
significant delay in gastric emptying as denoted by the higher
residual stomach content.
[0340] Test compounds were administered intravenously as aqueous
solutions, or solutions in normal saline, at time=0 at three dose
levels (0.08 mg/kg; 0.30-0.31 mg/kg, 1.25 mg/kg). When necessary,
for example compounds 21, 299 and 415, 10% cyclodextrin (CD) was
added to solubilize the material. Test compounds examined utilizing
subcutaneous injection are administered at time=-30 min. Four to
five (4-5) rats were tested per group, except in the case of the
cyclodextrin control in which ten (10) rats comprised the
group.
[0341] Results were typically reported as percentage relative to
the stomach weight for injection only of solvent as a control and
illustrate the gastric emptying capability of the compounds of the
present invention.
I. Combination Animal Model of Postoperative Ileus and
Opioid-Induced Bowel Dysfunction
[0342] Post-operative ileus patients are typically prescribed
opioid analgesics for the treatment of post-surgical pain.
Unfortunately, a well-known side effect of the opioid analgesics is
to exacerbate the underlying ileus. The aim of this study was to
determine whether a representative compound of the invention is
effective in a POI-rat model concurrently dosed with typical opioid
analgesics such as morphine.
Experimental Methods
[0343] 1. POI model adapted from that of Kalff (Kalff, J. C.;
Schraut, W. H.; Simmons, R. L.; Bauer, A. J. Surgical manipulation
of the gut elicits an intestinal muscularis inflammatory response
resulting in postsurgical ileus. Ann. Surg. 1998, 228, 652-663.) as
described in Example F above. [0344] 2. Rats (male, Sprague-Dawley,
250-300 g, N=6-8/group) were implanted with jugular vein catheters
to accommodate dosing of test articles. [0345] 3. Rats were fasted
overnight, then dosed (s.c.) with morphine (3 mg/kg). [0346] 4.
After 30 minutes, the rats were anesthetized with isoflurane and
subjected to abdominal surgery. [0347] 5. Following an abdominal
incision, the small intestine caecum and large intestine were
eviscerated for a period of 15 minutes and kept moist with saline.
[0348] 6. A "running of the bowel" was performed, a
clinically-relevant manipulation of the intestines characterized by
first pinching the upper small intestine and continuing this
manipulation down through the large intestine. [0349] 7. 30 minutes
after initial anesthesia, the rats are dosed (i.v. bolus) with
vehicle or test compound (0.3, 1, 3 mg/kg) immediately after
intragastric gavage of .sup.99mTc methylcellulose (2%) meal. [0350]
8. 15 minutes after the meal, the rats were euthanized and the
stomach and consecutive 10 cm segments of the intestine were
isolated. Radioactivity (.sup.99mTc) in each tissue isolate was
measured to evaluate gastric emptying and small intestinal transit
as previously described. [0351] 9. The experimental design for this
study is depicted in FIG. 7.
[0352] Results for a representative compound of the invention are
depicted in FIGS. 8 and 9.
4. Pharmaceutical Compositions
[0353] The macrocyclic compounds of the present invention or
pharmacologically acceptable salts thereof according to the
invention may be formulated into pharmaceutical compositions of
various dosage forms. To prepare the pharmaceutical compositions of
the invention, one or more compounds, including optical isomers,
enantiomers, diastereomers, racemates or stereochemical mixtures
thereof, or pharmaceutically acceptable salts thereof as the active
ingredient is intimately mixed with appropriate carriers and
additives according to techniques known to those skilled in the art
of pharmaceutical formulations.
[0354] A pharmaceutically acceptable salt refers to a salt form of
the compounds of the present invention in order to permit their use
or formulation as pharmaceuticals and which retains the biological
effectiveness of the free acids and bases of the specified compound
and that is not biologically or otherwise undesirable. Examples of
such salts are described in Handbook of Pharmaceutical Salts:
Properties, Selection, and Use, Wermuth, C. G. and Stahl, P. H.
(eds.), Wiley-Verlag Helvetica Acta, Zurich, 2002 [ISBN
3-906390-26-8]. Examples of such salts include alkali metal salts
and addition salts of free acids and bases. Examples of
pharmaceutically acceptable salts, without limitation, include
sulfates, pyrosulfates, bisulfates, sulfites, bisulfites,
phosphates, monohydrogenphosphates, dihydrogenphosphates,
metaphosphates, pyrophosphates, chlorides, bromides, iodides,
acetates, propionates, decanoates, caprylates, acrylates, formates,
isobutyrates, caproates, heptanoates, propiolates, oxalates,
malonates, succinates, suberates, sebacates, fumarates, maleates,
butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates,
methylbenzoates, dinitrobenzoates, hydroxybenzoates,
methoxybenzoates, phthalates, xylenesulfonates, phenylacetates,
phenylpropionates, phenylbutyrates, citrates, lactates,
.gamma.-hydroxybutyrates, glycollates, tartrates,
methanesulfonates, ethane sulfonates, propanesulfonates,
toluenesulfonates, naphthalene-1-sulfonates,
naphthalene-2-sulfonates, and mandelates.
[0355] If an inventive compound is a base, a desired salt may be
prepared by any suitable method known to those skilled in the art,
including treatment of the free base with an inorganic acid, such
as, without limitation, hydrochloric acid, hydrobromic acid,
hydroiodic, carbonic acid, sulfuric acid, nitric acid, phosphoric
acid, and the like, or with an organic acid, including, without
limitation, formic acid, acetic acid, propionic acid, maleic acid,
succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic
acid, oxalic acid, stearic acid, ascorbic acid, glycolic acid,
salicylic acid, pyranosidyl acid, such as glucuronic acid or
galacturonic acid, alpha-hydroxy acid, such as citric acid or
tartaric acid, amino acid, such as aspartic acid or glutamic acid,
aromatic acid, such as benzoic acid or cinnamic acid, sulfonic
acid, such as p-toluenesulfonic acid, methanesulfonic acid,
ethanesulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic
acid, cyclohexyl-aminosulfonic acid or the like.
[0356] If an inventive compound is an acid, a desired salt may be
prepared by any suitable method known to the art, including
treatment of the free acid with an inorganic or organic base, such
as an amine (primary, secondary, or tertiary); an alkali metal or
alkaline earth metal hydroxide; or the like. Illustrative examples
of suitable salts include organic salts derived from amino acids
such as glycine, lysine and arginine; ammonia; primary, secondary,
and tertiary amines such as ethylenediamine,
N,N'-dibenzylethylenediamine, diethanolamine, choline, and
procaine, and cyclic amines, such as piperidine, morpholine, and
piperazine; as well as inorganic salts derived from sodium,
calcium, potassium, magnesium, manganese, iron, copper, zinc,
aluminum, and lithium.
[0357] The carriers and additives used for such pharmaceutical
compositions can take a variety of forms depending on the
anticipated mode of administration. Thus, compositions for oral
administration may be, for example, solid preparations such as
tablets, sugar-coated tablets, hard capsules, soft capsules,
granules, powders and the like, with suitable carriers and
additives being starches, sugars, binders, diluents, granulating
agents, lubricants, disintegrating agents and the like. Because of
their ease of use and higher patient compliance, tablets and
capsules represent the most advantageous oral dosage forms for many
medical conditions.
[0358] Similarly, compositions for liquid preparations include
solutions, emulsions, dispersions, suspensions, syrups, elixirs,
and the like with suitable carriers and additives being water,
alcohols, oils, glycols, preservatives, flavoring agents, coloring
agents, suspending agents, and the like. Typical preparations for
parenteral administration comprise the active ingredient with a
carrier such as sterile water or parenterally acceptable oil
including polyethylene glycol, polyvinyl pyrrolidone, lecithin,
arachis oil or sesame oil, with other additives for aiding
solubility or preservation may also be included. In the case of a
solution, it can be lyophilized to a powder and then reconstituted
immediately prior to use. For dispersions and suspensions,
appropriate carriers and additives include aqueous gums,
celluloses, silicates or oils.
[0359] The pharmaceutical compositions according to embodiments of
the present invention include those suitable for oral, rectal,
topical, inhalation (e.g., via an aerosol) buccal (e.g.,
sub-lingual), vaginal, topical (i.e., both skin and mucosal
surfaces, including airway surfaces), transdermal administration
and parenteral (e.g., subcutaneous, intramuscular, intradermal,
intraarticular, intrapleural, intraperitoneal, intrathecal,
intracerebral, intracranially, intraarterial, or intravenous),
although the most suitable route in any given case will depend on
the nature and severity of the condition being treated and on the
nature of the particular active agent which is being used.
[0360] Compositions for injection will include the active
ingredient together with suitable carriers including propylene
glycol-alcohol-water, isotonic water, sterile water for injection
(USP), emulPhor.TM.-alcohol-water, cremophor-EL.TM. or other
suitable carriers known to those skilled in the art. These carriers
may be used alone or in combination with other conventional
solubilizing agents such as ethanol, propylene glycol, or other
agents known to those skilled in the art.
[0361] Where the macrocyclic compounds of the present invention are
to be applied in the form of solutions or injections, the compounds
may be used by dissolving or suspending in any conventional
diluent. The diluents may include, for example, physiological
saline, Ringer's solution, an aqueous glucose solution, an aqueous
dextrose solution, an alcohol, a fatty acid ester, glycerol, a
glycol, an oil derived from plant or animal sources, a paraffin and
the like. These preparations may be prepared according to any
conventional method known to those skilled in the art.
[0362] Compositions for nasal administration may be formulated as
aerosols, drops, powders and gels. Aerosol formulations typically
comprise a solution or fine suspension of the active ingredient in
a physiologically acceptable aqueous or non-aqueous solvent. Such
formulations are typically presented in single or multidose
quantities in a sterile form in a sealed container. The sealed
container can be a cartridge or refill for use with an atomizing
device. Alternatively, the sealed container may be a unitary
dispensing device such as a single use nasal inhaler, pump atomizer
or an aerosol dispenser fitted with a metering valve set to deliver
a therapeutically effective amount, which is intended for disposal
once the contents have been completely used. When the dosage form
comprises an aerosol dispenser, it will contain a propellant such
as a compressed gas, air as an example, or an organic propellant
including a fluorochlorohydrocarbon or fluorohydrocarbon.
[0363] Compositions suitable for buccal or sublingual
administration include tablets, lozenges and pastilles, wherein the
active ingredient is formulated with a carrier such as sugar and
acacia, tragacanth or gelatin and glycerin.
[0364] Compositions for rectal administration include suppositories
containing a conventional suppository base such as cocoa
butter.
[0365] Compositions suitable for transdermal administration include
ointments, gels and patches.
[0366] Other compositions known to those skilled in the art can
also be applied for percutaneous or subcutaneous administration,
such as plasters.
[0367] Further, in preparing such pharmaceutical compositions
comprising the active ingredient or ingredients in admixture with
components necessary for the formulation of the compositions, other
conventional pharmacologically acceptable additives may be
incorporated, for example, excipients, stabilizers, antiseptics,
wetting agents, emulsifying agents, lubricants, sweetening agents,
coloring agents, flavoring agents, isotonicity agents, buffering
agents, antioxidants and the like. As the additives, there may be
mentioned, for example, starch, sucrose, fructose, dextrose,
lactose, glucose, mannitol, sorbitol, precipitated calcium
carbonate, crystalline cellulose, carboxymethylcellulose, dextrin,
gelatin, acacia, EDTA, magnesium stearate, talc,
hydroxypropylmethylcellulose, sodium metabisulfite, and the
like.
[0368] In some embodiments, the composition is provided in a unit
dosage form such as a tablet or capsule.
[0369] In further embodiments, the present invention provides kits
including one or more containers comprising pharmaceutical dosage
units comprising an effective amount of one or more compounds of
the present invention.
[0370] The present invention further provides prodrugs comprising
the compounds described herein. The term "prodrug" is intended to
mean a compound that is converted under physiological conditions or
by solvolysis or metabolically to a specified compound that is
pharmaceutically active. The "prodrug" can be a compound of the
present invention that has been chemically derivatized such that,
(i) it retains some, all or none of the bioactivity of its parent
drug compound, and (ii) it is metabolized in a subject to yield the
parent drug compound. The prodrug of the present invention may also
be a "partial prodrug" in that the compound has been chemically
derivatized such that, (i) it retains some, all or none of the
bioactivity of its parent drug compound, and (ii) it is metabolized
in a subject to yield a biologically active derivative of the
compound. Known techniques for derivatizing compounds to provide
prodrugs can be employed. Such methods may utilize formation of a
hydrolyzable coupling to the compound.
[0371] The present invention further provides that the compounds of
the present invention may be administered in combination with a
therapeutic agent used to prevent and/or treat metabolic and/or
endocrine disorders, gastrointestinal disorders, cardiovascular
disorders, obesity and obesity-associated disorders, central
nervous system disorders, genetic disorders, hyperproliferative
disorders and inflammatory disorders. Exemplary agents include
analgesics (including opioid analgesics), anesthetics, antifungals,
antibiotics, antiinflammatories (including nonsteroidal
anti-inflammatory agents), anthelmintics, antiemetics,
antihistamines, antihypertensives, antipsychotics, antiarthritics,
antitussives, antivirals, cardioactive drugs, cathartics,
chemotherapeutic agents (such as DNA-interactive agents,
antimetabolites, tubulin-interactive agents, hormonal agents, and
agents such as asparaginase or hydroxyurea), corticoids (steroids),
antidepressants, depressants, diuretics, hypnotics, minerals,
nutritional supplements, parasympathomimetics, hormones (such as
corticotrophin releasing hormone, adrenocorticotropin, growth
hormone releasing hormone, growth hormone, thyrptropin-releasing
hormone and thyroid stimulating hormone), sedatives, sulfonamides,
stimulants, sympathomimetics, tranquilizers, vasoconstrictors,
vasodilators, vitamins and xanthine derivatives.
[0372] Subjects suitable to be treated according to the present
invention include, but are not limited to, avian and mammalian
subjects, and are preferably mammalian. Mammals of the present
invention include, but are not limited to, canines, felines,
bovines, caprines, equines, ovines, porcines, rodents (e.g. rats
and mice), lagomorphs, primates, humans, and the like, and mammals
in utero. Any mammalian subject in need of being treated according
to the present invention is suitable. Human subjects are preferred.
Human subjects of both genders and at any stage of development
(i.e., neonate, infant, juvenile, adolescent, adult) can be treated
according to the present invention.
[0373] Illustrative avians according to the present invention
include chickens, ducks, turkeys, geese, quail, pheasant, ratites
(e.g., ostrich) and domesticated birds (e.g., parrots and
canaries), and birds in ovo.
[0374] The present invention is primarily concerned with the
treatment of human subjects, but the invention can also be carried
out on animal subjects, particularly mammalian subjects such as
mice, rats, dogs, cats, livestock and horses for veterinary
purposes, and for drug screening and drug development purposes.
[0375] In therapeutic use for treatment of conditions in mammals
(i.e. humans or animals) for which a modulator, such as an agonist,
of the ghrelin receptor is effective, the compounds of the present
invention or an appropriate pharmaceutical composition thereof may
be administered in an effective amount. Since the activity of the
compounds and the degree of the therapeutic effect vary, the actual
dosage administered will be determined based upon generally
recognized factors such as age, condition of the subject, route of
delivery and body weight of the subject. The dosage can be from
about 0.1 to about 100 mg/kg, administered orally 1-4 times per
day. In addition, compounds can be administered by injection at
approximately 0.01-20 mg/kg per dose, with administration 1-4 times
per day. Treatment could continue for weeks, months or longer.
Determination of optimal dosages for a particular situation is
within the capabilities of those skilled in the art.
5. Methods of Use
[0376] The compounds of formula I, II, III and/or IV of the present
invention can be used for the prevention and treatment of a range
of gastrointestinal disorders including postoperative ileus,
gastroparesis, opioid-induced bowel dysfunction, short bowel
syndrome, chronic intestinal pseudo-obstruction, irritable bowel
syndrome (IBS), non-ulcer dyspepsia, Crohn's disease,
gastroesophogeal reflux disorders, constipation, ulcerative
colitis, pancreatitis, infantile hypertrophic pyloric stenosis,
carcinoid syndrome, malabsorption syndrome, diarrhea, diabetes
including diabetes mellitus (type II diabetes), obesity, atrophic
colitis, gastritis, gastric stasis, gastrointestinal dumping
syndrome, postgastroenterectomy syndrome, celiac disease, an eating
disorder or obesity.
[0377] According to a further aspect of the invention, there is
provided a method for the treatment of multiple gastrointestinal
disorders including post-operative ileus, gastroparesis, such as
that resulting from type I or type II diabetes or surgery,
opioid-induced bowel dysfunction, short bowel syndrome,
gastrointestinal dumping syndrome, postgastroenterectomy syndrome,
celiac disease and other gastrointestinal disorders, which method
comprises administering to said patient an effective amount of at
least one member selected from the compounds disclosed herein
having the ability to modulate the ghrelin receptor.
[0378] In particular embodiments, the macrocyclic compounds of the
present invention can be used to treat post-operative ileus in
combination with opioid-induced bowel dysfunction. In other
embodiments, the compounds of the present invention can be used to
treat gastroparesis in combination with opioid-induced bowel
dysfunction. In still other embodiments, the compounds of the
present invention can be used to treat post-surgical gastroparesis
in combination with opioid-induced bowel dysfunction.
[0379] In another embodiment, the compounds of the present
invention can be used to treat post-surgical gastroparesis.
[0380] As used herein, "treatment" is not necessarily meant to
imply cure or complete abolition of the disorder or symptoms
associated therewith.
[0381] The compounds of the present invention can further be
utilized for the preparation of a medicament for the treatment of a
range of medical conditions involving gastrointestinal motility
disorders.
[0382] Further embodiments of the present invention will now be
described with reference to the following examples. It should be
appreciated that these examples are for the purposes of
illustrating embodiments of the present invention, and do not limit
the scope of the invention.
A. Biological Results
[0383] 1. Effect of Compounds 25 and 298 on Gastric Emptying of a
Solid Meal in Na ve Rat
Objectives
[0384] 1. To ascertain data for representative compounds 25 and 298
as prokinetic agents with potent effects on gastric emptying, a
model for gastroparesis.
Methods
[0384] [0385] 1. Overnight-fasted rats (male, Wistar, .about.200 g,
N=5/group) were given a meal of methylcellulose (2%) by
intragastric gavage. The meal was labeled with phenol red (0.05%).
[0386] 2. Test articles (i.e. vehicle, compound 25, compound 298,
metoclopramide, GHRP-6, etc.) were administered by intravenous
injection immediately after meal. [0387] 3. Animals were sacrificed
15 minutes later; the stomach was immediately removed and
homogenized in 0.1 N NaOH and centrifuged. [0388] 4. Total phenol
red remaining in the stomach was quantified by a colorimetric
method at 560 nm. [0389] 5. A >30% increase in gastric emptying,
detected based on the phenol red concentration in comparison to the
control group, is considered significant.
Results
[0390] Metoclopramide (marketed gastroparesis product) and GHRP-6
(reference peptide agonists at hGHS-R1a) all demonstrated
significant gastric emptying in the assay. Compounds 25 and 298 at
100 .mu.g/kg caused a significant increase (.gtoreq.30%) in gastric
emptying relative to the vehicle control group. The relative
efficacy (39% increase) of compounds 25 and 298 at 100 .mu.g/kg
i.v. was similar to concurrently run positive reference agents
GHRP-6 at 20 .mu.g/kg i.v. (40% increase) and metoclopramide at 10
mg/kg i.v. (41% increase). Accordingly, compounds 25 and 298 at a
dose of 100 .mu.g/kg demonstrated gastrokinetic activity in rats,
with efficiency similar to GHRP-6 at 20 .mu.g/kg and metoclopramide
at 10 mg/kg. Compound 25 also demonstrated significant gastric
emptying at 30 .mu.g/kg. Further, compounds 25 (FIG. 2A) and 298
(FIG. 2B) resulted in gastric emptying in a dose-dependent manner
with .about.100-fold greater potency compared to metoclopramide, a
currently used drug with prokinetic activity, based on the
different dose levels. This result show that these compounds are
more potent than other compounds interacting at this receptor
previously found to enhance GI motility, which were unable to
promote gastric emptying at 100 .mu.g/kg (U.S. Pat. No.
6,548,501).
2. Effect of Compound 298 in the Treatment of Post-operative Ileus
in Rat Objective
[0391] To measure the therapeutic utility of compound 298 in a rat
model of post-operative ileus (POI).
Methods
[0391] [0392] 1. Model adapted from Kalff. (Kalff, J. C.; Schraut,
W. H.; Simmons, R. L.; Bauer, A. J. Surgical manipulation of the
gut elicits an intestinal muscularis inflammatory response
resulting in postsurgical ileus. Ann. Surg. 1998, 228, 652-663.)
[0393] 2. Rats (male, Sprague-Dawley, 250-300 g) were implanted
with jugular vein catheters to accommodate dosing of test articles.
[0394] 3. Rats were fasted O/N, anesthetized with isofluorane and
subjected to abdominal surgery. [0395] 4. Following an abdominal
incision, the small intestine caecum and large intestine were
eviscerated for a period of 15 min and kept moist with saline.
[0396] 5. A "running of the bowel" was performed, a
clinically-relevant manipulation of the intestines characterized by
first pinching the upper small intestine and continuing this
manipulation down through the large intestine. [0397] 6. Rats were
allowed a 15 min recovery beginning after the disappearance of any
effects of the isofluorane anesthesia. [0398] 7. Rats were dosed
with vehicle or compound 298 (30, 100, or 300 .mu.g/kg, i.v.,
N=6/gp) followed by intragastric gavage of .sup.99mTc
methylcellulose (2%) meal. [0399] 8. After 15 min, the rats were
euthanized and the stomach and consecutive 10 cm segments of the
intestine were isolated. Radioactivity (.sup.99mTc) in each tissue
isolate was measured as a means of measuring the transit of the
meal.
Results
[0400] In FIG. 3, the distribution of the bars indicates the
distribution of the meal in the stomach (`ST`) and consecutive 10
cm segments of the small intestine at 15 min post-oral gavage.
Abdominal surgery coupled with a running of the bowel caused a
significant ileus in rats as determined by comparison of the na ve
(i.e. unoperated) and POI treatment groups. Compound 298
significantly increased gastric emptying and intestinal transit at
test concentrations of 100 and 300 .mu.g/kg (i.v.). The data
corresponding to the 100 .mu.g/kg dose is presented in FIG. 3. At
100 .mu.g/kg (i.v.), compound 298 significantly promoted GI transit
by 2.7.times. as measured by the geometric center of the meal in
comparison to the POI+vehicle treatment group. FIG. 4 shows that
even at doses as low as 30 .mu.g/kg, compound 298 has an effect at
improving gastric emptying in this model. Compound 298 improved
gastric emptying and intestinal transit in rats with post-operative
ileus. Compound 298 can treat an existing, post-surgical ileus;
thus, prophylactic, use prior to surgery can be employed, but is
not required, as is the case for some, if not all, opioid
antagonists currently in clinical development. (Greenwood-van
Meerveld, B.; Gardner, C. J.; Little, P. J.; Hicks, G. A.;
DeHaven-Hudkins, D. L. Preclinical studies of opioids and opioid
antagonists on gastrointestinal function. Neurogastroenterol.
Motil. 2004, 16, 46-53; Leslie, J. B. Alvimopan for the management
of postoperative ileus. Ann. Pharmacother. 2005, 39, 1502-1510;
Yuan, C.-S.; Israel, R. J. Methylnaltrexone, a novel peripheral
opioid antagonist for the treatment of opioid side effects. Exp.
Opin. Invest. Drugs 2006, 15, 541-552.)
3. Effect of Compound 298 on Gastric Emptying and Gastrointestinal
Transit in a Model of Opioid-Delayed Gastric Emptying
[0401] Opioid analgesics, such as morphine, are well known to delay
gastrointestinal transit which is an important side-effect for this
class of drugs. The clinical term for this syndrome is opioid bowel
dysfunction (OBD). Importantly, patients recovering from abdominal
surgery experience post-operative ileus that is further exacerbated
by concomitant opioid therapy for post-surgical pain.
Objective
[0402] 1. To determine whether compounds of the invention as
represented by compound 298, may have therapeutic utility in the
treatment of OBD.
Methods
[0402] [0403] 1. Rats (male, Sprague-Dawley, 250-300 g) were
implanted with jugular vein catheters to accommodate dosing of test
articles. [0404] 2. Overnight-fasted rats were administered
morphine (3 mg/kg s.c.). [0405] 3. After 60 min, rats were to be
dosed with vehicle or compound 298 (300 or 1000 .mu.g/kg, i.v.,
n=4-to-6/) followed by intragastric gavage of .sup.99mTc
methylcellulose (2%) meal. [0406] 4. After 15 min, the rats were
euthanized and the stomach and consecutive 10 cm segments of the
intestine are isolated. Radioactivity (.sup.99mTc) in each tissue
isolate was measured as a means of measuring the transit of the
meal. [0407] 5. The experimental design is shown in FIG. 5.
Results
[0408] A preliminary study demonstrated that morphine (3 mg/kg,
s.c.) significantly delayed gastric emptying and small intestinal
transit in rats. Compound 298 significantly accelerated
opioid-delayed gastric emptying and opioid-delayed small intestinal
gastrointestinal transit in a dose-dependent manner (Table 1, data
presented as mean.+-.sem).
TABLE-US-00001 TABLE 1 Effect of compound 298 on opioid-delayed
gastrointestinal transit Treatment Intragastric Residue (%)
Geometric Center Naive 0.35 .+-. 0.05 4.55 .+-. 0.90 Vehicle 0.67
.+-. 0.04 1.79 .+-. 0.22 TZP-101 0.45 .+-. 0.09 3.23 .+-. 0.82
(0.30 mg/kg) TZP-101 0.30 .+-. 0.06 3.73 .+-. 0.61 (1.0 mg/kg)
GHRP-6 0.48 .+-. 0.10 3.38 .+-. 0.76
[0409] Compound 298 decreased intragastric residue and increased
geometric center relative to the difference between the vehicle and
blank controls at both 0.30 mg/kg and 1.0 mg/kg dose levels (FIG.
6).
4. Effect of Compound 298 in an Animal Model of Postoperative Ileus
and Opioid-Induced Bowel Dysfunction
[0410] Post-operative ileus patients are typically prescribed
opioid analgesics for the treatment of post-surgical pain. A side
effect of the opioid analgesics is to exacerbate the underlying
ileus. The aim of this study was to demonstrate whether
representative compound 298 is effective in a POI rat model
concurrently dosed with a representative opioid analgesic,
morphine.
Experimental Method
[0411] 1. POI model was adapted from that of Kalff (Kalff, J. C.;
Schraut, W. H.; Simmons, R. L.; Bauer, A. J. Surgical manipulation
of the gut elicits an intestinal muscularis inflammatory response
resulting in postsurgical ileus. Ann Surg. 1998, 228, 652-663.) as
described in Example F above. [0412] 2. Rats (male, Sprague-Dawley,
250-300 g, N=6-8/group) were implanted with jugular vein catheters
to accommodate dosing of test articles. [0413] 3. Rats were fasted
overnight and dosed (s.c.) with morphine (3 mg/kg) [0414] 4. After
30 minutes, the rats were anesthetized with isoflurane and
subjected to abdominal surgery. [0415] 5. Following an abdominal
incision, the small intestine caecum and large intestine are
eviscerated for a period of 15 minutes and kept moist with saline.
[0416] 6. A "running of the bowel" was performed, a
clinically-relevant manipulation of the intestines characterized by
first pinching the upper small intestine and continuing this
manipulation down through the large intestine. [0417] 7. 30 minutes
after initial anesthesia, rats were dosed (i.v. bolus) with vehicle
or compound 298 (0.03, 0.1, 0.3, 1, 3 mg/kg) immediately after
intragastric gavage of .sup.99mTc methylcellulose (2%) meal [0418]
8. 15 minutes after the meal, the rats were euthanized and the
stomach and consecutive 10 cm segments of the intestine are
isolated. Radioactivity (.sup.99mTc) in each tissue isolate is
measured to evaluate gastric emptying and small intestinal transit
as previously described. [0419] 9. The experimental design for this
study is depicted in FIG. 7.
Results and Discussion
[0420] The combination of morphine pre-treatment and abdominal
surgery causes a significant delay in gastric emptying and small
intestinal transit as determined by comparison of the naive
(historic) and vehicle groups. The results indicate that compound
298 (0.1, 0.3, 1, 3 mg/kg) significantly accelerates gastric
emptying (FIG. 8) and small intestinal transit (FIG. 9) in this
combination disease model of POI and opioid-induced bowel
dysfunction. Compound 298 is effective when administered after
induction of ileus and concurrent exposure to morphine indicating
that compound 298 is not restricted to prophylactic use in this
disease model as are alternative treatments such as selective
peripheral opioid antagonists.
[0421] Compound 298 is effective at restoring GI motility at dose
levels as low as 100 .mu.g/kg. This level is consistent with the
dose level required to induce GI motility in either POI (100
.mu.g/kg) or OBD (300 .mu.g/kg) alone.
[0422] The foregoing is illustrative of the present invention, and
is not to be construed as limiting thereof. The invention is
defined by the following claims, with equivalents of the claims to
be included therein.
* * * * *