U.S. patent application number 12/467758 was filed with the patent office on 2009-11-19 for amino acid derived prodrugs of propofol, compositions and uses thereof.
This patent application is currently assigned to XenoPort, Inc.. Invention is credited to Mark A. Gallop, Vivek Sasikumar, Feng Xu.
Application Number | 20090286763 12/467758 |
Document ID | / |
Family ID | 35311506 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090286763 |
Kind Code |
A1 |
Xu; Feng ; et al. |
November 19, 2009 |
AMINO ACID DERIVED PRODRUGS OF PROPOFOL, COMPOSITIONS AND USES
THEREOF
Abstract
The present invention provides propofol prodrugs, methods of
making propofol prodrugs, pharmaceutical compositions of propofol
prodrugs and methods of using propofol prodrugs and pharmaceutical
compositions thereof to treat or prevent diseases or disorders such
as migraine headache pain and post-chemotherapy or post-operative
surgery nausea and vomiting.
Inventors: |
Xu; Feng; (Palo Alto,
CA) ; Gallop; Mark A.; (Santa Clara, CA) ;
Sasikumar; Vivek; (Indianapolis, IN) |
Correspondence
Address: |
DORSEY & WHITNEY, LLP;INTELLECTUAL PROPERTY DEPARTMENT
370 SEVENTEENTH STREET, SUITE 4700
DENVER
CO
80202-5647
US
|
Assignee: |
XenoPort, Inc.
Santa Clara
CA
|
Family ID: |
35311506 |
Appl. No.: |
12/467758 |
Filed: |
May 18, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11180064 |
Jul 12, 2005 |
7550506 |
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12467758 |
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60587611 |
Jul 12, 2004 |
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Current U.S.
Class: |
514/171 ;
514/512; 558/273 |
Current CPC
Class: |
A61K 38/00 20130101;
C07K 5/0606 20130101; C07C 237/12 20130101; C07C 323/60 20130101;
C07C 229/22 20130101; A61P 25/08 20180101; C07K 5/06095 20130101;
A61P 1/08 20180101; C07C 237/20 20130101; C07K 5/06165 20130101;
A61P 25/06 20180101; C07D 233/64 20130101; C07K 5/06086 20130101;
A61P 21/02 20180101; A61P 25/00 20180101; C07K 5/06147 20130101;
A61P 21/04 20180101; A61P 25/22 20180101; A61P 25/28 20180101; A61P
25/14 20180101; C07K 5/06113 20130101; A61P 25/16 20180101; C07K
5/06043 20130101; C07K 5/06069 20130101; C07K 5/06026 20130101;
C07K 5/06052 20130101 |
Class at
Publication: |
514/171 ;
514/512; 558/273 |
International
Class: |
A61K 31/56 20060101
A61K031/56; A61K 31/265 20060101 A61K031/265; C07C 69/96 20060101
C07C069/96 |
Claims
1-12. (canceled)
13. A compound of Formula (I) is provided: ##STR00009## or a
pharmaceutically acceptable salt, hydrate, solvate or N-oxide
thereof, wherein: R.sup.1 is selected from the group consisting of
hydrogen, (R.sup.5NH(CHR.sup.4).sub.pC(O))--, R.sup.6--,
R.sup.6C(O)--, and R.sup.6OC(O)--; R.sup.2 is --OR.sup.7; p is 1 or
2; each R.sup.4 is independently selected from the group consisting
of hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy,
acyl, substituted acyl, alkoxycarbonyl, substituted alkoxycarbonyl,
aryl, substituted aryl, arylalkyl, substituted arylalkyl,
carbamoyl, substituted carbamoyl, cycloalkyl, substituted
cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl,
heteroalkyl, substituted heteroalkyl, heteroaryl, substituted
heteroaryl, heteroarylalkyl, and substituted heteroarylalkyl; or
when R.sup.4 and R.sup.5 are attached to adjacent atoms then
R.sup.4 and R.sup.5 together with the atoms to which they are
bonded form a cycloheteroalkyl or substituted cycloheteroalkyl
ring; R.sup.5 is selected from the group consisting of hydrogen,
R.sup.6--, R.sup.6C(O)--, and R.sup.6OC(O)--; R.sup.6 is selected
from the group consisting of alkyl, substituted alkyl, aryl,
substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl,
substituted cycloalkyl, cycloheteroalkyl, heteroaryl, substituted
heteroaryl, and heteroarylalkyl; and R.sup.7 is selected from the
group consisting of hydrogen, alkyl, substituted alkyl, aryl,
substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl,
substituted cycloalkyl, cycloheteroalkyl, heteroaryl, substituted
heteroaryl, and heteroarylalkyl.
14. The compound of claim 13, wherein: R.sup.1 is
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--; p is 1; R.sup.5 is hydrogen;
and R.sup.4 is selected from the group consisting of hydrogen,
alkanyl, substituted alkanyl, aryl, substituted aryl, arylalkanyl,
substituted arylalkanyl, cycloalkanyl, heteroarylalkanyl, and
substituted heteroarylalkanyl.
15. The compound of claim 13, wherein: R.sup.1 is
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--; p is 1; R.sup.5 is hydrogen;
and R.sup.4 is selected from the group consisting of hydrogen,
methyl, isopropyl, isobutyl, sec-butyl, t-butyl, cyclopentyl,
cyclohexyl, --CH.sub.2OH, --CH(OH)CH.sub.3, --CH.sub.2CO.sub.2H,
--CH.sub.2CH.sub.2CO.sub.2H, --CH.sub.2CONH.sub.2,
--CH.sub.2CH.sub.2CONH.sub.2, --CH.sub.2CH.sub.2SCH.sub.3,
--CH.sub.2SH, --CH.sub.2(CH.sub.2).sub.3NH.sub.2,
--CH.sub.2CH.sub.2CH.sub.2NHC(NH)NH.sub.2, phenyl, benzyl,
4-hydroxybenzyl, 4-imidazolylmethyl, and 3-indolylmethyl.
16. The compound of claim 13, wherein R.sup.7 is selected from the
group consisting of hydrogen, C.sub.1-4 alkyl, phenyl, substituted
phenyl, benzyl, and substituted benzyl.
17. The compound of claim 15, wherein R.sup.7 is selected from the
group consisting of hydrogen, C.sub.1-4 alkyl, phenyl, substituted
phenyl, benzyl, and substituted benzyl.
18. The compound of claim 15, wherein the .alpha.-carbon of the
N-terminal amino acid residue is of the L-configuration.
19. The compound of claim 15, wherein the .alpha.-carbon of the
N-terminal amino acid residue is of the D-configuration.
20. The compound of claim 15, wherein the .alpha.-carbon of the
C-terminal amino acid residue is of the L-configuration.
21. The compound of claim 15, wherein the .alpha.-carbon of the
C-terminal amino acid residue is of the D-configuration.
22. A pharmaceutical composition comprising a therapeutically
effective amount of a compound according to claim 13 and a
pharmaceutically acceptable vehicle.
23. The composition of claim 22, for treatment of nausea and
vomiting comprising a 5-HT.sub.3 antagonist, a corticosteroid, or a
combination thereof.
24. The composition of claim 23, wherein the 5-HT.sub.3 antagonist
is selected from the group consisting of ondansetron, granisetron,
dolasetron, and palonosetron; and the corticosteroid is
dexamethasone.
25. A pharmaceutical composition comprising a therapeutically
effective amount of a compound according to claim 17 and a
pharmaceutically acceptable vehicle.
26. The composition of claim 25, for treatment of nausea and
vomiting comprising a 5-HT.sub.3 antagonist, a corticosteroid, or a
combination thereof.
27. The composition of claim 26, wherein the 5-HT.sub.3 antagonist
is selected from the group consisting of ondansetron, granisetron,
dolasetron, and palonosetron; and the corticosteroid is
dexamethasone.
28. A method for treating migraine, nausea, vomiting, anxiety,
seizures, convulsions, trauma of the central nervous system, and
neurodegenerative conditions selected from the group consisting of
Friedrich's disease, Parkinson's disease, Alzheimer's disease,
Huntington's disease, amyotrophic lateral sclerosis, multiple
sclerosis, and Pick disease in a patient, comprising administering
to a patient in need of such treatment a therapeutically effective
amount of a pharmaceutical composition according to claim 22.
29. A method for treating migraine, nausea, vomiting, anxiety,
seizures, convulsions, trauma of the central nervous system, and
neurodegenerative conditions g selected from the group consisting
of Friedrich's disease, Parkinson's disease, Alzheimer's disease,
Huntington's disease, amyotrophic lateral sclerosis, multiple
sclerosis, and Pick disease in a patient, comprising administering
to a patient in need of such treatment a therapeutically effective
amount of a pharmaceutical composition according to claim 25.
30. A method for treating migraine in a patient comprising
administering to a patient in need of such treatment a
therapeutically effective amount of a pharmaceutical composition
according to claim 22.
31. A method for treating migraine in a patient comprising
administering to a patient in need of such treatment a
therapeutically effective amount of a pharmaceutical composition
according to claim 25.
32. A method for treating nausea and vomiting in a patient
comprising administering to a patient in need of such treatment a
therapeutically effective amount of a pharmaceutical composition
according to claim 22.
33. The composition of claim 32, comprising a 5-HT.sub.3
antagonist, a corticosteroid, or a combination thereof.
34. The composition of claim 33, wherein the 5-HT.sub.3 antagonist
is selected from the group consisting of ondansetron, granisetron,
dolasetron, and palonosetron; and the corticosteroid is
dexamethasone.
35. A method for treating nausea and vomiting in a patient
comprising administering to a patient in need of such treatment a
therapeutically effective amount of a pharmaceutical composition
according to claim 25.
36. The composition of claim 35, comprising a 5-HT.sub.3
antagonist, a corticosteroid, or a combination thereof.
37. The composition of claim 36, wherein the 5-HT.sub.3 antagonist
is selected from the group consisting of ondansetron, granisetron,
dolasetron, and palonosetron; and the corticosteroid is
dexamethasone.
Description
[0001] This application is a continuation application of U.S.
patent application Ser. No. 11/180,064, now allowed, which claims
the benefit under 35 U.S.C. .sctn. 119(e) from U.S. Provisional
Application Ser. No. 60/587,611, filed Jul. 12, 2004, each of which
is herein incorporated by reference in its entirety.
1. TECHNICAL FIELD
[0002] The present invention provides propofol prodrugs, methods of
making propofol prodrugs, pharmaceutical compositions of propofol
prodrugs and methods of using propofol prodrugs and pharmaceutical
compositions thereof to treat or prevent diseases or disorders such
as migraine headache pain and post-chemotherapy or post-operative
surgery nausea and vomiting.
2. BACKGROUND ART
[0003] Propofol (2,6-diisopropylphenol), (1), is a low molecular
weight phenol that is widely used as an intravenous
sedative-hypnotic agent in the induction and maintenance of
anesthesia and/or sedation in mammals. The advantages of propofol
as an anesthetic include rapid onset of anesthesia, rapid
clearance, and minimal side effects (Langley et al., Drugs 1988,
35, 334-372). Propofol may mediate hypnotic effects through
interaction with the GABA.sub.A receptor complex, a
hetero-oligomeric ligand-gated chloride ion channel (Peduto et al.,
Anesthesiology 1991, 75, 1000-1009.).
##STR00001##
[0004] Propofol is rapidly metabolized in mammals with the drug
being eliminated predominantly as glucuronidated and sulfated
conjugates of propofol and 4-hydroxypropofol (Langley et al., Drugs
1988, 35, 334-372). Propofol clearance exceeds liver blood flow,
which indicates that extrahepatic tissues contribute to the overall
metabolism of the drug. Human intestinal mucosa glucuronidates
propofol in vitro and oral dosing studies in rats indicate that
approximately 90% of the administered drug undergoes first pass
metabolism, with extraction by the intestinal mucosa accounting for
the bulk of this presystemic elimination (Raoof et al., Pharm. Res.
1996, 13, 891-895). Because of its extensive first-pass metabolism,
propofol is administered by injection or intravenous infusion and
oral administration has not been considered therapeutically
effective.
[0005] Propofol has a broad range of biological and medical
applications, which are evident at sub-anesthetic doses and include
treatment and/or prevention of intractable migraine headache pain
(Krusz et al., Headache 2000, 40, 224-230; Krusz, International
Publication No. WO 00/54588). Propofol, when used to maintain
anesthesia, causes a lower incidence of post-operative nausea and
vomiting ("PONV") when compared to common inhalation anesthetic
agents and numerous controlled clinical studies support the
anti-emetic activity of propofol (Tramer et al., Br. J. Anaesth.
1997, 78, 247-255; Brooker et al., Anaesth. Intensive Care 1998,
26, 625-629; Gan et al., Anesthesiology 1997, 87, 779-784).
Propofol has also been shown to have anti-emetic activity when used
in conjunction with chemotherapeutic compounds (Phelps et al., Ann.
Pharmacother. 1996, 30, 290-292; Borgeat et al., Oncology 1993, 50,
456-459; Borgeat et al., Can. J Anaesth. 1994, 41, 1117-1119;
Tomioka et al., Anesth. Analg. 1999, 89, 798-799). Nausea, retching
and/or vomiting induced by a variety of chemotherapeutic agents
(e.g., cisplatin, cyclophosphamide, 5-fluorouracil, methotrexate,
anthracycline drugs, etc.) has been controlled by low-dose propofol
infusion in patients refractory to prophylaxis with conventional
anti-emetic drugs (e.g., serotonin antagonists and
corticosteroids).
[0006] Propofol has also been used to treat patients with
refractory status epilepticus (Brown et al., Pharmacother. 1998,
32, 1053-1059; Kuisma et al., Epilepsia 1995, 36, 1241-1243; Walder
et al., Neurology 2002, 58, 1327-1332; Sutherland et al., Anaesth.
Intensive Care 1994, 22, 733-737). Further, the anticonvulsant
effects of propofol have also been demonstrated in rat efficacy
models at sub-anesthetic doses (Holtkamp et al., Ann. Neurol. 2001,
49, 260-263; Hasan et al., Pharmacol. Toxicol. 1994, 74,
50-53).
[0007] Propofol has also been used as an antioxidant (Murphy et
al., Br. J. Anaesth. 1992, 68, 613-618; Sagara et al., J.
Neurochem. 1999, 73, 2524-2530; Young et al., Eur. J. Anaesthesiol.
1997, 14, 320-326; Wang et al. Eur. J. Pharmacol. 2002, 452,
303-308). Propofol, at doses typically used for surgical
anesthesia, has observable antioxidant effects in humans (De la
Cruz et al., Anesth. Analg. 1999, 89, 1050-1055). Pathogenesis or
subsequent damage pathways in various neurodegenerative diseases
involve reactive oxygen species and accordingly may be treated or
prevented with antioxidants (Simonian et al., Pharmacol. Toxicol.
1996, 36, 83-106). Examples of specific neurodegenerative diseases
which may be treated or prevented with anti-oxidants include, but
are not limited to, Friedrich's disease, Parkinson's disease,
Alzheimer's disease, Huntington's disease, amyotrophic lateral
sclerosis ("ALS"), multiple sclerosis ("MS"), Pick disease,
inflammatory diseases and diseases caused by inflammatory mediators
such as tumor necrosis factor (TNF) and IL-1.
[0008] A significant problem with the formulation and use of
propofol is poor water solubility. Accordingly, propofol must be
specially formulated in aqueous media using solubilizers or
emulsifiers (Briggs et al., Anaesthesia 1982, 37, 1099-1101). For
example, in a current commercial product (Diprivan.RTM.,
Astra-Zeneca) an oil-in-water emulsion (the emulsifier is the
lecithin mixture Intralipid.RTM.), is used to formulate propofol
(Picard et al., Anesth. Analg. 2000, 90, 963-969). Unfortunately,
the oil-in-water emulsion formulation causes discomfort and pain at
the site of injection.
[0009] One potential solution to the poor water solubility of
propofol which avoids the use of additives, solubilizers or
emulsifiers and the attendant injection site pain, is a
water-soluble, stable propofol prodrug that is converted to
propofol in vivo. (Hendler et al., International Publication No. WO
99/58555; Morimoto et al., International Publication No. WO
00/48572; Hendler et al., U.S. Pat. No. 6,254,853; Stella et al.,
United States Patent Application No. US2001/0025035; Hendler, U.S.
Pat. No. 6,362,234; Hendler, International Publication No. WO
02/13810; Sagara et al., J. Neurochem. 1999, 73, 2524-2530;
Banaszczyk et al., Anesth. Analg. 2002, 95, 1285-1292; Trapani et
al., Int. J. Pharm. 1998, 175, 195-204; Trapani et al., J. Med.
Chem. 1998, 41, 1846-1854; Anderson et al., J. Med. Chem. 2001, 44,
3582-3591; Pop et al., Med. Chem. Res. 1992, 2, 16-21). A
significant problem with these existing propofol prodrugs is their
high stability in vivo. This stability prevents release of
therapeutically significant concentrations of propofol,
particularly when the prodrug is orally administered.
[0010] Accordingly, there is a need for propofol prodrugs, which
are sufficiently labile under physiological conditions to provide
therapeutically effective concentrations of propofol, particularly,
when the prodrug is orally administered.
3. SUMMARY
[0011] Disclosed herein are propofol prodrugs, methods of making
propofol prodrugs, pharmaceutical compositions of propofol prodrugs
and methods of using propofol prodrugs to treat or prevent diseases
or disorders such as migraine headache pain, neurodegenerative
disorders and post-chemotherapy or post-operative surgery nausea
and vomiting which satisfies the above need. In one embodiment,
prodrugs of propofol and pharmaceutical compositions thereof are
orally administered. In another embodiment, prodrugs of propofol
are translocated across the gastrointestinal mucosa via interaction
with transporter proteins expressed within enterocytes lining the
gastrointestinal tract.
[0012] In a first aspect, a compound of structural Formula (I) is
provided:
##STR00002##
[0013] or a pharmaceutically acceptable salt, hydrate, solvate or
N-oxide thereof, wherein:
[0014] R.sup.1 is selected from the group consisting of hydrogen,
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--, R.sup.6--, R.sup.6C(O)-- and
R.sup.6OC(O)--;
[0015] R.sup.2 is --OR.sup.7 or
--[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7];
[0016] p and q are independently 1 or 2;
[0017] each R.sup.4 is independently selected from the group
consisting of hydrogen, alkyl, substituted alkyl, alkoxy,
substituted alkoxy, acyl, substituted acyl, alkoxycarbonyl,
substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, carbamoyl, substituted carbamoyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl,
substituted heteroaryl, heteroarylalkyl and substituted
heteroarylalkyl, or optionally, when R.sup.4 and R.sup.5 are
attached to adjacent atoms then R.sup.4 and R.sup.5 together with
the atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring;
[0018] R.sup.5 is selected from the group consisting of hydrogen,
R.sup.6--, R.sup.6C(O)-- and R.sup.6OC(O)--;
[0019] R.sup.6 is selected from the group consisting of alkyl,
substituted alkyl, aryl, substituted aryl, arylalkyl, substituted
arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,
heteroaryl, substituted heteroaryl and heteroarylalkyl;
[0020] R.sup.7 is selected from the group consisting of hydrogen,
alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, cycloalkyl, substituted cycloalkyl,
cycloheteroalkyl, heteroaryl, substituted heteroaryl and
heteroarylalkyl;
[0021] R.sup.8 is selected from the group consisting of hydrogen,
alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, heteroaryl,
substituted heteroaryl and heteroarylalkyl;
[0022] each R.sup.9 is independently selected from the group
consisting of hydrogen, alkyl, substituted alkyl, alkoxy,
substituted alkoxy, acyl, substituted acyl, alkoxycarbonyl,
substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, carbamoyl, substituted carbamoyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl,
substituted heteroaryl, heteroarylalkyl and substituted
heteroarylalkyl, or optionally, when R.sup.8 and R.sup.9 are
attached to adjacent atoms then R.sup.8 and R.sup.9 together with
the atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring;
[0023] with the proviso that when R.sup.2 is
--[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7] then R.sup.1 is not
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--.
[0024] In still another aspect, pharmaceutical compositions are
provided. The pharmaceutical compositions disclosed herein
generally comprise one or more compounds of Formulae (I)-(III) and
a pharmaceutically acceptable vehicle such as a diluent, carrier,
excipient or adjuvant. The choice of diluent, carrier, excipient
and adjuvant will depend upon, among other factors, the desired
mode of administration. In one embodiment, the mode of
administration is oral.
[0025] In still another aspect, methods for treating various
diseases or disorders are provided. The methods disclosed herein
generally comprise administering one or more compounds of Formulae
(I)-(III) in order to achieve a therapeutically effective
concentration of propofol in the blood and/or tissue of a patient.
The methods are useful for treating or preventing diseases or
disorders including, but not limited to, migraine headache pain,
post-chemotherapy or post-operative surgery nausea and vomiting and
neurodegenerative disorders (e.g., epilepsy, Friedrich's disease,
Parkinson's disease, Alzheimer's disease, Huntington's disease,
amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Pick
disease, etc.). The methods generally involve administering to a
patient in need of such treatment or prevention a therapeutically
effective amount of one or more compounds of Formulae (I)-(III), or
pharmaceutical composition containing one or more compounds of
Formulae (I)-(III).
[0026] In still another aspect, methods for inducing and/or
maintaining anesthesia or sedation in a mammal are provided. The
methods generally involve administering to a patient in need of
such anesthesia or sedation induction and/or maintenance a
therapeutically effective amount of one or more compounds of
Formulae (I)-(III), or pharmaceutical composition containing one or
more compounds of Formulae (I)-(III).
4. DETAILED DESCRIPTION
4.1 Definitions
[0027] "Alkyl" by itself or as part of another substituent refers
to a saturated or unsaturated, branched, straight-chain or cyclic
monovalent hydrocarbon radical derived by the removal of one
hydrogen atom from a single carbon atom of a parent alkane, alkene
or alkyne. Typical alkyl groups include, but are not limited to,
methyl; ethyls such as ethanyl, ethenyl, ethynyl; propyls such as
propan-1-yl, propan-2-yl, cyclopropan-1-yl, prop-1-en-1-yl,
prop-1-en-2-yl, prop-2-en-1-yl (allyl), cycloprop-1-en-1-yl;
cycloprop-2-en-1-yl, prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butyls
such as butan-1-yl, butan-2-yl, 2-methyl-propan-1-yl,
2-methyl-propan-2-yl, cyclobutan-1-yl, but-1-en-1-yl,
but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl,
but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,
cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl,
but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the
like.
[0028] The term "alkyl" is specifically intended to include groups
having any degree or level of saturation, i.e., groups having
exclusively single carbon-carbon bonds, groups having one or more
double carbon-carbon bonds, groups having one or more triple
carbon-carbon bonds and groups having mixtures of single, double
and triple carbon-carbon bonds. Where a specific level of
saturation is intended, the expressions "alkanyl," "alkenyl," and
"alkynyl" are used. Preferably, an alkyl group comprises from 1 to
20 carbon atoms, more preferably, from 1 to 10 carbon atoms, even
more preferably, 1 to 6 carbon atoms. "C.sub.1-6 alkyl" refers to
an alkyl group containing from 1 to 6 carbon atoms.
[0029] "Alkanyl" by itself or as part of another substituent refers
to a saturated branched, straight-chain or cyclic alkyl radical
derived by the removal of one hydrogen atom from a single carbon
atom of a parent alkane. Typical alkanyl groups include, but are
not limited to, methanyl; ethanyl; propanyls such as propan-1-yl,
propan-2-yl (isopropyl), cyclopropan-1-yl, etc.; butanyls such as
butan-1-yl, butan-2-yl (sec-butyl), 2-methyl-propan-1-yl
(isobutyl), 2-methyl-propan-2-yl (t-butyl), cyclobutan-1-yl, etc.;
and the like.
[0030] "Alkenyl" by itself or as part of another substituent refers
to an unsaturated branched, straight-chain or cyclic alkyl radical
having at least one carbon-carbon double bond derived by the
removal of one hydrogen atom from a single carbon atom of a parent
alkene. The group may be in either the cis or trans conformation
about the double bond(s). Typical alkenyl groups include, but are
not limited to, ethenyl; propenyls such as prop-1-en-1-yl,
prop-1-en-2-yl, prop-2-en-1-yl (allyl), prop-2-en-2-yl,
cycloprop-1-en-1-yl; cycloprop-2-en-1-yl; butenyls such as
but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl,
but-2-en-1-yl, but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl,
buta-1,3-dien-2-yl, cyclobut-1-en-1-yl, cyclobut-1-en-3-yl,
cyclobuta-1,3-dien-1-yl, etc.; and the like.
[0031] "Alkynyl" by itself or as part of another substituent refers
to an unsaturated branched, straight-chain or cyclic alkyl radical
having at least one carbon-carbon triple bond derived by the
removal of one hydrogen atom from a single carbon atom of a parent
alkyne. Typical alkynyl groups include, but are not limited to,
ethynyl; propynyls such as prop-1-yn-1-yl, prop-2-yn-1-yl, etc.;
butynyls such as but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.;
and the like.
[0032] "Acyl" by itself or as part of another substituent refers to
a radical --C(O)R.sup.30, where R.sup.30 is hydrogen, alkyl,
cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl,
heteroaryl, heteroarylalkyl as defined herein. Representative
examples include, but are not limited to formyl, acetyl,
cyclohexylcarbonyl, cyclohexylmethylcarbonyl, benzoyl,
benzylcarbonyl and the like.
[0033] "Alkoxy" by itself or as part of another substituent refers
to a radical --OR.sup.31 where R.sup.31 represents an alkyl or
cycloalkyl group as defined herein. Representative examples
include, but are not limited to, methoxy, ethoxy, propoxy, butoxy,
cyclohexyloxy and the like.
[0034] "Alkoxycarbonyl" by itself or as part of another
substituent, refers to a radical --C(O)OR.sup.31 where R.sup.31 is
as defined above.
[0035] "Aryl" by itself or as part of another substituent refers to
a monovalent aromatic hydrocarbon radical derived by the removal of
one hydrogen atom from a single carbon atom of a parent aromatic
ring system. Typical aryl groups include, but are not limited to,
groups derived from aceanthrylene, acenaphthylene,
acephenanthrylene, anthracene, azulene, benzene, chrysene,
coronene, fluoranthene, fluorene, hexacene, hexaphene, hexylene,
as-indacene, s-indacene, indane, indene, naphthalene, octacene,
octaphene, octalene, ovalene, penta-2,4-diene, pentacene,
pentalene, pentaphene, perylene, phenalene, phenanthrene, picene,
pleiadene, pyrene, pyranthrene, rubicene, triphenylene,
trinaphthalene and the like. Preferably, an aryl group comprises
from 6 to 20 carbon atoms, more preferably, from 6 to 12 carbon
atoms.
[0036] "Arylalkyl" by itself or as part of another substituent
refers to an acyclic alkyl radical in which one of the hydrogen
atoms bonded to a carbon atom, typically a terminal or sp.sup.3
carbon atom, is replaced with an aryl group. Typical arylalkyl
groups include, but are not limited to, benzyl, 2-phenylethan-1-yl,
2-phenylethen-1-yl, naphthylmethyl, 2-naphthylethan-1-yl,
2-naphthylethen-1-yl, naphthobenzyl, 2-naphthophenylethan-1-yl and
the like. Where specific alkyl moieties are intended, the
nomenclature arylalkanyl, arylalkenyl and/or arylalkynyl is used.
Preferably, an arylalkyl group is (C.sub.6-C.sub.30) arylalkyl,
e.g., the alkanyl, alkenyl or alkynyl moiety of the arylalkyl group
is (C.sub.1-C.sub.10) and the aryl moiety is (C.sub.6-C.sub.20),
more preferably, an arylalkyl group is (C.sub.6-C.sub.20)
arylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety of the
arylalkyl group is (C.sub.1-C.sub.8) and the aryl moiety is
(C.sub.6-C.sub.12).
[0037] "Carbamoyl" by itself or as part of another substituent
refers to the radical --C(O)N(R.sup.32)R.sup.33 where R.sup.32 and
R.sup.33 are independently hydrogen, alkyl, substituted alkyl,
aryl, substituted aryl, arylalkyl, substituted arylalkyl,
heteroarylalkyl, substituted heteroarylalkyl, heteroaryl or
substituted heteroaryl, as defined herein.
[0038] "Cycloalkyl" by itself or as part of another substituent
refers to a saturated or unsaturated cyclic alkyl radical. Where a
specific level of saturation is intended, the nomenclature
"cycloalkanyl" or "cycloalkenyl" is used. Typical cycloalkyl groups
include, but are not limited to, groups derived from cyclopropane,
cyclobutane, cyclopentane, cyclohexane, and the like. Preferably,
the cycloalkyl group is (C.sub.3-C.sub.10) cycloalkyl, more
preferably, (C.sub.3-C.sub.7) cycloalkyl.
[0039] "Cycloheteroalkyl" by itself or as part of another
substituent refers to a saturated or unsaturated cyclic alkyl
radical in which one or more carbon atoms (and any associated
hydrogen atoms) are independently replaced with the same or
different heteroatom. Typical heteroatoms to replace the carbon
atom(s) include, but are not limited to, N, P, O, S, Si, etc. Where
a specific level of saturation is intended, the nomenclature
"cycloheteroalkanyl" or "cycloheteroalkenyl" is used. Typical
cycloheteroalkyl groups include, but are not limited to, groups
derived from epoxides, azirines, thiiranes, imidazolidine,
morpholine, piperazine, piperidine, pyrazolidine, pyrrolidino,
quinuclidine and the like.
[0040] "Heteroalkyl Heteroalkanyl, Heteroalkenyl and Heteroalkynyl"
by themselves or as part of another substituent refer to alkyl,
alkanyl, alkenyl and alkynyl groups, respectively, in which one or
more of the carbon atoms (and any associated hydrogen atoms) are
independently replaced with the same or different heteroatomic
groups. Typical heteroatomic groups which can be included in these
groups include, but are not limited to, --O--, --S--, --O--O--,
--S--S--, --O--S--, --NR.sup.34R.sup.35--, .dbd.N--N.dbd.,
--N.dbd.N--, --N.dbd.N--NR.sup.36R.sup.37, --PR.sup.38--,
--P(O).sub.2--, --POR.sup.39--, --O--P(O).sub.2--, --SO--,
--SO.sub.2--, --SnR.sup.40R.sup.41-- and the like, where R.sup.34,
R.sup.35, R.sup.36, R.sup.37, R.sup.38, R.sup.39, R.sup.40 and
R.sup.41 are independently hydrogen, alkyl, substituted alkyl,
aryl, substituted aryl, arylalkyl, substituted arylalkyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl,
substituted heteroaryl, heteroarylalkyl or substituted
heteroarylalkyl.
[0041] "Heteroaryl" by itself or as part of another substituent
refers to a monovalent heteroaromatic radical derived by the
removal of one hydrogen atom from a single atom of a parent
heteroaromatic ring system. Typical heteroaryl groups include, but
are not limited to, groups derived from acridine, arsindole,
carbazole, .beta.-carboline, chromane, chromene, cinnoline, furan,
imidazole, indazole, indole, indoline, indolizine, isobenzofuran,
isochromene, isoindole, isoindoline, isoquinoline, isothiazole,
isoxazole, naphthyridine, oxadiazole, oxazole, perimidine,
phenanthridine, phenanthroline, phenazine, phthalazine, pteridine,
purine, pyran, pyrazine, pyrazole, pyridazine, pyridine,
pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline,
quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole,
thiophene, triazole, xanthene, and the like. Preferably, the
heteroaryl group is from 5-20 membered heteroaryl, more preferably
from 5-10 membered heteroaryl. Preferred heteroaryl groups are
those derived from thiophene, pyrrole, benzothiophene, benzofuran,
indole, pyridine, quinoline, imidazole, oxazole and pyrazine.
[0042] "Heteroarylalkyl" by itself or as part of another
substituent refers to an acyclic alkyl radical in which one of the
hydrogen atoms bonded to a carbon atom, typically a terminal or
sp.sup.3 carbon atom, is replaced with a heteroaryl group. Where
specific alkyl moieties are intended, the nomenclature
heteroarylalkanyl, heteroarylalkenyl and/or heterorylalkynyl is
used. In preferred embodiments, the heteroarylalkyl group is a 6-30
membered heteroarylalkyl, e.g., the alkanyl, alkenyl or alkynyl
moiety of the heteroarylalkyl is 1-10 membered and the heteroaryl
moiety is a 5-20-membered heteroaryl, more preferably, 6-20
membered heteroarylalkyl, e.g., the alkanyl, alkenyl or alkynyl
moiety of the heteroarylalkyl is 1-8 membered and the heteroaryl
moiety is a 5-12-membered heteroaryl.
[0043] "Parent Aromatic Ring System" refers to an unsaturated
cyclic or polycyclic ring system having a conjugated .pi. electron
system. Specifically included within the definition of "parent
aromatic ring system" are fused ring systems in which one or more
of the rings are aromatic and one or more of the rings are
saturated or unsaturated, such as, for example, fluorene, indane,
indene, phenalene, etc. Typical aromatic ring systems include, but
are not limited to, aceanthrylene, acenaphthylene,
acephenanthrylene, anthracene, azulene, benzene, chrysene,
coronene, fluoranthene, fluorene, hexacene, hexaphene, hexylene,
as-indacene, s-indacene, indane, indene, naphthalene, octacene,
octaphene, octalene, ovalene, penta-2,4-diene, pentacene,
pentalene, pentaphene, perylene, phenalene, phenanthrene, picene,
pleiadene, pyrene, pyranthrene, rubicene, triphenylene,
trinaphthalene and the like.
[0044] "Parent Heteroaromatic Ring System" refers to an aromatic
ring system in which one or more carbon atoms (and any associated
hydrogen atoms) are independently replaced with the same or
different heteroatom. Typical heteroatoms to replace the carbon
atoms include, but are not limited to, N, P, O, S, Si, etc.
Specifically included within the definition of "parent
heteroaromatic ring systems" are fused ring systems in which one or
more of the rings are aromatic and one or more of the rings are
saturated or unsaturated, such as, for example, arsindole,
benzodioxan, benzofuran, chromane, chromene, indole, indoline,
xanthene, etc. Typical heteroaromatic ring systems include, but are
not limited to, arsindole, carbazole, .beta.-carboline, chromane,
chromene, cinnoline, furan, imidazole, indazole, indole, indoline,
indolizine, isobenzofuran, isochromene, isoindole, isoindoline,
isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole,
oxazole, perimidine, phenanthridine, phenanthroline, phenazine,
phthalazine, pteridine, purine, pyran, pyrazine, pyrazole,
pyridazine, pyridine, pyrimidine, pyrrole, pyrrolizine,
quinazoline, quinoline, quinolizine, quinoxaline, tetrazole,
thiadiazole, thiazole, thiophene, triazole, xanthene, and the
like.
[0045] "Pharmaceutically acceptable salt" refers to a salt of a
compound of Formulae (I)-(III), which possesses the desired
pharmacological activity of the parent compound. Such salts
include: (1) acid addition salts, formed with inorganic acids such
as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,
phosphoric acid, and the like; or formed with organic acids such as
acetic acid, propionic acid, hexanoic acid, cyclopentanepropionic
acid, glycolic acid, pyruvic acid, lactic acid, malonic acid,
succinic acid, malic acid, maleic acid, fumaric acid, tartaric
acid, citric acid, benzoic acid, 3-(4-hydroxybenzoyl)benzoic acid,
cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic
acid, 1,2-ethane-disulfonic acid, 2-hydroxyethanesulfonic acid,
benzenesulfonic acid, 4-chlorobenzenesulfonic acid,
2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic
acid, 4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic acid,
glucoheptonic acid, 3-phenylpropionic acid, trimethylacetic acid,
tertiary butylacetic acid, lauryl sulfuric acid, gluconic acid,
glutamic acid, hydroxynaphthoic acid, salicylic acid, stearic acid,
muconic acid, and the like; or (2) salts formed when an acidic
proton present in the parent compound is replaced by a metal ion,
e.g., an alkali metal ion, an alkaline earth ion, or an aluminum
ion; or coordinates with an organic base such as ethanolamine,
diethanolamine, triethanolamine, N-methylglucamine and the
like.
[0046] "Pharmaceutically acceptable vehicle" refers to a diluent,
adjuvant, excipient or carrier with which a compound of Formulae
(I)-(III) is administered.
[0047] "Patient" includes humans. The terms "human" and "patient"
are used interchangeably herein.
[0048] "PEPT1" refers to an oligopeptide transporter protein that
normally absorbs dipeptides and tripeptides (and related
structures) in certain tissues, such as the intestine (Adibi, S.
A., Gastroenterology 1997, 113, 332-340; Leibach et al., Ann. Rev.
Nutr. 1996, 16, 99-119).
[0049] "Preventing" or "prevention" refers to a reduction in risk
of acquiring a disease or disorder (i.e., causing at least one of
the clinical symptoms of the disease not to develop in a patient
that may be exposed to or predisposed to the disease but does not
yet experience or display symptoms of the disease).
[0050] "Prodrug" refers to a derivative of a drug molecule that
requires a transformation within the body to release the active
drug. Prodrugs are frequently, although not necessarily,
pharmacologically inactive until converted to the parent drug. A
hydroxyl containing drug may be converted to, for example, to an
ester, carbonate, acyloxyalkyl or a sulfonate prodrug, which may be
hydrolyzed in vivo to provide the hydroxyl compound. Prodrugs for
drugs which functional groups different than those listed above are
well known to the skilled artisan.
[0051] "Promoiety" refers to a form of protecting group that when
used to mask a functional group within a drug molecule converts the
drug into a prodrug. Typically, the promoiety will be attached to
the drug via bond(s) that are cleaved by enzymatic or non-enzymatic
means in vivo.
[0052] "Protecting group" refers to a grouping of atoms that when
attached to a reactive functional group in a molecule masks,
reduces or prevents reactivity of the functional group. Examples of
protecting groups can be found in Green et al., "Protective Groups
in Organic Chemistry", (Wiley, 2.sup.nd ed. 1991) and Harrison et
al., "Compendium of Synthetic Organic Methods", Vols. 1-8 (John
Wiley and Sons, 1971-1996). Representative amino protecting groups
include, but are not limited to, formyl, acetyl, trifluoroacetyl,
benzyl, benzyloxycarbonyl ("CBz"), tert-butoxycarbonyl ("Boc"),
trimethylsilyl ("TMS"), 2-trimethylsilyl-ethanesulfonyl ("SES"),
trityl and substituted trityl groups, allyloxycarbonyl,
9-fluorenylmethyloxycarbonyl ("FMOC"), nitro-veratryloxycarbonyl
("NVOC") and the like. Representative hydroxy protecting groups
include, but are not limited to, those where the hydroxy group is
either acylated or alkylated such as benzyl, and trityl ethers as
well as alkyl ethers, tetrahydropyranyl ethers, trialkylsilyl
ethers and allyl ethers.
[0053] "Substituted" refers to a group in which one or more
hydrogen atoms are independently replaced with the same or
different substituent(s). Typical substituents include, but are not
limited to, -M, --R.sup.60, --O--, .dbd.O, --OR.sup.60,
--SR.sup.60, --S.sup.-, .dbd.S, --NR.sup.60R.sup.61,
.dbd.NR.sup.60, --CF.sub.3, --CN, --OCN, --SCN, --NO, --NO.sub.2,
.dbd.N.sub.2, --N.sub.3, --S(O).sub.2O.sup.-, --S(O).sub.2OH,
--S(O).sub.2R.sup.60, --OS(O.sub.2)O.sup.-, --OS(O).sub.2R.sup.60,
--P(O)(O--).sub.2, --P(O)(OR.sup.60)(O.sup.-),
--OP(O)(OR.sup.60)(OR.sup.61), --C(O)R.sup.60, --C(S)R.sup.60,
--C(O)OR.sup.60, --C(O)NR.sup.60R.sup.61, --C(O)O.sup.-,
--C(S)OR.sup.60, --NR.sup.62C(O)NR.sup.60R.sup.61,
--NR.sup.62C(S)NR.sup.60R.sup.61,
--NR.sup.62C(NR.sup.63)NR.sup.60R.sup.61 and
--C(NR.sup.62)NR.sup.60R.sup.61 where M is independently a halogen;
R.sup.60, R.sup.61, R.sup.62 and R.sup.63 are independently
hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, aryl, substituted aryl, heteroaryl or substituted
heteroaryl, or optionally R.sup.60 and R.sup.61 together with the
nitrogen atom to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring; and R.sup.64 and R.sup.65 are
independently hydrogen, alkyl, substituted alkyl, aryl, cycloalkyl,
substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, aryl, substituted aryl, heteroaryl or substituted
heteroaryl, or optionally R.sup.64 and R.sup.65 together with the
nitrogen atom to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring. Preferably, substituents include
-M, --R.sup.60, .dbd.O, --OR.sup.60, --SR.sup.60, --S.sup.-,
.dbd.S, --NR.sup.60R.sup.61, .dbd.NR.sup.60, --CF.sub.3, --CN,
--OCN, --SCN, --NO, --NO.sub.2, .dbd.N.sub.2, --N.sub.3,
--S(O).sub.2R.sup.60, --OS(O.sub.2)O.sup.-, --OS(O).sub.2R.sup.60,
--P(O)(O.sup.-).sub.2, --P(O)(OR.sup.60)(O.sup.-),
--OP(O)(OR.sup.60)(OR.sup.61), --C(O)R.sup.60, --C(S)R.sup.60,
--C(O)OR.sup.60, --C(O)NR.sup.60R.sup.61, --C(O)O.sup.-,
--NR.sup.62C(O)NR.sup.60R.sup.61, more preferably, -M, --R.sup.60,
.dbd.O, --OR.sup.60, --SR.sup.60, --NR.sup.60R.sup.61, --CF.sub.3,
--CN, --NO.sub.2, --S(O).sub.2R.sup.60, --P(O)(OR.sup.60)(O.sup.-),
--OP(O)(OR.sup.60)(OR.sup.61), --C(O)R.sup.60, --C(O)OR.sup.60,
--C(O)NR.sup.60R.sup.61, --C(O)O.sup.-, most preferably, -M,
--R.sup.60, .dbd.O, --OR.sup.60, --SR.sup.60, --NR.sup.60R.sup.61,
--CF.sub.3, --CN, --NO.sub.2, --S(O).sub.2R.sup.60,
--OP(O)(OR.sup.60)(OR.sup.61), --C(O)R.sup.60, --C(O)OR.sup.60,
--C(O)O.sup.-, where R.sup.60, R.sup.61 and R.sup.62 are as defined
above.
[0054] "Transported by the PEPT1 transporter" refers to the
translocation of a molecule across a membrane of a cell expressing
the PEPT1 transporter. The translocation occurs through interaction
with the transporter and is energized by cotransport of H.sup.+
ions across the membrane.
[0055] "Treating" or "treatment" of any disease or disorder refers
to one or more of the following: (1) ameliorating the disease or
disorder (i.e., arresting or reducing the development of the
disease or at least one of the clinical symptoms thereof); (2)
ameliorating at least one physical parameter, which may not be
discernible by the patient; (3) inhibiting the disease or disorder,
either physically, (e.g., stabilization of a discernible symptom),
physiologically, (e.g., stabilization of a physical parameter), or
both; and (4) delaying the onset of the disease or disorder.
[0056] "Therapeutically effective amount" means the amount of a
compound or composition that, when administered to a patient, is
sufficient to effect the desired therapy. The "therapeutically
effective amount" will vary depending on the compound, the disease
and its severity and the age, weight, etc., of the patient to be
treated.
[0057] Reference will now be made in detail to certain compounds
and methods of making and administering these compounds. The
invention is not limited to those compounds and methods but rather
is defined by the claim(s) issuing herefrom.
4.2 Compounds
[0058] The compounds disclosed herein are prodrugs of propofol. A
first class of propofol prodrugs including compounds of structural
Formula (I) is provided:
##STR00003##
[0059] or a pharmaceutically acceptable salt, hydrate, solvate or
N-oxide thereof, wherein:
[0060] R.sup.1 is selected from the group consisting of hydrogen,
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--, R.sup.6--, R.sup.6C(O)-- and
R.sup.6OC(O)--;
[0061] R.sup.2 is --OR.sup.7 or
--[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7];
[0062] p and q are independently 1 or 2;
[0063] each R.sup.4 is independently selected from the group
consisting of hydrogen, alkyl, substituted alkyl, alkoxy,
substituted alkoxy, acyl, substituted acyl, alkoxycarbonyl,
substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, carbamoyl, substituted carbamoyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl,
substituted heteroaryl, heteroarylalkyl and substituted
heteroarylalkyl, or optionally, when R.sup.4 and R.sup.5 are
attached to adjacent atoms then R.sup.4 and R.sup.5 together with
the atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring;
[0064] R.sup.5 is selected from the group consisting of hydrogen,
R.sup.6--, R.sup.6C(O)-- and R.sup.6OC(O)--;
[0065] R.sup.6 is selected from the group consisting of alkyl,
substituted alkyl, aryl, substituted aryl, arylalkyl, substituted
arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,
heteroaryl, substituted heteroaryl and heteroarylalkyl;
[0066] R.sup.7 is selected from the group consisting of hydrogen,
alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, cycloalkyl, substituted cycloalkyl,
cycloheteroalkyl, heteroaryl, substituted heteroaryl and
heteroarylalkyl;
[0067] R.sup.8 is selected from the group consisting of hydrogen,
alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, heteroaryl,
substituted heteroaryl and heteroarylalkyl;
[0068] each R.sup.9 is independently selected from the group
consisting of hydrogen, alkyl, substituted alkyl, alkoxy,
substituted alkoxy, acyl, substituted acyl, alkoxycarbonyl,
substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,
substituted arylalkyl, carbamoyl, substituted carbamoyl,
cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substituted
cycloheteroalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl,
substituted heteroaryl, heteroarylalkyl and substituted
heteroarylalkyl, or optionally, when R.sup.8 and R.sup.9 are
attached to adjacent atoms then R.sup.8 and R.sup.9 together with
the atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring;
[0069] with the proviso that when R.sup.2 is
--[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7] then R.sup.1 is not
[R.sup.5NH(CHR.sup.4).sub.pC(O)]--.
[0070] In some embodiments, a compound of Formula (I) is derived
from .alpha.-amino acids (e.g., [H.sub.2N(CHR.sup.4)C(O)OH] and/or
[HNR.sup.8(CHR.sup.9)C(O)OH]) including, but not limited to, the 20
genetically encoded amino acids and the non-coded amino acids such
as, for example, 2,3-diaminobutyric acid, 2,4-diaminobutyric acid,
hydroxylysine, homoserine, homoarginine, homotyrosine,
homocysteine, homophenylalanine, citrulline, sarcosine, orthinine,
N-methylleucine, kynurenine, penicillamine, 4-aminophenylalanine,
3-(2-naphthyl)alanine, 3-(1-naphthyl)alanine, methionine sulfone,
methionine sulfoxide, t-butylalanine, 4-hydroxyphenylglycine,
aminoalanine, 1,2,3,4 tetrahydrorisoquinoline-3-carboxylic acid,
vinylalanine, propargylglycine, 1,2,4-triazolo-3-alanine,
4,4,4-trifluoro-threonine, thyronine, 6-hydroxytryptophan,
5-hydroxytryptophan, 3-hydroxykynurenine, 3-aminotyrosine,
trifluoromethylalanine (2-(4-pyridyl)ethyl)cysteine,
3,4-dimethoxy-phenylalanine, 3-(2-thiazolyl)alanine, ibotenic acid,
quisqualic acid, 3-trifluoromethylphenylalanine,
4-trifluoromethylphenylalanine, t-butylglycine, cyclopentylglycine,
cyclohexylglycine, phenylglycine, cyclohexylalanine, thiohistidine,
3-methoxytyrosine, norleucine, norvaline, alloisoleucine,
thioproline, dehydroproline, hydroxyproline, isonipectotic acid,
homoproline, N-acetyl lysine, aminophenylbutyric acid,
phenylalanines substituted at the ortho, meta or para position of
the phenyl moiety with one or two of the following: a
(C.sub.1-C.sub.4) alkyl, a (C.sub.1-C.sub.4) alkoxy, halogen or
nitro groups or substituted with a methylenedioxy group, .beta.-2-
and 3-thienylalanine, .beta.-2- and 3-furanylalanine, 2-, 3- and
4-pyridylalanine, .beta.-(benzothienyl-2- and 3-yl)alanine,
.beta.-(1- and 2-naphthyl)alanine, O-sulfate, O-phosphate and
O-carboxylate esters of tyrosine, 3-sulfo-tyrosine,
3-carboxy-tyrosine, 3-phospho-tyrosine, 4-methane sulfonic acid
ester of tyrosine, 4-methane phosphonic acid ester of tyrosine,
3,5-diiodotyrosine or 3-nitrotyrosine.
[0071] In other embodiments of a compound of Formula (I), R.sup.1
is hydrogen or [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, where p is 1.
Preferably, R.sup.4 is hydrogen, alkanyl, substituted alkanyl,
aryl, substituted aryl, arylalkanyl, substituted arylalkanyl,
cycloalkanyl, heteroarylalkanyl or substituted heteroarylalkanyl,
or optionally, R.sup.4 and R.sup.5 together with the atoms to which
they are bonded form a cycloheteroalkyl or substituted
cycloheteroalkyl ring.
[0072] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1, R.sup.5 is
hydrogen and R.sup.4 is hydrogen, alkanyl or cycloalkanyl.
Preferably, R.sup.4 is hydrogen, methyl, isopropyl, isobutyl,
sec-butyl, t-butyl, cyclopentyl or cyclohexyl.
[0073] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1, R.sup.5 is
hydrogen, and R.sup.4 is substituted alkanyl. Preferably, R.sup.4
is --CH.sub.2OH, --CH(OH)CH.sub.3, --CH.sub.2CO.sub.2H,
--CH.sub.2CH.sub.2CO.sub.2H, --CH.sub.2CONH.sub.2,
--CH.sub.2CH.sub.2CONH.sub.2, --CH.sub.2CH.sub.2SCH.sub.3,
--CH.sub.2SH, --CH.sub.2(CH.sub.2).sub.3NH.sub.2 or
--CH.sub.2CH.sub.2CH.sub.2NHC(NH)NH.sub.2.
[0074] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1, R.sup.5 is
hydrogen, and R.sup.4 is aryl, arylalkanyl, substituted arylalkanyl
or heteroarylalkanyl. Preferably, R.sup.4 is phenyl, benzyl,
4-hydroxybenzyl, 4-imidazolylmethyl or 3-indolylmethyl
[0075] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1 and R.sup.4
and R.sup.5 together with the atoms to which they are bonded form a
cycloheteroalkyl or substituted cycloheteroalkyl ring. Preferably
R.sup.4 and R.sup.5 together with the atoms to which they are
bonded form an azetidine, pyrrolidine or piperidine ring.
[0076] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1, R.sup.4 is
hydrogen, alkanyl, substituted alkanyl, aryl, substituted aryl,
arylalkanyl, substituted arylalkanyl, cycloalkanyl,
heteroarylalkanyl or substituted heteroarylalkanyl, R.sup.5 is
R.sup.6--, R.sup.6C(O)-- or R.sup.6OC(O)-- and R.sup.6 is alkyl,
substituted alkyl, aryl, substituted aryl, arylalkyl, substituted
arylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,
heteroaryl, substituted heteroaryl or heteroarylalkyl. Preferably,
R.sup.6 is C.sub.1-4 alkyl, phenyl, substituted phenyl, benzyl or
substituted benzyl.
[0077] In still other embodiments of a compound of Formula (I),
R.sup.1 is hydrogen or [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, where p
is 2. Preferably, R.sup.4 is hydrogen, alkanyl, substituted
alkanyl, aryl, substituted aryl, arylalkanyl, substituted
arylalkanyl, cycloalkanyl, heteroarylalkanyl or substituted
heteroarylalkanyl, or optionally, when R.sup.4 and R.sup.5 are
attached to adjacent atoms then R.sup.4 and R.sup.5 together with
the atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring.
[0078] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 2 and R.sup.4
is hydrogen, alkanyl, substituted alkanyl, aryl, substituted aryl,
arylalkanyl, substituted arylalkanyl, cycloalkanyl,
heteroarylalkanyl or substituted heteroarylalkanyl. Preferably,
R.sup.4 is hydrogen, C.sub.1-4 alkyl, cyclopentyl, cyclohexyl,
phenyl, substituted phenyl, benzyl or substituted benzyl.
[0079] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 2, R.sup.5 is
hydrogen and R.sup.4 is hydrogen, C.sub.1-4 alkyl, cyclopentyl,
cyclohexyl, phenyl, substituted phenyl, benzyl or substituted
benzyl.
[0080] In still other embodiments of a compound of Formula (I),
R.sup.2 is --OR.sup.7 and R.sup.7 is hydrogen, alkyl, aryl,
substituted aryl, arylalkyl or substituted arylalkyl. Preferably,
R.sup.7 is hydrogen, C.sub.1-4 alkyl, phenyl, substituted phenyl,
benzyl or substituted benzyl.
[0081] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl. Preferably, R.sup.7 is hydrogen, C.sub.1-4
alkyl, phenyl, substituted phenyl, benzyl or substituted
benzyl.
[0082] In still other embodiments of a compound of Formula (I),
R.sup.2 is [NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1, R.sup.8
is hydrogen and R.sup.9 is hydrogen, alkanyl, substituted alkanyl,
aryl, substituted aryl, arylalkanyl, substituted arylalkanyl,
cycloalkanyl, heteroarylalkanyl or substituted heteroarylalkanyl.
Preferably, R.sup.7 hydrogen, alkyl, aryl, substituted aryl,
arylalkyl or substituted arylalkyl, more preferably, R.sup.7 is
hydrogen, C.sub.1-4 alkyl, phenyl, substituted phenyl, benzyl or
substituted benzyl.
[0083] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl, R.sup.8 is hydrogen and R.sup.9 is hydrogen,
alkanyl or cycloalkanyl. Preferably, R.sup.9 is hydrogen, methyl,
isopropyl, isobutyl, sec-butyl, t-butyl, cyclopentyl or cyclohexyl.
Preferably, R.sup.7 is hydrogen, C.sub.1-4 alkyl, phenyl,
substituted phenyl, benzyl or substituted benzyl.
[0084] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl, R.sup.8 is hydrogen and R.sup.9 is
substituted alkanyl. Preferably, R.sup.9 is --CH.sub.2OH,
--CH(OH)CH.sub.3, --CH.sub.2CO.sub.2H, --CH.sub.2CH.sub.2CO.sub.2H,
--CH.sub.2CONH.sub.2, --CH.sub.2CH.sub.2CONH.sub.2,
--CH.sub.2CH.sub.2SCH.sub.3, --CH.sub.2SH,
--CH.sub.2(CH.sub.2).sub.3NH.sub.2 or
--CH.sub.2CH.sub.2CH.sub.2NHC(NH)NH.sub.2. Preferably, R.sup.7 is
hydrogen, C.sub.1-4 alkyl, phenyl, substituted phenyl, benzyl or
substituted benzyl.
[0085] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl, R.sup.8 is hydrogen and R.sup.9 is aryl,
arylalkanyl, substituted arylalkanyl or heteroarylalkanyl.
Preferably, R.sup.9 is phenyl, benzyl, 4-hydroxybenzyl,
4-imidazolylmethyl or 3-indolylmethyl. Preferably R.sup.7 is
hydrogen, C.sub.1-4 alkyl, phenyl, substituted phenyl, benzyl or
substituted benzyl.
[0086] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 1,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl and R.sup.8 and R.sup.9 together with the
atoms to which they are bonded form a cycloheteroalkyl or
substituted cycloheteroalkyl ring. Preferably R.sup.8 and R.sup.9
together with the atoms to which they are bonded form an azetidine,
pyrrolidine or piperidine ring. Preferably, R.sup.7 is hydrogen,
C.sub.1-4 alkyl, phenyl, substituted phenyl, benzyl or substituted
benzyl.
[0087] In still other embodiments of a compound of Formula (I),
R.sup.2 is --[NR.sup.8(CHR.sup.9).sub.qC(O)OR.sup.7], q is 2,
R.sup.7 is hydrogen, alkyl, aryl, substituted aryl, arylalkyl or
substituted arylalkyl and R.sup.9 is hydrogen, alkanyl, substituted
alkanyl, aryl, substituted aryl, arylalkanyl, substituted
arylalkanyl, cycloalkanyl, heteroarylalkanyl or substituted
heteroarylalkanyl. Preferably, R.sup.7 is hydrogen, C.sub.1-4
alkyl, phenyl, substituted phenyl, benzyl or substituted benzyl.
Preferably, R.sup.8 is hydrogen and R.sup.9 is hydrogen, C.sub.1-4
alkyl, cyclopentyl, cyclohexyl, phenyl, substituted phenyl, benzyl
or substituted benzyl.
[0088] In still other embodiments of a compound of Formula (I),
R.sup.1 is [R.sup.5NH(CHR.sup.4).sub.pC(O)]--, p is 1, R.sup.5 is
hydrogen and R.sup.2 is --OH to provide a compound of Formula
(II):
##STR00004##
or a pharmaceutically acceptable salt, hydrate, solvate or N-oxide
thereof, wherein R.sup.4 is hydrogen, alkanyl, substituted alkanyl,
aryl, substituted aryl, arylalkanyl, substituted arylalkanyl,
cycloalkanyl, heteroarylalkanyl or substituted
heteroarylalkanyl.
[0089] In some embodiments of a compound of Formula (II), R.sup.4
is hydrogen, alkanyl or cycloalkanyl. Preferably, R.sup.4 is
hydrogen, methyl, isopropyl, isobutyl, sec-butyl, t-butyl,
cyclopentyl or cyclohexyl.
[0090] In other embodiments of a compound of Formula (II), R.sup.4
is substituted alkanyl. Preferably, R.sup.4 is --CH.sub.2OH,
--CH(OH)CH.sub.3, --CH.sub.2CO.sub.2H, --CH.sub.2CH.sub.2CO.sub.2H,
--CH.sub.2CONH.sub.2, --CH.sub.2CH.sub.2CONH.sub.2,
--CH.sub.2CH.sub.2SCH.sub.3, --CH.sub.2SH,
--CH.sub.2(CH.sub.2).sub.3NH.sub.2 or
--CH.sub.2CH.sub.2CH.sub.2NHC(NH)NH.sub.2.
[0091] In still other embodiments of a compound of Formula (II),
R.sup.4 is aryl, arylalkanyl, substituted arylalkanyl or
heteroarylalkanyl. Preferably, R.sup.4 is phenyl, benzyl,
4-hydroxybenzyl, 4-imidazolylmethyl or 3-indolylmethyl.
[0092] In still other embodiments of a compound of Formula (II),
the .alpha.-carbon of the N-terminal amino acid residue is of the
L-configuration. In still other embodiments of a compound of
Formula (II), the .alpha.-carbon of the N-terminal amino acid
residue is of the D-configuration. In still other embodiments of a
compound of Formula (II), the .alpha.-carbon of the C-terminal
amino acid residue is of the L-configuration. In still other
embodiments of a compound of Formula (II), the .alpha.-carbon of
the C-terminal amino acid residue is of the D-configuration. In
still other embodiments of a compound of Formula (II), the
.alpha.-carbons of both the N- and C-terminal amino acid residues
are of the L-configuration.
[0093] In still other embodiments of a compound of Formula (I),
R.sup.1 is hydrogen and R.sup.2 is --OH to provide a compound of
Formula (III):
##STR00005##
[0094] or a pharmaceutically acceptable salt, hydrate or solvate
thereof.
[0095] In some embodiment of a compound of Formula (III), the
.alpha.-carbon of the amino acid residue is of the L-configuration.
In other embodiments of a compound of Formula (III), the
.alpha.-carbon of the amino acid residue is of the
D-configuration.
[0096] Compounds disclosed herein may be identified either by their
chemical structure and/or chemical name. When the chemical
structure and chemical name conflict, the chemical structure is
determinative of the identity of the compound.
[0097] Compounds described herein may contain one or more chiral
centers and/or double bonds and therefore, may exist as
stereoisomers, such as double-bond isomers (i.e., geometric
isomers), enantiomers or diastereomers. Accordingly, when
stereochemistry at chiral centers is not specified, the chemical
structures depicted herein encompass all possible configurations at
those chiral centers including the stereoisomerically pure form
(e.g., geometrically pure, enantiomerically pure or
diastereomerically pure) and enantiomeric and stereoisomeric
mixtures. Enantiomeric and stereoisomeric mixtures can be resolved
into their component enantiomers or stereoisomers using separation
techniques or chiral synthesis techniques well known to the skilled
artisan. Compounds disclosed herein may also exist in several
tautomeric forms including the enol form, the keto form and
mixtures thereof. Accordingly, the chemical structures depicted
herein encompass all possible tautomeric forms of the illustrated
compounds.
[0098] Compounds disclosed herein also include isotopically labeled
compounds where one or more atoms have an atomic mass different
from the atomic mass conventionally found in nature. Examples of
isotopes that may be incorporated into the compounds include, but
are not limited to, .sup.2H, .sup.3H, .sup.11C, .sup.13C, .sup.14C,
.sup.15N, .sup.17O and .sup.18O.
[0099] Compounds disclosed herein may exist in unsolvated forms as
well as solvated forms, including hydrated forms and as N-oxides.
In general, the hydrated, solvated and N-oxide forms are within the
scope of the present invention. Certain compounds may exist in
multiple crystalline or amorphous forms. In general, all physical
forms are equivalent for the uses contemplated herein and are
intended to be within the scope of the present disclosure. Further,
it should be understood, when partial structures of the compounds
are illustrated, that brackets indicate the point of attachment of
the partial structure to the rest of the molecule.
[0100] Compounds of structural Formulae (I)-(III) may be
administered orally and transported across cells (i.e.,
enterocytes) lining the lumen of the gastrointestinal tract. While
not wishing to be bound by any particular transport mechanism, some
of the compounds of structural Formulae (I)-(III) may be substrates
for the proton-coupled intestinal peptide transport system
("PEPT1") (Leibach et al., Annu. Rev. Nutr. 1996, 16, 99-119)
which, typically mediates the cellular uptake of small intact
peptides consisting of two or three amino acids that are derived
from the digestion of dietary proteins. In the intestine, where
small peptides are not effectively absorbed by passive diffusion,
PEPT1 may act as a vehicle for their effective uptake across the
apical membrane of the gastric mucosa.
[0101] Methods for determining whether compounds of Formulae
(I)-(III) serve as substrates for the PEPT1 transporter are
disclosed in Example 23 herein (see Section 5). In vitro systems,
which use cells engineered to heterologously express the transport
system, or cell-lines that endogenously express the transporter
(e.g. Caco-2 cells) may be used to assay transport of compounds of
Formulae (I)-(III) by PEPT1 transporter. Standard methods for
evaluating the enzymatic conversion of propofol prodrug compounds
to propofol in vitro are disclosed in Example 24 herein.
[0102] Oral administration of propofol prodrug compounds to monkeys
is described in Example 25, and illustrates that actively
transported prodrugs can afford significant enhancements in oral
bioavailability of propofol.
4.3 Synthesis of Propofol Prodrug Compounds
[0103] The compounds of Formulae (I)-(III) may be obtained via the
synthetic methods illustrated in Schemes 1-3. Starting materials
useful for preparing these compounds and intermediates thereof are
commercially available or can be prepared by well-known synthetic
methods (Harrison et al., "Compendium of Synthetic Organic
Methods", Vols. 1-8 (John Wiley and Sons, 1971-1996); "Beilstein
Handbook of Organic Chemistry," Beilstein Institute of Organic
Chemistry, Frankfurt, Germany; Feiser et al., "Reagents for Organic
Synthesis," Volumes 1-17, Wiley Interscience; Trost et al.,
"Comprehensive Organic Synthesis," Pergamon Press, 1991;
"Theilheimer's Synthetic Methods of Organic Chemistry," Volumes
1-45, Karger, 1991; March, "Advanced Organic Chemistry," Wiley
Interscience, 1991; Larock "Comprehensive Organic Transformations,"
VCH Publishers, 1989; Paquette, "Encyclopedia of Reagents for
Organic Synthesis," John Wiley & Sons, 1995). Other methods for
synthesis of the compounds described herein and/or starting
materials are either described in the art or will be readily
apparent to the skilled artisan. Accordingly, the methods presented
in Schemes 1-2 herein are illustrative rather than
comprehensive.
[0104] Amino acid building blocks useful for the preparation of
compounds of Formulae (I)-(III) typically incorporate one or more
protecting groups. Non-limiting examples of useful protecting
groups for the nitrogen atom of such amino acids include
tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (CBz) and
9-fluorenylmethyloxycarbonyl (Fmoc) moieties, while those for the
carboxyl group include tert-butyl, benzyl and 9-fluorenylmethyl
esters. Amino acids of either L- or D-stereochemistry may be used
in these reactions. The threonine moiety in compounds of Formula
(I)-(III) may be derived from L-threonine, D-threonine, or the
epimeric analogs L-allothreonine and D-allothreonine.
[0105] Propofol (1) is converted to the chloroformate derivative
(2) by treatment with a phosgene equivalent as illustrated in
Scheme 1.
##STR00006##
[0106] One method for the preparation of compounds of Formula (I)
where R.sup.1 is [H.sub.2N(CHR)C(O)]- and R.sup.2 is OH, i.e.,
compound (8), is illustrated in Scheme 2. Protected threonine
derivative (3) is treated with chloroformate (2) in the presence of
a base (e.g. a tertiary amine) to afford intermediate (4), which
upon deprotection affords compound (5). Acylation with protected
amino acid (6) following to standard peptide coupling protocols
yields intermediate (7), which is deprotected to afford the
dipeptide propofol carbonate compound (8).
##STR00007##
[0107] Another method for the preparation of compounds of Formula
(I) where R.sup.1 is [H.sub.2N(CHR)C(O)]- and R.sup.2 is OH, i.e.,
compound (8), is illustrated in Scheme 3. The protected threonine
dipeptide (9) is reacted with chloroformate (2) and further
deprotected to afford compound (8).
##STR00008##
[0108] A compound of Formula (I) where R.sup.1 is hydrogen and
R.sup.2 is OH, i.e. a compound of Formula (III), is prepared by
removal of the carboxyl protecting group from compound (5).
4.4 Therapeutic/Prophylactic Uses and Methods of Administration
[0109] The compounds of Formulae (I)-(III), as described herein,
may be used to treat and/or prevent migraine in patients. The
methods comprise administering to a patient a therapeutically
effective amount of a compound of Formulae (I)-(III) to treat
and/or prevent migraine. In the therapeutic methods herein, a
therapeutically effective amount of the compound is administered to
a patient suffering from a migraine headache. In the prophylactic
methods herein, a therapeutically effective amount of the compound
is administered to a patient at risk of developing a migraine.
[0110] In some embodiments, the compounds are administered orally
to treat and/or prevent migraine. However, in other embodiments,
the compounds are administered parenterally (e.g., via inhalation
or injection). In some embodiments, the compounds are administered
in amounts of between about 10 mg to about 4 g to treat or prevent
migraine.
[0111] The compounds of Formulae (I)-(III) may also be used as
anti-emetics and can be administered to patients at risk of
vomiting and/or who are nauseous. For example, the compounds may be
administered to patients that are being concurrently treated with
various chemotherapy agents and/or surgical procedures, which
induce nausea, in order to treat and/or prevent nausea and
vomiting. Typically, a therapeutically effective amount of the
compound is administered to a patient to treat and/or prevent
nausea and vomiting.
[0112] In some embodiments, the compounds are administered orally
to treat and/or prevent nausea or vomiting. However, in other
embodiments, the compounds are administered parenterally (e.g., via
inhalation or injection to treat and/or prevent nausea or vomiting.
In some embodiments, the compounds are administered in amounts of
between about 10 mg to about 4 g to treat and/or prevent nausea or
vomiting.
[0113] The compounds of Formulae (I)-(III) may also be used as
hypnotic agents to induce and/or maintain general anesthesia and/or
as a sedative. Typically, a therapeutically effective amount of the
compound is administered to a patient to induce hypnosis,
anesthesia and/or sedation.
[0114] In some embodiments, the compounds are administered
intravenously when used as a general anesthetic. In other
embodiments, the compounds are administered by inhalation. The
compounds may be formulated by methods used to formulate propofol,
which are well known in the art. In some embodiments, compounds of
Formulae (I)-(III) that are water soluble may be formulated as an
injectable aqueous solution, which contains significantly less
emulsifiers or solubilizers than used in aqueous formulations of
propofol, thereby avoiding discomfort at the site of injection.
[0115] In some embodiments, the compounds are administered orally
in amounts of about 10 mg to 4 g daily when used as a sedative
(e.g., for the treatment of anxiety conditions). However, in other
embodiments, the compounds may also be administered by inhalation,
intravenously or intramuscularly when used as a sedative.
[0116] The compounds of Formulae (I)-(III) may be administered in
similar amounts and in the same schedule as described in the art
for propofol. In one embodiment, dosage levels of the compounds of
Formulae (I)-(III) for producing general anesthesia, maintaining
anesthesia and producing a sedative effect are as described in the
art for propofol.
[0117] The compounds of Formulae (I)-(III) may also be used to
inhibit oxidation in biological materials. The methods involve
contacting the biological material with an effective amount of the
compound. In therapeutic methods herein, a therapeutically
effective amount of the compound is administered to a patient
suffering from a pathological condition treated by inhibition of
oxidation. In prophylactic methods herein, a therapeutically
effective amount of the compound is administered to a patient at
risk of developing a disease as a result of exposure to oxidative
stress. The compounds may find particular use in preventing and/or
treating oxidation in disorders of the central nervous system that
involve an inflammatory component.
[0118] The compounds of Formulae (I)-(III) may be used to treat
and/or prevent neurodegenerative conditions of the nervous system,
which include, but are not limited to, Friedrich's disease,
Parkinson's disease, Alzheimer's disease, Huntington's disease,
amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS) and
Pick disease. In some embodiments, a therapeutically effective
amount of a compound (e.g., between about 10 mg to about 4 g daily)
is orally administered to treat and/or prevent chronic
neurodegenerative diseases.
[0119] The compounds of Formulae (I)-(III) may also be used to
treat and/or prevent trauma to the central nervous system such as,
for example, skull fracture and its resulting edema, concussion,
contusion, brain hemorrhages, shearing lesions, subdural and
epidural hematoma, and spinal cord injury (e.g., mechanical injury
due to compression or flexion of the spinal cord). In some
embodiments, a compound is parenterally administered by intravenous
injection or injection directly into the central nervous system
(i.e., intrathecally ("IT") or into the brain) to treat and/or
prevent traumatic conditions of the central nervous system. In
other embodiments, a therapeutically effective amount of a compound
(e.g., between about 25 mg to about 500 mg IV or IM and between
about 5 mg to about 100 mg IT) are administered to treat and/or
prevent traumatic conditions of the central nervous system.
[0120] The compounds of Formulae (I)-(III) may also be used as
anti-convulsives to treat and/or prevent seizures (e.g., epileptic
seizures). Methods for treating and/or preventing convulsions
comprise administering a therapeutically effective amount of a
compound to a patient in need of such treatment. In one embodiment,
the compounds are administered orally to treat and/or prevent
convulsions. In another embodiment, the compounds are parenterally
administered to treat and/or prevent convulsions. In still other
embodiments, the compounds are administered in amounts of between
about 10 mg to about 4 g daily to treat and/or prevent
convulsions.
[0121] When used to treat and/or prevent the above disease or
disorders compounds and/or pharmaceutical compositions of Formulae
(I)-(III) may be administered or applied singly, or in combination
with other agents. The compounds and/or compositions may also be
administered or applied singly, or in combination with other
pharmaceutically active agents, including other compounds of
Formulae (I)-(III).
[0122] Provided herein are methods of treatment and prophylaxis by
administering to a patient a therapeutically effective amount of a
composition or compound of Formulae (I)-(III). The patient may be
an animal, is more preferably, a mammal and even more preferably, a
human.
[0123] The compounds of Formulae (I)-(III) and/or pharmaceutical
compositions thereof are preferably administered orally. The
compounds and/or pharmaceutical compositions thereof may also be
administered by any other convenient route, for example, by
infusion or bolus injection, by absorption through epithelial or
mucocutaneous linings (e.g., oral mucosa, rectal and intestinal
mucosa, etc.). Administration can be systemic or local. Various
delivery systems are known, (e.g., encapsulation in liposomes,
microparticles, microcapsules, capsules, etc.) that can be used to
administer a compound and/or pharmaceutical composition. Methods of
administration include, but are not limited to, intradermal,
intramuscular, intraperitoneal, intravenous, subcutaneous,
intranasal, epidural, oral, sublingual, intranasal, intracerebral,
intravaginal, transdermal, rectally, by inhalation, or topically,
particularly to the ears, nose, eyes, or skin.
[0124] In specific embodiments, it may be desirable to administer
one or more compounds and/or pharmaceutical compositions thereof
locally to the area in need of treatment. This may be achieved, for
example, and not by way of limitation, by local infusion during
surgery, topical application, e.g., in conjunction with a wound
dressing after surgery, by injection, by means of a catheter, by
means of a suppository, or by means of an implant, said implant
being of a porous, non-porous, or gelatinous material, including
membranes, such as sialastic membranes or fibers. In one
embodiment, administration can be by direct injection at the site
(or former site) of cancer or arthritis.
[0125] In certain embodiments, it may be desirable to introduce one
or more compounds and/or pharmaceutical compositions thereof into
the central nervous system by any suitable route, including
intraventricular, intrathecal and epidural injection.
Intraventricular injection may be facilitated by an
intraventricular catheter, for example, attached to a reservoir,
such as an Ommaya reservoir.
[0126] In some embodiments, the compounds and/or pharmaceutical
compositions can be delivered via sustained release systems,
preferably oral sustained release systems. In one embodiment, a
pump may be used (Langer, supra; Sefton, 1987, CRC Crit Ref Biomed
Eng. 14:201; Saudek et al., 1989, N. Engl. J Med. 321:574).
[0127] In other embodiments, polymeric materials can be used (see
"Medical Applications of Controlled Release," Langer and Wise
(eds.), CRC Pres., Boca Raton, Fla. (1974); "Controlled Drug
Bioavailability," Drug Product Design and Performance, Smolen and
Ball (eds.), Wiley, New York (1984); Langer et al., 1983, J
Macromol. Sci. Rev. Macromol Chem. 23:61; Levy et al., 1985,
Science 228: 190; During et al., 1989, Ann. Neurol. 25.351; Howard
et al., 1989, J. Neurosurg. 71:105).
[0128] In still other embodiments, polymeric materials are used for
oral sustained release delivery. Polymers include, but are not
limited to, sodium carboxymethylcellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose and hydroxyethylcellulose. Other
cellulose ethers have been described (Alderman, Int. J. Pharm.
Tech. & Prod. Mfr. 1984, 5(3) 1-9). Factors affecting drug
release are well known to the skilled artisan and have been
described in the art (Bamba et al., Int. J. Pharm. 1979, 2,
307).
[0129] In still other embodiments, enteric-coated preparations can
be used for oral sustained release administration. Preferred
coating materials include polymers with a pH-dependent solubility
(i.e., pH-controlled release), polymers with a slow or pH-dependent
rate of swelling, dissolution or erosion (i.e., time-controlled
release), polymers that are degraded by enzymes (i.e.,
enzyme-controlled release) and polymers that form firm layers that
are destroyed by an increase in pressure (i.e., pressure-controlled
release).
[0130] In still other embodiments, osmotic delivery systems are
used for oral sustained release administration (Verma et al., Drug
Dev. Ind. Pharm. 2000, 26:695-708). In a preferred embodiment,
OROS.TM. osmotic devices are used for oral sustained release
delivery devices (Theeuwes et al., U.S. Pat. No. 3,845,770;
Theeuwes et al., U.S. Pat. No. 3,916,899).
[0131] For administration by inhalation, a compound may be
conveniently delivered to the lung by a number of different
devices. For example, a Metered Dose Inhaler ("MDI") which utilizes
canisters that contain a suitable low boiling propellant, e.g.,
dichlorodifluoromethane, trichlorofluoromethane,
dichlorotetrafluoroethane, carbon dioxide or other suitable gas may
be used to deliver compounds directly to the lung.
[0132] Alternatively, a Dry Powder Inhaler ("DPI)" device may be
used to administer a compound to the lung (See, e.g., Raleigh et
al., Proc. Amer. Assoc. Cancer Research Annual Meeting 1999, 40,
397). DPI devices typically use a mechanism such as a burst of gas
to create a cloud of dry powder inside a container, which may then
be inhaled by the patient and are well known in the art and may be
purchased from a number of commercial sources. A popular variation
is the multiple dose DPI ("MDDPI") system, which allows for the
delivery of more than one therapeutic dose. For example, capsules
and cartridges of gelatin for use in an inhaler or insufflator may
be formulated containing a powder mix of a compound and a suitable
powder base such as lactose or starch for these systems.
[0133] Another type of device that may be used to deliver a
compound to the lung is a liquid spray device supplied, for
example, by Aradigm Corporation, Hayward, Calif. Liquid spray
systems use extremely small nozzle holes to aerosolize liquid drug
formulations that may then be directly inhaled into the lung.
[0134] In one embodiment, a nebulizer device is used to deliver a
compound to the lung. Nebulizers create aerosols from liquid drug
formulations by using, for example, ultrasonic energy to form fine
particles that may be readily inhaled (e.g., Verschoyle et al.,
British J. Cancer 1999, 80, Suppl. 2, 96; Armer et al., U.S. Pat.
No. 5,954,047; van der Linden et al., U.S. Pat. No. 5,950,619; van
der Linden et al., U.S. Pat. No. 5,970,974).
[0135] In another embodiment, an electrohydrodynamic ("EHD")
aerosol device is used to deliver a compound to the lung. EHD
aerosol devices use electrical energy to aerosolize liquid drug
solutions or suspensions (see e.g., Noakes et al., U.S. Pat. No.
4,765,539; Coffee, U.S. Pat. No. 4,962,885; Coffee, International
Publication No., WO 94/12285; Coffee, International Publication
No., WO 94/14543; Coffee, International Publication No., WO
95/26234, Coffee, International Publication No., WO 95/26235,
Coffee, International Publication No., WO 95/32807). The
electrochemical properties of a compound may be important
parameters to optimize when delivering the compound to the lung
with an EHD aerosol device, and such optimization is routinely
performed by one of skill in the art. EHD aerosol devices may more
efficiently deliver drugs to the lung than existing pulmonary
delivery technologies. Other methods of intra-pulmonary delivery of
a compound will be known to the skilled artisan.
[0136] The compounds of Formulae (I)-(III) and/or compositions
containing such compounds preferably provide therapeutic or
prophylactic levels of propofol upon in vivo administration to a
patient. While not wishing to bound by theory, the promoiety or
promoieties of the compounds may be cleaved either chemically
and/or enzymatically. One or more enzymes present in the stomach,
intestinal lumen, intestinal tissue, blood, liver, brain or any
other suitable tissue of a mammal may enzymatically cleave the
promoiety or promoieties of the administered compounds.
[0137] While not wishing to bound by theory, the promoiety or
promoieties of the compounds may be cleaved prior to absorption by
the gastrointestinal tract (e.g., within the stomach or intestinal
lumen) and/or after absorption by the gastrointestinal tract (e.g.,
in intestinal tissue, blood, liver or other suitable tissue of a
mammal). Preferably, propofol remains conjugated to a promoiety
during transit across the intestinal mucosal barrier to provide
protection from presystemic metabolism. In some embodiments, the
compounds are essentially not metabolized to propofol within
enterocytes, but are metabolized to the parent drug within the
systemic circulation. Cleavage of the promoiety or promoieties of
the compounds after absorption by the gastrointestinal tract may
allow these prodrugs to be absorbed into the systemic circulation
either by active transport, passive diffusion or by a mixture of
both active and passive processes. In one embodiment, the compounds
are actively absorbed through interaction with the intestinal
peptide transporter PEPT1.
[0138] Cleavage of the promoiety or promoieties of the compounds of
Formulae (I)-(III) after absorption by the gastrointestinal tract,
may allow these prodrugs to be absorbed into the systemic
circulation from the large intestine. In some embodiments, the
compounds and/or pharmaceutical compositions containing compounds
of Formulae (I)-(III) are preferably administered as sustained
release systems. In other embodiments, the compounds and/or
pharmaceutical compositions are delivered by oral sustained release
administration. Preferably, in these embodiments, the compounds
and/or pharmaceutical compositions are administered twice per day
(more preferably, once per day).
4.5 Pharmaceutical Compositions
[0139] The present pharmaceutical compositions contain a
therapeutically effective amount of one or more compounds of
Formulae (I)-(III), preferably, in purified form, together with a
suitable amount of a pharmaceutically acceptable vehicle, so as to
provide the form for proper administration to a patient. When
administered intravenously to a patient, the compounds and
pharmaceutically acceptable vehicles are preferably sterile. Water
is a preferred vehicle when a compound is administered
intravenously. Saline solutions and aqueous dextrose and glycerol
solutions can also be employed as liquid vehicles, particularly for
injectable solutions. Suitable pharmaceutical vehicles also include
excipients such as starch, glucose, lactose, sucrose, gelatin,
malt, rice, flour, chalk, silica gel, sodium stearate, glycerol
monostearate, talc, sodium chloride, dried skim milk, glycerol,
propylene, glycol, water, ethanol and the like. The present
compositions, if desired, can also contain minor amounts of wetting
or emulsifying agents, or pH buffering agents. In addition,
auxiliary, stabilizing, thickening, lubricating and coloring agents
may be used.
[0140] Pharmaceutical compositions comprising a compound of
Formulae (I)-(III) may be manufactured by means of conventional
mixing, dissolving, granulating, dragee-making, levigating,
emulsifying, encapsulating, entrapping or lyophilizing processes.
Pharmaceutical compositions may be formulated in conventional
manner using one or more physiologically acceptable carriers,
diluents, excipients or auxiliaries, which facilitate processing of
compounds into preparations which can be used pharmaceutically.
Proper formulation is dependent upon the route of administration
chosen.
[0141] The present pharmaceutical compositions can take the form of
solutions, suspensions, emulsion, tablets, pills, pellets,
capsules, capsules containing liquids, powders, sustained-release
formulations, suppositories, emulsions, aerosols, sprays,
suspensions, or any other form suitable for use. In one embodiment,
the pharmaceutically acceptable vehicle is a capsule (see e.g.,
Grosswald et al., U.S. Pat. No. 5,698,155). Other examples of
suitable pharmaceutical vehicles have been described in the art
(see Remington's Pharmaceutical Sciences, Philadelphia College of
Pharmacy and Science, 19th Edition, 1995). Preferred pharmaceutical
compositions are formulated for oral delivery.
[0142] Pharmaceutical compositions for oral delivery may be in the
form of tablets, lozenges, aqueous or oily suspensions, granules,
powders, emulsions, capsules, syrups, or elixirs, for example.
Orally administered pharmaceutical compositions may contain one or
more optional agents, for example, sweetening agents such as
fructose, aspartame or saccharin, flavoring agents such as
peppermint, oil of wintergreen, or cherry coloring agents and
preserving agents, to provide a pharmaceutically palatable
preparation. Moreover, where in tablet or pill form, the
pharmaceutical compositions may be coated to delay disintegration
and absorption in the gastrointestinal tract, thereby providing a
sustained action over an extended period of time. Selectively
permeable membranes surrounding an osmotically active driving
compound are also suitable for orally administered compounds and
pharmaceutical compositions. In these later platforms, fluid from
the environment surrounding the capsule is imbibed by the driving
compound, which swells to displace the agent or agent composition
through an aperture. These delivery platforms can provide an
essentially zero order delivery profile as opposed to the spiked
profiles of immediate release formulations. A time delay material
such as glycerol monostearate or glycerol stearate may also be
used. Oral pharmaceutical compositions can include standard
vehicles such as mannitol, lactose, starch, magnesium stearate,
sodium saccharine, cellulose, magnesium carbonate, etc. Such
vehicles are preferably of pharmaceutical grade.
[0143] For oral liquid preparations such as, for example,
suspensions, elixirs and solutions, suitable carriers, excipients
or diluents include water, saline, alkyleneglycols (e.g., propylene
glycol), polyalkylene glycols (e.g., polyethylene glycol) oils,
alcohols, slightly acidic buffers between pH 4 and pH 6 (e.g.,
acetate, citrate, ascorbate at between about 5 mM to about 50 mM),
etc. Additionally, flavoring agents, preservatives, coloring
agents, bile salts, acylcarnitines and the like may be added.
[0144] A compound of Formulae (I)-(III) may also be formulated in
rectal or vaginal pharmaceutical compositions such as suppositories
or retention enemas, e.g., containing conventional suppository
bases such as cocoa butter or other glycerides.
[0145] In addition to the formulations described previously, a
compound of Formulae (I)-(III) may also be formulated as a depot
preparation. Such long acting formulations may be administered by
implantation (for example subcutaneously or intramuscularly) or by
intramuscular injection. Thus, for example, a compound may be
formulated with suitable polymeric or hydrophobic materials (for
example as an emulsion in an acceptable oil) or ion exchange
resins, or as sparingly soluble derivatives, for example, as a
sparingly soluble salt.
[0146] When a compound of Formulae (I)-(III) is acidic, it may be
included in any of the above-described formulations as the free
acid, a pharmaceutically acceptable salt, a solvate, hydrate or
N-oxide. Pharmaceutically acceptable salts substantially retain the
activity of the free acid, may be prepared by reaction with bases
and tend to be more soluble in aqueous and other protic solvents
than the corresponding free acid form.
[0147] Liquid drug formulations suitable for use with nebulizers
and liquid spray devices and EHD aerosol devices will typically
include a compound with a pharmaceutically acceptable carrier.
Preferably, the pharmaceutically acceptable carrier is a liquid
such as alcohol, water, polyethylene glycol or a perfluorocarbon.
Optionally, another material may be added to alter the aerosol
properties of the solution or suspension of the compounds.
Preferably, this material is liquid such as an alcohol, glycol,
polyglycol or a fatty acid. Other methods of formulating liquid
drug solutions or suspension suitable for use in aerosol devices
are known to those of skill in the art (e.g., Biesalski, U.S. Pat.
No. 5,112,598; Biesalski, U.S. Pat. No. 5,556,611).
4.6 Combination Therapy
[0148] In certain embodiments, the compounds of Formulae (I)-(III)
can be used in combination therapy with at least one other
therapeutic agent. The compound and the other therapeutic agent(s)
can act additively or, more preferably, synergistically. In a
preferred embodiment, a composition comprising a propofol prodrug
compound is administered concurrently with the administration of
another therapeutic agent, such as for example, another sedative,
hypnotic agent or anesthetic agent (e.g., propofol), which can be
part of the same composition as the propofol prodrug compound or a
different composition. For example, in the treatment of
post-chemotherapy or post-operative nausea and vomiting compounds
of Formulae (I)-(III) may be administered together with 5-HT.sub.3
antagonists (e.g., ondansetron, granisetron, dolasetron,
palonosetron), corticosteroids (e.g., dexamethasone), dopamine
antagonists (e.g., metoclopramide, droperidol, chlorpromazine) or
other antiemetic agents (e.g., benzodiazepines such as diazepam or
lorazepam; NK-1 antagonists such as aprepitant). In other
embodiments, a composition comprising a propofol prodrug compound
is administered prior or subsequent to administration of another
therapeutic agent, such as, for example, another sedative, hypnotic
agent or anesthetic agent, (e.g., propofol).
5. EXAMPLES
[0149] The invention is further defined by reference to the
following examples, which describe preparation of compounds of
Formulae (I)-(III), compositions containing such compounds and
assays for using such compounds and compositions. It will be
apparent to those skilled in the art that many modifications, both
to materials and methods, may be practiced without departing from
the scope of the invention.
[0150] In the examples below, the following abbreviations have the
following meanings. If an abbreviation is not defined, it has its
generally accepted meaning. [0151] Aib=.alpha.-aminoisobutyric acid
[0152] Atm=atmosphere [0153] Boc=tert-butyloxycarbonyl [0154]
Bzl=benzyl [0155] Cbz=carbobenzyloxy [0156]
Dap=L-2,3-diaminopropionic acid [0157] DCC=dicyclohexylcarbodiimide
[0158] DMAP=4-N,N-dimethylaminopyridine [0159] DMEM=Dulbecco's
minimum eagle medium [0160] DMF=N,N-dimethylformamide [0161]
DMSO=dimethylsulfoxide [0162] Fmoc=9-fluorenylmethyloxycarbonyl
[0163] g=gram [0164] h=hour [0165] HBSS=Hank's buffered saline
solution [0166] L=liter [0167] LC/MS=liquid chromatography/mass
spectroscopy [0168] M=molar [0169] min minute [0170] mL=milliliter
[0171] mmol=millimoles [0172] NHS=N-hydroxysuccinimide [0173]
PBS=phosphate buffered saline [0174] THF=tetrahydrofuran [0175]
TFA=trifluoroacetic acid [0176] TMS=trimethylsilyl [0177]
.mu.L=microliter [0178] .mu.M=micromolar [0179] v/v=volume to
volume
Example 1
H-Gly-Thr(.gamma.-OC(O)OPropofol)-OH (10)
STEP A: 2,6-Bis(isopropyl)phenoxycarbonyl chloride (2)
[0180] 20% Phosgene in toluene (139 mL, 0.269 mol) was added to a
stirring solution of propofol (40 g, 0.225 mmol) in toluene (80.0
mL) under a nitrogen atmosphere at 0.degree. C. N,N-dimethylaniline
(34.0 mL, 0.269 mmol) was added dropwise over 15 minutes. The
reaction mixture was allowed to warm to room temperature slowly and
stirred for 14 h. The reaction mixture was filtered through Celite
and the solvent was removed in vacuo. The crude product was carried
to next step without further purification. .sup.1H-NMR (400 MHz,
CDCl.sub.3): .delta. 7.29-7.25 (m, 1H), 7.19-7.17 (m, 2H),
3.04-3.01 (m, 2H), 1.25 (d, J=7.2 Hz, 12H).
STEP B: Boc-Thr(.gamma.-OC(O)OPropofol)-OBn (11)
[0181] To an ice cold solution of L-Boc-Thr-OBn (14.1 g, 0.045 mol)
in dichloromethane (115 mL) was added propofol chloroformate (2)
(14.3 g, 0.059 mmol). To the stirring reaction mixture,
diisopropylethylamine (8.74 mL, 0.050 mmol) was added dropwise over
15 minutes followed by a catalytic amount of dimethylaminopyridine
(0.558 g, 0.005 mol). The resulting mixture was allowed to warm to
room temperature and stirred for 12 h. The mixture was then diluted
with ethyl acetate (150 mL) and washed with 10% aqueous citric acid
solution (2.times.75 mL), brine (2.times.75 mL), dried over
MgSO.sub.4, filtered and concentrated in vacuo. The crude oil was
purified by chromatography on silica gel (eluting with a gradient
of 100% hexane to 20% ethyl acetate in hexane) yielding the product
(11) as a white solid (8.25 g, 36% yield). .sup.1H-NMR (400 MHz,
CD.sub.3OD): .delta. 7.29-7.37 (m, 5H), 7.13-7.22 (m, 3H), 5.36 (m,
1H), 5.11-5.23 (ABq, J=38, 12 Hz, 2H), 4.53 (d, J=3.2 Hz, 1H),
2.98-2.91 (m, 2H), 1.46 (s, 9H), 1.39 (d, J=6.0 Hz, 3H), 1.17 (dd,
J=6.4, 3.2 Hz, 12H). MS (ESI) m/z 536.32 (M+Na).sup.+.
STEP C: H-Thr(.gamma.-OC(O)OPropofol)-OH (12)
[0182] The purified compound (II) from above was dissolved in
dichloromethane (80 mL) and treated with trifluoroacetic acid (20
mL). The resulting mixture was stirred at room temperature for 1 h.
The solvent was removed in vacuo. To the crude residue was added
10% palladium on carbon (800 mg). After degassing with N.sub.2, the
reaction mixture was re-dissolved in a 1:1 (v/v) mixture of ethyl
acetate and methanol (250 mL), degassed once more and a stirred
under an atmosphere of hydrogen (via balloon). The hydrogenolysis
was allowed to proceed over two hours after which the reaction
mixture was filtered through Celite and concentrated in vacuo. A
portion of the compound was purified by reverse phase LC/MS to
afford the title compound (12) as a white solid. .sup.1H-NMR (400
MHz, CD.sub.3OD): .delta. 7.14-7.22 (m, 3H), 5.31-5.37 (m, 1H),
3.72 (d, J=4.4 Hz, 1H), 2.97-3.04 (m, 2H), 1.52 (d, J=6.8 Hz, 3H),
1.18 (dd, J=6.8, 4.8 Hz, 12H). MS (ESI) m/z 324.23 (M+H).sup.+. The
remaining material was used in the next step without further
purification.
STEP D: Boc-Gly-Thr(.gamma.-OC(O)OPropofol)-OH (13)
[0183] To a solution of Boc-glycine (317 mg, 1.8 mmol) in DMF (6
mL) was added diisopropylethylamine (944 .mu.L, 5.4 mmol) followed
by O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
hexafluoro-phosphate (671 mg, 1.76 mmol). The resulting mixture was
stirred at room temperature for 30 minutes, after which was added a
solution of (12) in DMF (2 mL) dropwise and the reaction was
allowed to proceed for two hours. The reaction mixture was then
diluted with ethyl acetate (40 mL) and was washed with 10% aqueous
citric acid solution (2.times.30 mL), saturated aqueous sodium
bicarbonate solution (2.times.30 mL) and brine (2.times.30 mL). The
organic layer was dried over magnesium sulfate, filtered and then
concentrated in vacuo. The crude compound (13) was used without
further purification.
STEP E: H-Gly-Thr(.gamma.-OC(O)OPropofol)-OH (10)
[0184] The crude compound (13) from above was dissolved in
dichloromethane (5 mL) and treated with trifluoroacetic acid (2
mL). The resulting mixture was stirred at room temperature for 1 h.
The solvent was removed in vacuo and the crude residue was purified
by reverse phase LC/MS to afford the title compound (10) (195 mg,
32% yield). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.13-7.20
(m, 3H), 5.43-5.49 (m, 1H), 4.58 (d, J=2.8 Hz, 1H), 3.80 (ABq,
J=27, 16.4 Hz, 2H), 2.94-3.01 (m, 2H), 1.37 (d, J=6.4 Hz, 3H), 1.17
(t, J=6.8 Hz, 12H). MS (ESI) m/z 381.32 (M+H).sup.+.
Example 2
H-Gly-Thr(.gamma.-OC(O)OPropofol)-OH (10)
STEP A: Boc-Gly-Thr-O.TM.Bu (14)
[0185] To a nitrogen purged, ice cold solution of Boc-glycine (2.16
g, 0.012 mol) in acetonitrile was added dicyclohexylcarbodiimide
(2.80 g, 0.013 mol) and N-hydroxy-succinimide (1.49 g, 0.013 mol).
The reaction was allowed to stir for 2 h then was filtered and
concentrated in vacuo. The resulting oil was re-dissolved in a 1:1
(v/v) solution of acetonitrile and water and treated with sodium
bicarbonate (2.23 g, 0.027 mol) and L-threonine .alpha.-t-butyl
ester. The resulting mixture was stirred at room temperature for 14
h and then diluted with ethyl acetate (100 mL). The organic
solution was washed with 10% aqueous citric acid solution
(2.times.50 mL), saturated aqueous sodium bicarbonate solution
(2.times.50 mL) and brine (2.times.50 mL). The organic layer was
dried over magnesium sulfate and then concentrated in vacuo. The
crude compound (14) was used without further purification.
STEP B: Boc-Gly-Thr(.gamma.-OC(O)OPropofol)-O.sup.tBu (15)
[0186] To a stirring ice cold solution of propofol chloroformate
(2) (5.94 g, 0.025 mol) and (14) in dichloromethane (20 mL) was
added pyridine (2 mL, 0.025 mol) dropwise over 10 minutes. The
resulting mixture was allowed to warm to room temperature and
stirred for 12 h. The mixture was diluted with ethyl acetate (75
mL) and washed with 10% aqueous citric acid solution (2.times.30
mL), dried over MgSO.sub.4, filtered and concentrated in vacuo. The
crude product (15) was used in the next step without
purification.
STEP C: H-Gly-Thr(.gamma.-OC(O)OPropofol)-OH (10)
[0187] The crude compound (15) from above was dissolved in
dichloromethane (25 mL) and treated with trifluoroacetic acid (25
mL). The resulting mixture was stirred at room temperature for 3 h.
The solvent was removed in vacuo and the crude residue was purified
by reverse phase LC/MS to afford the title compound (10) (2.67 g,
57% over three steps).
Example 3
H-Ala-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (16)
[0188] Following procedures for the preparation of compound (10)
and substituting Boc-L-alanine for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (16). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.47-5.52 (m, 1H), 4.87 (m, 1H), 4.07-4.12 (q, J=14.4 Hz,
1H), 2.91-2.98 (m, 2H), 1.57 (d, J=7.2 Hz, 3H), 1.40 (d, J=6.4 Hz,
3H), 1.17 (dd, J=6.8, 1.6 Hz, 12H). MS (ESI) m/z 395.91
(M+H).sup.+.
Example 4
H-Asn-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (17)
[0189] Following procedures for the preparation of compound (10)
and substituting Boc-L-asparagine(trityl) for Boc-glycine (in STEP
D of Example 1 or in STEP A of Example 2), adding 1 equivalent of
1N hydrochloric acid in water, and lyophilizing provided the title
compound (17). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.47-5.52 (m, 1H), 4.88 (m, 1H), 4.36 (dd, J=10, 3.6 Hz,
1H), 2.91-2.98 (m, 2H), 2.62-2.81 (m, 2H), 1.41 (d, J=6.4 Hz, 3H),
1.17 (dd, J=6.8, 1.6 Hz, 12H). MS (ESI) m/z 438.81 (M+H).sup.+.
Example 5
H-Lys-Thr(.gamma.-OC(O)OPropofol)-OH Bis-Hydrochloride (18)
[0190] Following procedures for the preparation of compound (10)
and substituting Boc-L-lysine(Boc) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 2 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (18). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.23
(m, 3H), 5.48-5.53 (m, 1H), 4.91 (d, J=2.4 Hz, 1H), 4.10 (t, J=6.4
Hz, 1H), 2.91-2.98 (m, 4H), 1.95-2.02 (m, 2H), 1.71-1.78 (m, 2H),
1.55-1.64 (m, 2H), 1.42 (d, J=6.4 Hz, 3H), 1.17 (d, J=6.8 Hz, 12H).
MS (ESI) m/z 452.32 (M+H).sup.+.
Example 6
H-Ser-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (19)
[0191] Following procedures for the preparation of compound (10)
and substituting Boc-L-serine(O.sup.tBu) for Boc-glycine (in STEP D
of Example 1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (19). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.46-5.51 (m, 1H), 4.87 (m, 1H), 4.11 (dd, J=6.8, 4 Hz,
1H), 4.03 (dd, J=11.6, 4.4 Hz, 1H), 3.87 (dd, J=12, 7.2 Hz, 1H),
2.91-2.98 (m, 2H), 1.41 (d, J=6.4 Hz, 3H), 1.18 (d, J=7.2 Hz, 12H).
MS (ESI) m/z 411.81 (M+H).sup.+.
Example 7
H-Val-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (20)
[0192] Following procedures for the preparation of compound (10)
and substituting Boc-L-Valine for Boc-glycine (in STEP D of Example
1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (20). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.47-5.53 (m, 1H), 4.87 (m, 1H), 3.89 (d, J=5.6 Hz, 1H),
2.91-2.98 (m, 2H), 2.26-2.33 (m, 1H), 1.41 (d, J=6.4 Hz, 3H), 1.17
(dd, J=6.8, 1.6 Hz, 12H), 1.08-1.15 (dd, J=20.4, 7.2 Hz, 6H). MS
(ESI) m/z 423.86 (M+H).sup.+.
Example 8
H-Abu-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (21)
[0193] Following procedures for the preparation of compound (1) and
substituting Boc-aminobutyric acid for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (21). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.43-5.48 (m, 1H), 4.87 (m, 1H), 2.91-3.03 (m, 4H), 2.53
(m, 2H), 1.94-2.02 (m, 2H), 1.38 (d, J=6.4 Hz, 3H), 1.17 (dd,
J=6.8, 3.2 Hz, 12H). MS (ESI) m/z 409.23 (M+H).sup.+.
Example 9
H-.beta.-Ala-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (22)
[0194] Following procedures for the preparation of compound (1) and
substituting Boc-.beta.-alanine for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (22). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.43-5.48 (m, 1H), 4.87 (m, 1H), 3.22 (m, 3H), 2.92-2.99
(m, 2H), 2.77-2.82 (m, 2H), 1.38 (d, J=6.0 Hz, 3H), 1.18 (dd,
J=7.2, 2.8 Hz, 12H). MS (ESI) m/z 395.18 (M+H).sup.+.
Example 10
H-Arg-Thr(.gamma.-OC(O)OPropofol)-OH Tris-Hydrochloride (23)
[0195] Following procedures for the preparation of compound (1) and
substituting Boc-L-arginine(Boc).sub.2 for Boc-glycine (in STEP D
of Example 1 or in STEP A of Example 2), adding 3 equivalents of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (23). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.15-7.23
(m, 3H), 5.49-5.54 (m, 1H), 4.91 (d, J=2.8 Hz, 1H), 4.12 (t, J=6.0
Hz, 1H), 3.26 (t, J=7.2 Hz, 2H), 2.91-2.98 (m, 2H), 1.98-2.04 (m,
2H), 1.75-1.88 (m, 2H), 1.42 (d, J=6.0 Hz, 3H), 1.18 (d, J=7.2 Hz,
12H). MS (ESI) m/z 480.31 (M+H).sup.+.
Example 11
H-Dap-Thr(.gamma.-OC(O)OPropofol)-OH Bis-Hydrochloride (24)
[0196] Following procedures for the preparation of compound (1) and
substituting Boc-L-diaminopropionic(Boc) acid for Boc-glycine (in
STEP D of Example 1 or in STEP A of Example 2), adding 2 equivalent
of 1N hydrochloric acid in water, and lyophilizing provided the
title compound (24). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta.
7.15-7.23 (m, 3H), 5.52-5.57 (m, 1H), 4.98 (d, J=2.4 Hz, 1H), 4.48
(t, J=5.2 Hz, 1H), 3.54 (m, 2H), 2.90-2.97 (m, 2H), 1.46 (d, J=6.4
Hz, 3H), 1.18 (dd, J=7.2, 1.6 Hz 12H). MS (ESI) m/z 410.29
(M+H).sup.+.
Example 12
H-His-Thr(.gamma.-OC(O)OPropofol)-OH Bis-Hydrochloride (25)
[0197] Following procedures for the preparation of compound (1) and
substituting Boc-L-histidine(N-Bn) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), and an additional step (in
STEP E of Example 1 or in STEP C of Example 2) of hydrogenolysis
prior to treatment with trifluoroacetic acid afforded the title
compound (25). To the crude residue (untreated with trifluoroacetic
acid) was added 10% palladium on carbon. After degassing with
N.sub.2, the reaction mixture was re-dissolved in a 1:1 (v/v)
mixture of ethyl acetate and methanol, degassed once more and a
stirred under an atmosphere of hydrogen (via balloon). The
hydrogenolysis was allowed to proceed over two hours after which
the reaction mixture was filtered through Celite and concentrated
in vacuo. After treatment with trifluoroacetic acid, purification
(as described in STEP E of Example 1 or in STEP C of Example 2),
addition of 2 equivalents of 1N hydrochloric acid in water, and
lyophilization, the title compound (25) was afforded. .sup.1H-NMR
(400 MHz, CD.sub.3OD): .delta. 8.87 (s, 1H), 7.55 (s, 1H),
7.14-7.22 (m, 3H), 5.48-5.53 (m, 1H), 4.93 (d, J=2.4 Hz, 1H), 4.43
(t, J=6.4 Hz, 1H), 3.45 (m, 2H), 2.90-2.97 (m, 2H), 1.43 (d, J=6.0
Hz, 3H), 1.17 (dd, J=6.8, 2.8 Hz, 12H). MS (ESI) m/z 461.31
(M+H).sup.+.
Example 13
H-Leu-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (26)
[0198] Following procedures for the preparation of compound (1) and
substituting Boc-L-leucine for Boc-glycine (in STEP D of Example 1
or in STEP A of Example 2), adding 1 equivalent of 1N hydrochloric
acid in water, and lyophilizing provided the title compound (26).
.sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22 (m, 3H),
5.47-5.53 (m, 1H), 4.87 (m, 1H), 4.09 (dd, J=8.8, 4.8 Hz, 1H),
2.92-2.99 (m, 2H), 1.70-1.86 (m, 3H), 1.42 (d, J=6.8 Hz, 3H), 1.17
(d, J=7.2 Hz, 12H), 1.03 (t, J=6 Hz, 6H). MS (ESI) m/z 437.38
(M+H).sup.+.
Example 14
H-Met-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (27)
[0199] Following procedures for the preparation of compound (1) and
substituting Boc-L-methionine for Boc-glycine (in STEP D of Example
1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (27). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.48-5.54 (m, 1H), 4.87 (d, J=2.4 Hz, 1H), 4.15 (t, J=5.6
Hz, 1H), 2.92-2.99 (m, 2H), 2.62-2.74 (m, 2H), 2.18-2.24 (m, 2H),
2.15 (s, 3H), 1.42 (d, J=6.8 Hz, 3H), 1.18 (d, J=7.2 Hz, 12H). MS
(ESI) m/z 455.28 (M+H).sup.+.
Example 15
H-Orn-Thr(.gamma.-OC(O)OPropofol)-OH Bis-Hydrochloride (28)
[0200] Following procedures for the preparation of compound (1) and
substituting Boc-L-ornithine(Boc) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 2 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (28). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.15-7.23
(m, 3H), 5.49-5.54 (m, 1H), 4.92 (d, J=2.0 Hz, 1H), 4.15 (t, J=6.0
Hz, 1H), 2.76-3.03 (m, 4H), 1.99-2.05 (m, 2H), 1.80-1.95 (m, 2H),
1.43 (d, J=6.4 Hz, 3H), 1.18 (d, J=6.8 Hz, 12H). MS (ESI) m/z
438.34 (M+H).sup.+.
Example 16
H-Pro-Thr(.gamma.-OC(O)OPropofol)-OH Hydrochloride (29)
[0201] Following procedures for the preparation of compound (1) and
substituting Boc-L-proline for Boc-glycine (in STEP D of Example 1
or in STEP A of Example 2), adding 1 equivalent of 1N hydrochloric
acid in water, and lyophilizing provided the title compound (29).
.sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.15-7.23 (m, 3H),
5.47-5.53 (m, 1H), 4.86 (d, J=2.4 Hz, 1H), 4.43 (t, J=6.4 Hz, 1H),
3.31-3.48 (m, 2H), 2.90-2.98 (m, 2H), 2.47-2.54 (m, 1H), 2.16-2.23
(m, 1H), 2.02-2.10 (m, 2H), 1.43 (d, J=6.4 Hz, 3H), 1.18 (d, J=6.8
Hz, 12H). MS (ESI) m/z 421.33 (M+H).sup.+.
Example 17
H-D-Asn-Thr(.gamma.-OC(O)OPropofol)-OH (30)
[0202] Following procedures for the preparation of compound (1) and
substituting Boc-D-asparagine(trityl) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2) provided the title compound
(30). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.12-7.20 (m, 3H),
5.47-5.52 (m, 1H), 4.52 (d, J=2.8 Hz, 1H), 4.31 (dd, J=8, 4.8 Hz,
1H), 2.89-3.01 (m, 3H), 2.73-2.79 (m, 1H), 1.34 (d, J=6.0 Hz, 3H),
1.17 (t, J=7.2 Hz, 12H). MS (ESI) m/z 438.33 (M+H).sup.+.
Example 18
H-D-Lys-Thr(.gamma.-OC(O)OPropofol)-OH Bis-Hydrochloride (31)
[0203] Following procedures for the preparation of compound (1) and
substituting Boc-D-lysine(Boc) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 2 equivalent of 2N
hydrochloric acid in water, and lyophilizing provided the title
compound (31). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.15-7.23
(m, 3H), 5.48-5.53 (m, 1H), 4.88 (m, 1H), 4.11 (t, J=6.4 Hz, 1H),
2.92-2.99 (m, 4H), 1.90-2.06 (m, 2H), 1.71-1.79 (m, 2H), 1.52-1.60
(m, 2H), 1.39 (d, J=6.0 Hz, 3H), 1.18 (dd, J=6.8, 3.6 Hz, 12H). MS
(ESI) m/z 452.41 (M+H).sup.+.
Example 19
H-D-Ser-Thr(.gamma.-OC(O)OPropofol-OH Hydrochloride (32)
[0204] Following procedures for the preparation of compound (1) and
substituting Boc-D-serine(O.sup.tBu) for Boc-glycine (in STEP D of
Example 1 or in STEP A of Example 2), adding 1 equivalent of 1N
hydrochloric acid in water, and lyophilizing provided the title
compound (32). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.14-7.22
(m, 3H), 5.46-5.50 (m, 1H), 4.92 (m, 1H), 4.12 (dd, J=9.2, 5.6 Hz,
1H), 3.99-4.06 (m, 1H), 3.85-3.93 (m, 1H), 2.90-2.99 (m, 2H),
1.37-1.42 (dd, J=12, 7.2 Hz, 3H), 1.18 (m, 12H). MS (ESI) m/z
411.35 (M+H).sup.+.
Example 20
H-Asn-D-Thr(.gamma.-OC(O)OPropofol)-OH (33)
[0205] Following procedures for the preparation of compound (1) and
first substituting Boc-D-threonine-OBn for Boc-L-threonine-OBn in
STEP B of Example 1 or D-threonine .alpha.-t-butyl ester in STEP A
of Example 2 and then substituting Boc-asparagine(trityl) for
Boc-glycine (in STEP D of Example 1 or in STEP A of Example 2)
provided the title compound (33). .sup.1H-NMR (400 MHz,
CD.sub.3OD): .delta. 7.12-7.25 (m, 3H), 5.47-5.51 (m, 1H), 4.90 (m,
1H), 4.31 (dd, J=9.2, 4.8 Hz, 1H), 2.82-3.01 (m, 4H), 1.38 (d,
J=6.4 Hz, 3H), 1.18 (dd, J=6.8, 3.2 Hz, 12H). MS (ESI) m/z 438.33
(M+H).sup.+.
Example 21
H-Leu-D-Thr(.gamma.-OC(O)OPropofol)-OH (34)
[0206] Following procedures for the preparation of compound (1) and
first substituting Boc-D-threonine-OBn for Boc-L-threonine-OBn in
STEP B of Example 1 or D-threonine .alpha.-t-butyl ester in STEP A
of Example 2 and then substituting Boc-leucine for Boc-glycine (in
STEP D of Example 1 or in STEP A of Example 2) provided the title
compound (34). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.13-7.21
(m, 3H), 5.48-5.51 (m, 1H), 4.60 (d, J=2.4 Hz, 1H), 4.06 (t, J=7.6
Hz, 1H), 2.95-3.02 (m, 2H), 1.64-1.84 (m, 3H), 1.18 (d, J=6.0 Hz,
12H), 1.02-1.07 (dd, J=12.4, 6.4 Hz, 6H). MS (ESI) m/z 437.38
(M+H).sup.+.
Example 22
H-Ser-D-Thr(.gamma.-OC(O)OPropofol)-OH (35)
[0207] Following procedures for the preparation of compound (1) and
first substituting Boc-D-threonine-OBn for Boc-L-threonine-OBn in
STEP B of Example 1 or D-threonine .alpha.-t-butyl ester in STEP A
of Example 2 and then substituting Boc-leucine for Boc-glycine (in
STEP D of Example 1 or in STEP A of Example 2) provided the title
compound (35). .sup.1H-NMR (400 MHz, CD.sub.3OD): .delta. 7.13-7.21
(m, 3H), 5.42-5.48 (m, 1H), 4.60 (d, J=2.8 Hz, 1H), 4.10 (dd,
J=7.2, 4.8 Hz, 1H), 3.98 (dd, J=11.2, 4.4 Hz, 1H), 3.86 (dd,
J=11.2, 6.8 Hz, 1H), 2.94-3.02 (m, 2H), 1.41 (d, J=6.8 Hz, 3H),
1.18 (d, J=6.8 Hz, 12H). MS (ESI) m/z 411.38 (M+H).sup.+.
Example 23
In Vitro Compound Transport Assays
Analysis of Electrogenic Transport in PEPT1-Expressing Xenopus
Oocytes
[0208] Transport-induced currents were also measured in Xenopus
oocytes transfected with rat and human PEPT1 as described in PCT
Application WO01/20331. Briefly:
[0209] RNA preparation: Rat and human PEPT1 transporter cDNAs were
subcloned into a modified pGEM plasmid that contains 5' and 3'
untranslated sequences from the Xenopus .beta.-actin gene. These
sequences increase RNA stability and protein expression. Plasmid
cDNA was linearized and used as template for in vitro transcription
(Epicentre Technologies transcription kit, 4:1
methylated:non-methylated GTP).
[0210] Xenopus oocyte isolation. Xenopus laevis frogs were
anesthetized by immersion in Tricaine (1.5 g/mL in deionized water)
for 15 min. Oocytes were removed and digested in frog ringer
solution (90 mM NaCl, 2 mM KCl, 1 mM MgCl.sub.2, 10 mM NaHEPES, pH
7.45, no CaCl.sub.2) with 1 mg/mL collagenase (Worthington Type 3)
for 80-100 min with shaking. The oocytes were washed 6 times, and
the buffer changed to frog ringer solution containing CaCl.sub.2
(1.8 mM). Remaining follicle cells were removed if necessary. Cells
were incubated at 16.degree. C., and each oocyte injected with
10-20 .mu.g RNA in 45 .mu.L solution.
[0211] Electrophysiology measurements. Transport currents were
measured 2-14 days after injection, using a standard two-electrode
electrophysiology set-up (Geneclamp 500 amplifier, Digidata
1320/PCLAMP software and ADInstruments hardware and software were
used for signal acquisition). Electrodes (2-4 m.OMEGA.) were
microfabricated using a Sutter Instrument puller and filled with 3M
KCl. The bath was directly grounded (transporter currents were less
than 0.3 .mu.A). Bath flow was controlled by an automated perfusion
system (ALA Scientific Instruments, solenoid valves).
[0212] For transporter pharmacology, oocytes were clamped at -60 to
-90 mV, and continuous current measurements acquired using PowerLab
Software and an ADInstruments digitizer. Current signals were
lowpass filtered at 20 Hz and acquired at 4-8 Hz. All bath and
drug-containing solutions were frog ringers solution containing
CaCl.sub.2. Drugs were applied for 10-30 seconds until the induced
current reached a new steady-state level, followed by a control
solution until baseline currents returned to levels that preceded
drug application. The difference current (baseline subtracted from
peak current during drug application) reflected the net movement of
charge resulting from electrogenic transport and was directly
proportional to transport rate. Recordings were made from a single
oocyte for up to 60 min, enabling 30-40 separate compounds to be
tested per oocyte. Compound-induced currents were saturable and
gave half-maximal values at substrate concentrations comparable to
radiolabel competition experiments. To compare results between
oocytes expressing different levels of transport activity, a
saturating concentration of glycyl-sarcosine (1 mM) was used as a
common reference to normalize results from test compounds. Using
this normalization procedure I.sub.max (i.e. maximal induced
current) for different compounds tested on different oocytes could
be compared.
[0213] Each of the compounds (10), (16)-(20), (24)-(28) and (32)
elicited PEPT-specific currents significantly above background (at
least 2% of I.sub.max for Gly-Sar) when tested at 3 mM on oocytes
expressing PEPT1, confirming that these compounds serve as
substrates for this transporter.
Example 24
Standard Methods for Determination of Enzymatic Cleavage of
Prodrugs in Vitro
[0214] The stability of propofol prodrugs were evaluated in one or
more in vitro systems using a variety of tissue preparations
following methods known in the art. Tissues were obtained from
commercial sources (e.g., Pel-Freez Biologicals, Rogers, Ark., or
GenTest Corporation, Woburn, Mass.). Experimental conditions used
for the in vitro studies are described in Table 1 below. Each
preparation was incubated with test compound at 37.degree. C. for
one hour. Aliquots (50 .mu.L) were removed at 0, 30, and 60 min and
quenched with 0.1% trifluoroacetic acid in acetonitrile. Samples
were then centrifuged and analyzed by LC/MS/MS (see Example 134
below for method details). Stability of drug conjugates towards
specific enzymes (e.g., peptidases, etc.) were also assessed in
vitro by incubation with the purified enzyme.
[0215] Pancreatin Stability: Stability studies were conducted by
incubating conjugate (5 .mu.M) with 1% (w/v) pancreatin (Sigma,
P-1625, from porcine pancreas) in 0.025 M Tris buffer containing
0.5 M NaCl (pH 7.5) at 37.degree. C. for 60 min. The reaction was
stopped by addition of 2 volumes of methanol. After centrifugation
at 14,000 rpm for 10 min, the supernatant was removed and analyzed
by LC/MS/MS.
[0216] Caco-2 Homogenate S9 Stability: Caco-2 cells were grown for
21 days prior to harvesting. Culture medium was removed and cell
monolayers were rinsed and scraped off into ice-cold 10 mM sodium
phosphate/0.15 M potassium chloride, pH 7.4. Cells were lysed by
sonication at 4.degree. C. using a probe sonicator. Lysed cells
were then transferred into 1.5 mL centrifuge vials and centrifuged
at 9000 g for 20 min at 4.degree. C. The resulting supernatant
(Caco-2 cell homogenate S9 fraction) was aliquoted into 0.5 mL
vials and stored at -80.degree. C. until used.
[0217] For stability studies, prodrug (5 .mu.M) was incubated in
Caco-2 homogenate S9 fraction (0.5 mg protein per mL) for 60 min at
37.degree. C. Concentrations of intact prodrug and released
propofol were determined at zero time and 60 minutes using
LC/MS/MS.
[0218] Preferred conjugates demonstrate at least 1% cleavage to
produce the free drug or an active metabolite thereof within a 60
minute period, as summarized in Table 2.
TABLE-US-00001 TABLE 1 Standard Conditions for Conjugate In Vitro
Metabolism Studies Substrate Preparation Concentration Cofactors
Human Plasma 2.0 .mu.M None Human Liver S9 2.0 .mu.M NADPH (0.5
mg/mL) Caco-2 5.0 .mu.M None Homogenate Pancreatin 5.0 .mu.M None
*NADPH generating system, e.g., 1.3 mM NADP+, 3.3 mM
glucose-6-phosphate, 0.4 U/mL glucose-6-phosphate dehydrogenase,
3.3 mM magnesium chloride and 0.95 mg/mL potassium phosphate, pH
7.4.
TABLE-US-00002 TABLE 2 % of Propofol Released from Propofol
Prodrugs after 60 min. in Various Tissue Preparations (10) (16)
(18) (23) (24) (25) (26) Human Plasma 2 4 12 25 0 0 0 Human Liver
S9 2 22 32 93 1 8 37 (0.5 mg/mL) Caco-2 S9 30 33 33 100 21 52 93
Pancreatin 43 25 1 4 0 0 30 (27) (28) Human Plasma 0 2 Human Liver
S9 0 11 (0.5 mg/mL) Caco-2 S9 20 54 Pancreatin 0 0
Example 25
Uptake of Propofol Following Oral Administration of Prodrugs to
Monkeys
Step A
Administration Protocol
[0219] Test compounds were administered by oral gavage or as an
intravenous bolus injection to groups of two to four adult male
Cynomologous (Macaca fascicularis) monkeys (weight approx 5 kg) as
solutions in water or PEG400 at a dose of 25 mg-equivalents of
propofol per kg body weight. Animals were fasted overnight before
the study and for 4 hours post-dosing. Blood samples (1.0 mL) were
obtained via the femoral vein at intervals over 24 hours after oral
dosing. Blood was quenched immediately using acetonitrile with 1%
formic acid and then was frozen at -80.degree. C. until analyzed.
Test compounds are administered in the monkeys with a minimum of 72
hour wash out period between dosing sessions.
Step B
LC/MS/MS Analysis
[0220] Concentrations of propofol in plasma were determined using
an API 4000 LC/MS/MS instrument equipped with an Agilent 1100
binary pump and an Agilent autosampler. The column was a Phenomenex
Hydro-RP 4.6*50 mm column operating at room temperature. The mobile
phases were 2 mM aqueous ammonium acetate (A) and 95% acetonitrile
with 5 mM ammonium acetate (B). The gradient condition was: 5% B
for 1 min, increasing to 90% B in 2.5 min and maintained for 2 min.
20 .mu.L of sample was injected. A Turbo-IonSpray source was used,
and propofol was detected in negative ion mode in Q1 at m/z=177.
Prodrugs were detected in positive ion mode, using MRM transitions
of 323.97/101.91 for (12), 452.11/84.05 for (18), 411.04/189.05 for
(19), 480.05/70.24 for (23), 409.99/159.00 for (24), as well as
prodrugs (10) and (27). The peaks were integrated using Analyst 1.2
quantitation software.
[0221] Oral bioavailability (F) of the prodrugs as propofol in
monkeys were determined by comparison of the areas under the
propofol concentration versus time curves (AUC) following oral
administration of the prodrugs with the AUC measured following
intravenous administration of propofol itself on a dose-normalized
basis. Each of the above compounds (prodrugs (10), (12), (18),
(19), (23), (24), and (27)) had oral bioavailabilities as propofol
>10%, illustrating that actively transported prodrugs can afford
significant enhancements in oral bioavailability of propofol.
Example 26
Uptake of Propofol Following Oral or Intravenous Administration of
Prodrugs to Rats
Step 1
Administration Protocol
[0222] Propofol or propofol prodrug was administered as an
intravenous bolus injection or by oral gavage to groups of four to
six adult male Sprague-Dawley rats (weight approx 250 g). Animals
were conscious at the time of the experiment. Propofol or propofol
prodrug was orally administered as an aqueous solution at a dose
equivalent to 25 mg of propofol per kg body weight. When
administered intravenously, propofol or propofol prodrug was
administered as a solution in Diprivan.RTM. (Astra-Zeneca) at a
dose equivalent to 15 mg of propofol per kg body weight. Animals
were fasted overnight before the study and for 4 hours post-dosing.
Blood samples (0.3 mL) were obtained via a jugular vein cannula at
intervals over 8 hours after oral dosing. Blood was quenched
immediately using acetonitrile with 1% formic acid and then was
frozen at -80.degree. C. until analyzed.
Step 2
Sample Preparation for Absorbed Drug
[0223] 1. In blank 1.5 mL tubes, 300 .mu.L of 0.1% formic acid in
acetonitrile was added.
[0224] 2. Rat blood (300 .mu.L) was collected at different times
into EDTA tubes and vortexed to mix. A fixed volume of blood (100
.mu.L) was immediately added into the Eppendorf tube and vortexed
to mix.
[0225] 3. Ten microliters of a propofol standard stock solution
(0.04, 0.2, 1, 5, 25, 100 .mu.g/mL) was added to 90 .mu.L of blank
rat blood quenched with 300 .mu.L of 0.1% formic acid in
acetonitrile. Then, 20 .mu.L of p-chlorophenylalanine was added to
each tube to make the to make up a final calibration standard
(0.004, 0.02, 0.1, 0.5, 2.5, 10 .mu.g/mL).
[0226] 4. Samples were vortexed and centrifuged at 14,000 rpm for
10 min.
[0227] 5. Supernatant was analyzed by LC/MS/MS.
Step 3
LC/MS/MS Analysis
[0228] An API 4000 LC/MS/MS spectrometer equipped with Agilent 1100
binary pumps and a CTC HTS-PAL autosampler were used in the
analysis. A Phenomenex Synergihydro-RP 4.6.times.30 mm column was
used during the analysis. The mobile phase for propofol analysis
was (A) 2 mM ammonium acetate, and (B) 5 mM ammonium acetate in 95%
acetonitrile. The mobile phase for the analysis of propofol
prodrugs was (A) 0.1% formic acid, and (B) 0.1% formic acid in
acetonitrile. The gradient condition was: 10% B for 0.5 min, then
to 95% B in 2.5 min, then maintained at 95% B for 1.5 min. The
mobile phase was returned to 10% B for 2 min. An ACPI source was
used on the API 4000. The analysis was done in negative ion mode
for propofol and positive ion mode for propofol prodrugs. The MRM
transition for each analyte was optimized using standard solutions.
5 .mu.L of the samples were injected. Non-compartmental analysis
was performed using WinNonlin (v.3.1 Professional Version,
Pharsight Corporation, Mountain View, Calif.) on individual animal
profiles. Summary statistics on major parameter estimates was
performed for C.sub.max (peak observed concentration following
dosing), T.sub.max (time to maximum concentration is the time at
which the peak concentration was observed), AUC.sub.(0-t) (area
under the serum concentration-time curve from time zero to last
collection time, estimated using the log-linear trapezoidal
method), AUC.sub.(0-.infin.), (area under the serum concentration
time curve from time zero to infinity, estimated using the
log-linear trapezoidal method to the last collection time with
extrapolation to infinity), and t.sub.1/2,z (terminal
half-life).
[0229] The oral bioavailability (F) of propofol was determined by
comparing the area under the propofol concentration vs time curve
(AUC) following oral administration of propofol with the AUC of the
propofol concentration vs time curve following intravenous
administration of propofol on a dose normalized basis. Using this
measurement technique, the oral bioavailability of propofol was
found to be very low, as expected (F=0.23%).
[0230] Oral bioavailability (F) of propofol, resulting from oral
administration of the propofol prodrugs (10) and (27) in rats was
determined by comparing the area under the propofol concentration
vs time curve (AUC) following oral administration of the propofol
prodrugs (10) and (27), and with the AUC measured following
intravenous administration of an equimolar dose of propofol itself.
Prodrugs (10) and (27) provided greater than 10% absolute oral
bioavailability of propofol, i.e., compared to the bioavailability
of propofol following intravenous administration of an equimolar
dose of propofol itself. Thus, prodrugs (10) and (27) provided at
least about 40 times higher oral bioavailability of propofol
compared to the oral bioavailability of propofol itself. The result
illustrates that prodrugs of the present disclosure can afford
significant enhancements in oral bioavailability of propofol in
rats.
[0231] Finally, it should be noted that there are alternative ways
of implementing the present invention. Accordingly, the present
embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein, but may be modified within the scope and equivalents
of the claim(s) issuing herefrom. All publications and patents
cited herein are incorporated by reference.
* * * * *