U.S. patent application number 12/487911 was filed with the patent office on 2009-10-08 for small molecule compositions for sexual dysfunction.
This patent application is currently assigned to Palatin Technologies, Inc.. Invention is credited to Shubh D. Sharma.
Application Number | 20090253713 12/487911 |
Document ID | / |
Family ID | 40765895 |
Filed Date | 2009-10-08 |
United States Patent
Application |
20090253713 |
Kind Code |
A1 |
Sharma; Shubh D. |
October 8, 2009 |
Small Molecule Compositions for Sexual Dysfunction
Abstract
Compounds of the general formula: ##STR00001## or a
pharmaceutically acceptable salt thereof, wherein R.sub.1, R.sub.2,
R.sub.3, and X are as defined. Further provided are methods for
treatment of sexual dysfunction, including erectile dysfunction and
female sexual dysfunction, and combination drugs and method of use
thereof, including a compound of the invention and one or more
second sexual dysfunction pharmaceutical agents.
Inventors: |
Sharma; Shubh D.; (Cranbury,
NJ) |
Correspondence
Address: |
PALATIN TECHNOLOGIES, INC.
4-C CEDAR BROOK DRIVE, CEDAR BROOK CORPORATE CENTER
CRANBURY
NJ
08512
US
|
Assignee: |
Palatin Technologies, Inc.
Cranbury
NJ
|
Family ID: |
40765895 |
Appl. No.: |
12/487911 |
Filed: |
June 19, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11036281 |
Jan 14, 2005 |
7550602 |
|
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12487911 |
|
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60536690 |
Jan 14, 2004 |
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Current U.S.
Class: |
514/254.09 ;
514/255.01; 514/260.1; 514/387; 544/278; 544/373; 544/384; 544/391;
548/302.7 |
Current CPC
Class: |
C07D 487/04
20130101 |
Class at
Publication: |
514/254.09 ;
548/302.7; 544/373; 544/391; 544/384; 544/278; 514/387; 514/255.01;
514/260.1 |
International
Class: |
A61K 31/496 20060101
A61K031/496; C07D 487/04 20060101 C07D487/04; C07D 403/06 20060101
C07D403/06; C07D 241/04 20060101 C07D241/04; C07D 495/04 20060101
C07D495/04; A61K 31/4188 20060101 A61K031/4188; A61K 31/495
20060101 A61K031/495; A61K 31/519 20060101 A61K031/519 |
Claims
1. A compound of the general formula II or III: ##STR00027##
wherein: R.sub.1 is a bond or a linker unit with from one to six
atoms joined one to the other by bonds and forming a chain selected
from the group consisting of carbon (C), oxygen (O) and nitrogen
(N) and a ring group including at least one substituted or
unsubstituted aromatic ring, including carbocyclic or heterocyclic
aromatic rings, bicylic ring groups, and bridged ring groups
wherein at least one ring is an aromatic ring, and fused ring
groups other than 6,6-membered fused ring structures wherein at
least one ring is an aromatic ring; R.sub.2 is hydrogen (H) or a
C.sub.1 to C.sub.6 aliphatic linear or branched chain; R.sub.3 is a
natural or unnatural L- or D-amino acid with a carbocyclic aromatic
group-containing side chain, a natural or unnatural L- or D-amino
acid with a carbocyclic aromatic group-containing side chain and an
amine capping group, or is -R.sub.6-R.sub.7; R.sub.6 is a D-isomer
of Phe, Phe(4-F), Phe(4-Br), Phe(4-CF.sub.3), Phe(4-Cl), Phe(3-Cl),
Phe(2-Cl), Phe(2,4-diCl), Phe(2,4-diF), Phe(3,4-diCl), Phe(5-Cl),
Phe(2-C.sub.1-4-Me), Phe(2-Me,4-Cl), Phe(2-F,4-Cl), Phe(4-I),
Phe(2,4-diMe), Phe(2-Cl,4-CF.sub.3), Phe(3,4-diF), Phe(4-I),
Phe(3,4-di-OMe), Phe(4-Me), Phe(4-OMe), Phe(4-NC), or
Phe(4-NO.sub.2); R.sub.7 is -R.sub.8, -R.sub.9 or -R.sub.8-R.sub.9;
R.sub.8 is between one and three natural or unnatural L- or D-amino
acids; R.sub.9 is an amine capping group; X is (CH.sub.2).sub.n,
NH, O, C.dbd.O, C.dbd.S, S, S.dbd.O or SO.sub.2; and n is 0, 1, 2
or 3.
2. The compound of claim 1, wherein R.sub.1 is: ##STR00028## where
z is from 1 to 5.
3. The compound of claim 2, wherein at least one aromatic ring of
R.sub.1 has one or more halogen, alkyl or aryl substituents.
4. The compound of claim 1, wherein R.sub.2 is --CH.sub.3,
--(CH.sub.2).sub.yCH.sub.3, where y is from 1 to 5, or is
##STR00029##
5. The compound of claim 1 wherein R.sub.3 is a D-amino acid.
6. The compound of claim 4 wherein R.sub.3 is a D-isomer of Phe,
Phe(4-F), Phe(4-Br), Phe(4-CF.sub.3), Phe(4-Cl), Phe(3-Cl),
Phe(2-Cl), Phe(2,4-diCl), Phe(2,4-diF), Phe(3,4-diCl), Phe(5-Cl),
Phe(2-C.sub.1-4-Me), Phe(2-Me,4-Cl), Phe(2-F,4-Cl), Phe(4-I),
Phe(2,4-diMe), Phe(2-Cl,4-CF.sub.3), Phe(3,4-diF), Phe(4-I),
Phe(3,4-di-OMe), Phe(4-Me), Phe(4-OMe), Phe(4-NC), or
Phe(4-NO.sub.2).
7. The compound of claim 1 wherein R.sub.3 is -R.sub.6-R.sub.7,
where R.sub.6 is a D-isomer of Phe, Phe(4-F), Phe(4-Br),
Phe(4-CF.sub.3), Phe(4-Cl), Phe(3-Cl), Phe(2-Cl), Phe(2,4-diCl),
Phe(2,4-diF), Phe(3,4-diCl), Phe(5-Cl), Phe(2-C.sub.1-4-Me),
Phe(2-Me,4-Cl), Phe(2-F,4-Cl), Phe(4-I), Phe(2,4-diMe),
Phe(2-Cl,4-CF.sub.3), Phe(3,4-diF), Phe(4-I), Phe(3,4-di-OMe),
Phe(4-Me), Phe(4-OMe), Phe(4-NC), or Phe(4-NO.sub.2), and R.sub.7
is --R.sub.8, -R.sub.9 or -R.sub.8-R.sub.9, where R.sub.8 is
between one and about three natural or unnatural L- or D-amino acid
residues and R.sub.9 is an amine capping group.
8. The compound of claim 1 wherein the amine capping group is
selected from the group consisting of methyl, dimethyl, ethyl,
propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, allyl,
cyclopropane methyl, hexanoyl, heptanoyl, acetyl, propionoyl,
butanoyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl,
cinnamoyl, phenyl, benzyl, benzoyl, 12-Ado, 7'-amino heptanoyl,
6-Ahx, Amc and 8-Aoc.
9. The compound of claim 1, wherein the carbocyclic aromatic group
of the carbocyclic aromatic group-containing side chain of R.sub.3
is: ##STR00030##
10. The compound of claim 1, wherein the carbocyclic aromatic group
of the carbocyclic aromatic group-containing side chain of R.sub.3
is: ##STR00031## with one or more halogen, alkyl or aryl
substituents.
11. A pharmaceutical composition, comprising the compound of claim
1 and a pharmaceutically acceptable carrier.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a division of U.S. patent application Ser. No.
11,036,281, filed on Jan. 1, 2005, and now U.S. Pat. No. 7,550,602,
issued on Jun. 23, 2009, which in turn claims the benefit of the
filing of U.S. Provisional Patent Application Ser. No. 60/536,690,
entitled "Small Molecule Compositions for Sexual Dysfunction",
filed on Jan. 14, 2004, and the specification thereof of each is
incorporated herein by reference.
[0002] The subject of this application is related to U.S. patent
application Ser. No. 11/031,898, entitled "Peptide Compositions for
Treatment of Sexual Dysfunction", filed on Jan. 7, 2005, and to
U.S. patent application Ser. No. 11/036,273, entitled
"Metallopeptide Compositions for Treatment of Sexual Dysfunction",
filed concurrently herewith, and the specification thereof of each
is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention (Technical Field)
[0004] The present invention relates to small ring-core molecules
characterized in that they may be employed for the treatment of
sexual dysfunction in mammals, including both male erectile
dysfunction and female sexual dysfunction in humans, without
modulating feeding behavior in mammals and without being
substantially specific for any melanocortin receptor, including not
substantially inhibiting binding at MC4-R, and methods for the
treatment of sexual dysfunction in mammals without modulation of
feeding behavior or eliciting or causing other responses
characteristic of MC4-R specific molecules.
[0005] 2. Description of Related Art
[0006] Note that the following discussion refers to a number of
publications by author(s) and year of publication, and that due to
recent publication dates certain publications are not to be
considered as prior art vis-a-vis the present invention. Discussion
of such publications herein is given for more complete background
and is not to be construed as an admission that such publications
are prior art for patentability determination purposes.
[0007] A family of melanocortin receptor types and subtypes have
been identified, including melanocortin-1 receptors (MC1-R)
expressed on normal human melanocytes and melanoma cells,
melanocortin-2 receptors (MC2-R) for ACTH (adrenocorticotropin)
expressed in cells of the adrenal gland, melanocortin-3 and
melanocortin-4 receptors (MC3-R and MC4-R) expressed primarily in
cells in the hypothalamus, mid-brain and brainstem, and
melanocortin-5 receptors (MC5-R), expressed in a wide distribution
of tissues.
[0008] Compounds specific for MC3-R or MC4-R, and particularly
MC4-R, are believed to be useful in regulation of energy
homeostasis, including use as agents for attenuating food intake
and body weight gain, for use in treatment of anorexia, as a weight
gain aid, for treatment of obesity, and other treatment of food
intake and metabolism-related disorders and conditions. Compounds
specific for MC3-R and/or MC4-R, and particularly MC4-R, affect
sexual response, and can be used as agents for treatment of sexual
dysfunction, including male erectile dysfunction.
[0009] Most scientific investigators ascribe the sexual activity of
melanotropin ligands to MC4-R. For example, see Van der Ploeg L H,
Martin W J, Howard A D, Nargund R P, Austin C P, Guan X, Drisko J,
Cashen D, Sebhat I, Patchett A A, Figueroa D J, DiLella A G,
Connolly B M, Weinberg D H, Tan C P, Palyha O C, Pong S S, MacNeil
T, Rosenblum C, Vongs A, Tang R, Yu H, Sailer A W, Fong T M, Huang
C, Tota M R, Chang R S, Stearns R, Tamvakopoulos C, Christ G,
Drazen D L, Spar B D, Nelson R J, MacIntyre D E. A role for the
melanocortin 4 receptor in sexual function. Proc Natl Acad Sci USA
99:11381-6 (2002). Evidence in favor of this hypothesis comes from
the fact that a sexual response elicited by an MC4-R agonist can be
blocked by an MC4-R antagonist. However, a few reports also suggest
that MC4-R receptors may not be involved in eliciting sexual
function response (Vergoni A V, Bertolini A, Guidetti G,
Karefilakis V, Filaferro M, Wikberg J E, Schioth H B. Chronic
melanocortin 4 receptor blockage causes obesity without influencing
sexual behavior in male rats. J Endocrino, 166:419-26 (2000)).
[0010] Because of the myriad biological effects of compounds
specific for melanocortin receptors, there is a need for compounds
and methods, including methods of selection of compounds, to
differentiate the effects. More specifically, there is a need for
compounds that effect a sexual response, by the same or similar
regulatory pathways as those implicated in MC4-R-specific
compounds, without eliciting other biological effects related to
MC4-R, including without limitation energy homeostasis or feeding
behaviors. For most pharmaceutical applications it is desirably to
have a compound that is specific for a single biological effect,
such as for example a compound that regulates and elicits a sexual
response, and that is not substantially specific for MC4-R, is not
an agonist or antagonist with respect to MC4-R, and that does not
regulate energy homeostasis, such as by decreasing food intake
and/or body weight or elicit or cause other responses
characteristic of MC4-R specific molecules.
BRIEF SUMMARY OF THE INVENTION
[0011] Small molecules are provided based on a ring core structure,
and including as pendent groups at least an aromatic or substituted
aromatic group, preferably phenyl or substituted phenyl group,
including but not limited to a Phe or substituted Phe side chain
moiety, one or more C.sub.1 to C.sub.6 aliphatic linear or branched
groups, wherein at least one C.sub.1 to C.sub.6 aliphatic linear or
branched group does not contain a cationic center, and an aromatic
ring moiety, but specifically excluding 6,6 bicyclic rings in which
one or both rings thereof are aromatic, such as specifically
excluding naphthalene, which small molecules induce a sexual
response without substantially binding melanocortin receptors, and
may be employed for treatment of sexual dysfunction, but which do
not activate MC4-R and thus are not agonists or partial agonists at
MC4-R, and further do not affect energy homeostasis, such as
altering food intake and/or body weight, and do not elicit or cause
other responses characteristic of MC4-R specific molecules.
[0012] The invention thus provides a method for regulating or
modulating sexual response, including penile erection in males,
without regulating or modulating energy homeostasis, including
feeding behavior, by administration of a therapeutically effective
amount of a compound of this invention.
[0013] In one embodiment, the invention provides a compound of the
general formula I:
##STR00002##
wherein:
[0014] L is a conformationally restricted ring system consisting of
a single ring or bicyclic non-aromatic carbocyclic ring system, a
single ring or bicyclic aromatic carbocyclic ring system, a single
ring or bicyclic non-aromatic heterocyclic ring system or a single
ring or bicyclic aromatic heterocyclic ring system, with the single
ring comprising from 5 to about 9 atoms, and the bicyclic ring
system comprising from 5 to about 9 atoms in each ring, where the
dashed line represents the common bond between shared atoms of the
two rings when L is a bicyclic ring system;
[0015] R.sub.1 is a bond or a linker unit comprising from one to
six backbone atoms selected from the group consisting of carbon
(C), oxygen (O) and nitrogen (N) and a ring group including at
least one substituted or unsubstituted aromatic ring, including
carbocyclic or heterocyclic aromatic rings, fused ring groups,
bicylic ring groups, and bridged ring groups wherein at least one
ring is an aromatic ring, but excluding 6,6-membered fused ring
structures wherein at least one ring is an aromatic ring;
[0016] R.sub.2 is hydrogen (H) or a C.sub.1 to C.sub.6 aliphatic
linear or branched chain;
[0017] R.sub.3 comprises a bond or a linker unit and at least one
carbocyclic aromatic ring; and
[0018] R.sub.4 and R.sub.5 independently are H or a C.sub.1 to
C.sub.6 aliphatic linear or branched chain.
[0019] In compounds of formula I, or formula X as hereafter
described, R.sub.1 can be:
##STR00003##
where z is from 1 to 5. The at least one aromatic ring of R.sub.1,
including those set forth above, can be functionalized with one or
more halogen, alkyl or aryl groups.
[0020] In compounds of formula I, R.sub.2 can be --CH.sub.3, or
--(CH.sub.2).sub.yCH.sub.3, where y is from 1 to 5, or can be
##STR00004##
[0021] In compounds of formula I, or formula X as hereafter
described, R.sub.3 can include a natural or unnatural L- or D-amino
acid with an aromatic group-containing side chain wherein the L
ring system atom to which R.sub.3 is bound is N. In a preferred
embodiment R.sub.3 includes a D-amino acid. R.sub.3 can also
further include an amine capping group. Thus in one embodiment
R.sub.3 is a D-isomer of Phe, Phe(4-F), Phe(4-Br), Phe(4-CF.sub.3),
Phe(4-Cl), Phe(3-Cl), Phe(2-Cl), Phe(2,4-diCl), Phe(2,4-diF),
Phe(3,4-diCl), Phe(5-Cl), Phe(2-C.sub.1-4-Me), Phe(2-Me, 4-Cl),
Phe(2-F, 4-Cl), Phe(4-I), Phe(2,4-diMe), Phe(2-Cl,4-CF.sub.3),
Phe(3,4-diF), Phe(4-I), Phe(3,4-di-OMe), Phe(4-Me), Phe(4-OMe),
Phe(4-NC), or Phe(4-NO.sub.2). In another embodiment, R.sub.3 is
-R.sub.6-R.sub.7, where R.sub.6 is a D-isomer of Phe, Phe(4-F),
Phe(4-Br), Phe(4-CF.sub.3), Phe(4-Cl), Phe(3-Cl), Phe(2-Cl),
Phe(2,4-diCl), Phe(2,4-diF), Phe(3,4-diCl), Phe(5-Cl),
Phe(2-C.sub.1-4-Me), Phe(2-Me, 4-Cl), Phe(2-F, 4-Cl), Phe(4-I),
Phe(2,4-diMe), Phe(2-Cl,4-CF.sub.3), Phe(3,4-diF), Phe(4-I),
Phe(3,4-di-OMe), Phe(4-Me), Phe(4-OMe), Phe(4-NC), or
Phe(4-NO.sub.2), and R.sub.7 is -R.sub.8, -R.sub.9 or
-R.sub.8-R.sub.9, where R.sub.8 is between one and about three
natural or unnatural L- or D-amino acid residues and R.sub.9 is an
amine capping group. R.sub.9, the amine capping group, can be
methyl, dimethyl, ethyl, propyl, isopropyl, butyl, isobutyl,
pentyl, hexyl, allyl, cyclopropane methyl, hexanoyl, heptanoyl,
acetyl, propionoyl, butanoyl, phenylacetyl, cyclohexylacetyl,
naphthylacetyl, cinnamoyl, phenyl, benzyl, benzoyl, 12-Ado, 7-amino
heptanoyl, 6-Ahx, Amc or 8-Aoc.
[0022] In compounds of formula I, or formula X as hereafter
described, the at least one carbocyclic aromatic ring of R.sub.3
can include any of the following:
##STR00005##
In the foregoing rings, at least one carbocyclic aromatic ring of
R.sub.3 can be functionalized with one or more halogen, alkyl or
aryl groups.
[0023] In compounds of formula I, or formula X as hereafter
described, preferably neither R.sub.4 nor R.sub.5 have a cationic
center. In one embodiment, R.sub.4 and R.sub.5 can each
independently be hydrogen, methyl, ethyl, propyl, butyl, pentyl,
hexyl or a corresponding branched chain isomer.
[0024] In compounds of formula I, or formula X as hereafter
described, the compound can be of any of the following formulas
##STR00006##
or wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as
defined, X is in each instance (CH.sub.2).sub.n, CH, NH, N, O,
C.dbd.O, C.dbd.S, S, S.dbd.O or SO.sub.2 and n is, 1, 2 or 3.
[0025] In another embodiment, the invention provides a compound of
the general formula X:
##STR00007##
wherein:
[0026] L is a conformationally restricted ring system consisting of
a single ring or bicyclic non-aromatic carbocyclic ring system, a
single ring or bicyclic aromatic carbocyclic ring system, a single
ring or bicyclic non-aromatic heterocyclic ring system or a single
ring or bicyclic aromatic heterocyclic ring system, with the single
ring comprising from 5 to about 9 atoms, and the bicyclic ring
system comprising from 5 to about 9 atoms in each ring, where the
dashed line represents the common bond between shared atoms of the
two rings when L is a bicyclic ring system;
[0027] R.sub.1 is a bond or a linker unit comprising from one to
six backbone atoms selected from the group consisting of C, O and N
and a ring group including at least one substituted or
unsubstituted aromatic ring, including carbocyclic or heterocyclic
aromatic rings, fused ring groups, bicylic ring groups, and bridged
ring groups wherein at least one ring is an aromatic ring, but
excluding 6,6-membered fused ring structures wherein at least one
ring is an aromatic ring;
[0028] R.sub.10 is a C.sub.1 to C.sub.6 aliphatic linear or
branched chain with a heteroatom unit without a cationic center,
wherein at least one heteroatom is N;
[0029] R.sub.3 comprises a bond or a linker unit and at least one
carbocyclic aromatic ring; and
[0030] R.sub.4 and R.sub.5 independently are H or a C.sub.1 to
C.sub.6 aliphatic linear or branched chain.
[0031] In the compound of formula X, R.sub.10 can be
--(CH.sub.2).sub.yNHCOCH.sub.3, --(CH.sub.2).sub.yNHCOOCH.sub.3,
--(CH.sub.2).sub.yNHCONH.sub.2, --(CH.sub.2).sub.yNHCOH,
--(CH.sub.2).sub.yNHSO.sub.2NH.sub.2,
--(CH.sub.2).sub.yNHSO.sub.2CH.sub.3, or
--(CH.sub.2).sub.yCONH.sub.2, where y is from 1 to 5.
[0032] Compounds of formula I or formula X can further be
characterized in that the compound does not substantially inhibit
the binding of .alpha.-MSH or an .alpha.-MSH analog to melanocortin
receptors. Preferably the compound is therapeutically effective for
treatment of sexual dysfunction.
[0033] In another embodiment, in the compounds of formula I or X,
R.sub.3 is alternatively one of the following aromatic groups:
##STR00008## ##STR00009##
[0034] The invention further provides a pharmaceutical composition
for treating sexual dysfunction in a mammal, including the compound
of formula I through X as set forth above and a pharmaceutically
acceptable carrier. The pharmaceutical composition can further
include a second sexual dysfunction pharmaceutical agent.
[0035] The invention further provides a method of treating sexual
dysfunction in a mammal, comprising administration of a
therapeutically effective amount of a compound formula I through X
as set forth above or a pharmaceutically acceptable salt thereof.
The method can further include administration of a therapeutically
effective amount of a second sexual dysfunction pharmaceutical
agent, such as an MC4-R agonist or a PDE-5 inhibitor. In one
embodiment of the method, the mammal is male and the sexual
dysfunction is erectile dysfunction. In another embodiment, the
mammal is female and the sexual dysfunction is female sexual
dysfunction.
[0036] In general, a compound of any of the foregoing formulas, but
which differs in that the group corresponding to R.sub.2 has a
cationic center, such as a C.sub.1 to C.sub.6 aliphatic linear or
branched chain with a cationic center, such as for example a side
chain moiety of Arg or Lys, may demonstrate efficacy for treatment
of sexual dysfunction, such as by inducing a penile erection in a
male mammal, but will also activate MC4-R and thus may be an
agonist, partial agonist or antagonist at MC4-R, and thus will
modulate energy homeostasis, such as in the case of an MC4-R
agonist causing a decrease in food intake. Thus compounds where the
group corresponding to R.sub.2 is a C.sub.1 to C.sub.6 aliphatic
linear or branched chain with a cationic center may be
melanocortin-specific ligands, and such compounds may inhibit, or
substantially inhibit, binding of 1251-NDP-.alpha.-MSH at MC3-R
and/or MC4-R. Compounds where the group corresponding to R.sub.2 is
a C.sub.1 to C.sub.6 aliphatic linear or branched chain with a
cationic center may induce a sexual response, but may also affect
energy homeostasis, such as altering food intake and/or body
weight, or elicit or cause other responses characteristic of MC4-R
specific molecules. Based on data relating to these and other
compounds, it is hypothesized that the absence of a cationic center
at the R.sub.2 position renders the compounds of this invention
inactive, or substantially inactive, at melanocortin receptors, and
specifically at MC3-R and/or MC4-R, but nonetheless such compounds
may induce a sexual response, and may thus be employed for
treatment of sexual dysfunction. Because of the inactivity or
substantial inactivity of compounds without a cationic center at
the R.sub.2 position in any of a variety of melanocortin
receptor-specific assays known in the art, it was not heretofore
known that such compounds, notwithstanding such inactivity or
substantial inactivity, elicit a sexual response, and thus may be
employed for treatment of sexual dysfunction. This discovery thus
provides compounds and methods for treatment of sexual dysfunction
without otherwise causing biological or pharmacological effects
associated with compounds specific for one or more melanocortin
receptors, particularly compounds that are agonists or antagonists
at MC3-R and/or MC4-R.
[0037] A primary object of the present invention is to provide a
compound and method for initiating and/or maintaining a sexual
response in a mammal, and for the treatment of sexual dysfunction
in mammals, including both male erectile dysfunction and female
sexual dysfunction in humans, without modulating feeding
behavior.
[0038] Other objects, advantages and novel features, and further
scope of applicability of the present invention will be set forth
in part in the detailed description to follow, and in part will
become apparent to those skilled in the art upon examination of the
following, or may be learned by practice of the invention. The
objects and advantages of the invention may be realized and
attained by means of the instrumentalities and combinations
particularly pointed out in the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Definitions. Before proceeding further with the description
of the invention, certain terms are defined as set forth
herein.
[0040] The "amino acid" and "amino acids" used in this invention,
and the terms as used in the specification and claims, include the
known naturally occurring protein amino acids, which are referred
to by both their common three letter abbreviation and single letter
abbreviation. See generally Synthetic Peptides: A User's Guide, G A
Grant, editor, W.H. Freeman & Co., New York, 1992, the
teachings of which are incorporated herein by reference, including
the text and table set forth at pages 11 through 24. As set forth
above, the term "amino acid" also includes stereoisomers and
modifications of naturally occurring protein amino acids,
non-protein amino acids, post-translationally modified amino acids,
enzymatically synthesized amino acids, derivatized amino acids,
constructs or structures designed to mimic amino acids, and the
like. Modified and unusual amino acids are described generally in
Synthetic Peptides: A User's Guide, cited above; Hruby V J,
Al-obeidi F and Kazmierski W: Biochem J 268:249-262, 1990; and
Toniolo C: Int J Peptide Protein Res 35:287-300, 1990; the
teachings of all of which are incorporated herein by reference.
[0041] The term "amino acid side chain moiety" used in this
invention includes any side chain of any amino acid, as the term
"amino acid" is defined herein, including any derivative of an
amino acid side chain moiety, as the term "derivative" is defined
herein. Therefore, this includes the side chain moiety present in
naturally occurring amino acids. It further includes side chain
moieties in modified naturally occurring amino acids, such as
glycosylated amino acids. It further includes side chain moieties
in stereoisomers and modifications of naturally occurring protein
amino acids, non-protein amino acids, post-translationally modified
amino acids, enzymatically synthesized amino acids, derivatized
amino acids, constructs or structures designed to mimic amino
acids, and the like. For example, the side chain moiety of any
amino acid disclosed herein is included within the definition of an
amino acid side chain moiety.
[0042] The "derivative" of an amino acid side chain moiety includes
any modification to or variation in any amino acid side chain
moieties, including a modification of naturally occurring amino
acid side chain moieties. By way of example, derivatives of amino
acid side chain moieties include straight chain or branched, cyclic
or noncyclic, substituted or unsubstituted, and saturated or
unsaturated alkyl, aryl or aralkyl moieties.
[0043] The following abbreviations for amino acids, amino acid side
chain moieties and derivatives and constituents thereof have the
meanings giving, it being understood that any amino acid may be in
either the L- or D-configuration:
[0044] Abu--gamma-amino butyric acid
[0045] 2-Abz--2-amino benzoic acid
[0046] 3-Abz--3-amino benzoic acid
[0047] 4-Abz--4-amino benzoic acid
[0048] Achc--1-amino-cyclohexane-1-carboxylic acid
[0049] Acpc--1-amino-cyclopropane-1-carboxylic acid
[0050] 12-Ado--12-amino dodecanoic acid
[0051] Aib--alpha-aminoisobutyric acid
[0052] 1-Aic--2-aminoindane-1-carboxylic acid
[0053] 2-Aic--2-aminoindane-2-carboxylic acid
[0054] 6-Ahx--6-amino hexanoic acid
[0055] Beta-Ala--beta-alanine
[0056] Amb--4-(aminomethyl)-benzoic acid
[0057] Amc--4-(aminomethyl)-cyclohexane carboxylic acid
[0058] 7'-amino-heptanoyl--NH.sub.2--(CH.sub.2).sub.6CO--
[0059] 8-Aoc--8-amino octanoic acid
[0060] Arg(Tos)--N.sub.G-para-tosyl-arginine
[0061] Asp(anilino)--beta-anilino-aspartic acid
[0062] Asp(3-C.sub.1-anilino)--beta-(3-chloro-anilino)-aspartic
acid
[0063] Asp(3,5-diCl-anilino)--beta-(3,5-dichloro anilino)-aspartic
acid
[0064] Atc--2-aminotetralin-2-carboxylic acid
[0065] 11-Aun--11-amino undecanoic acid
[0066] AVA--5-amino valeric acid
[0067] Beta-hHyp(Bzl)--beta-(O-benzyl)-homohydroxyproline
[0068] Beta-hSer(Bzl)--beta-(O-benzyl)-homoserine
[0069] Bip--biphenylalanine
[0070] Bzl--benzyl
[0071] Bz--benzoyl
[0072] Cha--cyclohexylalanine
[0073] Chg--cyclohexylglycine
[0074] Cmpi--4-caboxymethyl-piperazine
[0075] Cys(Bzl)--S-benzyl-cysteine
[0076] Dip--3,3-diphenylalanine
[0077] Disc--1,3-dihydro-2H-isoindolecarboxylic acid
[0078]
Dpr(beta-Ala)--N.sup.beta-(3-aminopropionyl)-alpha,beta-diaminoprop-
ionic acid
[0079] Et--ethyl
[0080] GAA--epsilon-guanidino acetic acid
[0081] GBzA--4-guanidino benzoic acid
[0082] B-Gpa--3-guanidino propionic acid
[0083] GVA(Cl)--beta-chloro-epsilon-guanidino valeric acid
[0084] Heptanoyl --CH.sub.3--(CH.sub.2).sub.5CO--
[0085] hPhe--homophenylalanine
[0086] hSer--homoserine
[0087] Hyp--hydroxy praline
[0088] hHyp--homo hydroxy praline
[0089] Hyp(Bzl)--O-benzyl-hydroxyproline
[0090] Hyp(2-naphthly)--O-2' naphthyl-hydroxyproline
[0091] Hyp(Phenyl)--O-phenyl-hydroxyproline
[0092] Idc--indoline-2-carboxylic acid
[0093] Igl--indanylglycine
[0094] Inp--isonipecotic acid
[0095] Lys(Z)--N-epsilon-benzyloxycarbonyl-lysine
[0096] Me--methyl
[0097] Nal 1--3-(1-naphthyl)alanine
[0098] Nal 2--3-(2-naphthyl)alanine
[0099] (N-Bzl)Nal 2--N-benzyl-3-(2-naphthyl) alanine
[0100] 2-Naphthylacetyl--2-naphthyl-CH.sub.2CO--
[0101] (Nlys)Gly--N-(4-aminobutyl)-glycine
[0102] (N-PhEt)Nal 2--N(2-phenylethyl)-3-(2-naphthyl)alanine
[0103] OcHx--cyclohexyl ester
[0104] Phg--phenylglycine
[0105] Phe(4-F)--para-fluoro-phenylalanine
[0106] Phe(4-Br)--4-bromo-phenylalanine
[0107] Phe(4-CF.sub.3)--4-trifluoromethyl-phenylalanine
[0108] Phe(4-Cl)--4-chloro-phenylalanine
[0109] Phe(3-Cl)--3-chloro-phenylalanine
[0110] Phe(2-Cl)--2-chloro-phenylalanine
[0111] Phe(2,4-diCl)--2,4,-dichloro-phenylalanine
[0112] Phe(2,4-diF)--2,4-difluoro-phenylalanine
[0113] Phe(3,4-diCl)--3,4,-dichloro-phenylalanine
[0114] Phe(5-Cl)--5-chloro-phenylalanine
[0115] Phe(2-C.sub.1-4-Me)--2-chloro-4-methyl-phenylalanine
[0116] Phe(2-Me,4-Cl)--4-chloro-2-methyl-phenylalanine
[0117] Phe(2-F,4-Cl)--4-chloro-2-fluoro-phenylalanine
[0118] Phe(2,4-diMe)-2,4-dimethyl-phenylalanine
[0119]
Phe(2-Cl,4-CF.sub.3)--2-chloro-4-trifluoromethyl-phenylalanine
[0120] Phe(3,4-diF)--3,4,-difluoro-phenylalanine
[0121] Phe(4-I)--4-iodo-phenylalanine
[0122] Phe(3,4-di-OMe)--3,4,-dimethoxy-phenylalanine
[0123] Phe(4-Me)--4-methyl-phenylalanine
[0124] Phe(4-OMe)--4-methoxy-phenylalanine
[0125] Phe(4-NC)--4-cyano-phenylalanine
[0126] Phe(4-NO.sub.2)--4-nitro-phenylalanine
[0127] Pip--pipecolic acid
[0128] Pr--propyl
[0129] Pr-i--isopropyl
[0130] 4-phenylPro--4-phenyl-pyrrolidin-2-carboxylic acid
[0131] 5-phenylPro--5-phenyl-pyrrolidin-2-carboxylic acid
[0132] 3-Pya--3-pyridylalanine
[0133] Pyr--pyroglutamic acid
[0134] Qal(2')--beta-(2-quinolyl)-alanine
[0135] Sal--3-styrylalanine
[0136] Sar--sarcosine
[0137] Ser(Bzl)--O-benzyl-serine
[0138] Ser(2-Naphthyl)--O-2-Naphthyl-serine
[0139] Ser(Phenyl)--O-2-Phenyl-serine
[0140] Ser(4-Cl-Phenyl)--O-4-Cl-Phenyl-serine
[0141] Ser(2-Cl-Phenyl)--O-2-Cl-Phenyl-serine
[0142] Ser(p-Cl-Bzl)--O-4-Cl-Benzyl-serine
[0143] Thr(Bzl)--O-Benzyl-threonine
[0144] Thr(2-Naphthyl)--O-(2-naphthyl)-threonine
[0145] Thr(Phenyl)--O-phenyl-threonine
[0146] Thr(4-Cl-Phenyl)--O-(4-Cl-phenyl)-threonine
[0147] Thr(2-Cl-Phenyl)--O-(2-Cl-phenyl)-threonine
[0148] Beta-homoThr(Bzl)--O-Benzyl-bate-homothreonine
[0149] Tic--1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid
[0150] Tiq--1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid
[0151] Tle--tert-butylalanine
[0152] Tpi--1,2,3,4-tetrahydronorharman-3-carboxylic acid
[0153] Tyr(Bzl)--O-benzyl-tyrosine
[0154] Tyr(2,6-DiCl-Bzl)--O-(2,6 dichloro)benzyl-tyrosine
[0155] Conventional amino acid residues have their conventional
meaning as given in Chapter 2400 of the Manual of Patent Examining
Procedure, 8.sup.th Ed. Thus, "Nle" is norleucine, "Asp" is
aspartic acid, "His" is histidine, "D-Phe" is D-phenylalanine,
"Arg" is arginine, "Trp" is tryptophan, "Lys" is lysine, "Gly" is
glycine, "Pro" is praline, "Tyr" is tyrosine, "Ser" is serine and
so on.
[0156] The following amino acids, or side chains thereof, may be
employed, in either the L- or D-configuration as appropriate, in
certain embodiments of this invention:
##STR00010## ##STR00011##
[0157] The term "homolog" includes, without limitation, (a) a
D-amino acid residue or side chain substituted for an L-amino acid
residue side chain, (b) a post-translationally modified residue or
side chain substituted for the residue or side chain, (c) a
non-protein or other modified amino acid residue or side chain
based on another such residue or side chain, such as phenylglycine,
homophenylalanine, ring-substituted halogenated, and alkylated or
arylated phenylalanines for a phenylalanine residue, diamino
propionic acid, diamino butyric acid, ornithine, lysine and
homoarginine for an arginine residue, and the like, and (d) any
amino acid residue or side chain, coded or otherwise, or a
construct or structure that mimics an amino acid residue or side
chain, and which has at least a similarly charged side chain
(neutral, positive or negative), preferably a similar
hydrophobicity or hydrophilicity, and preferably a similar side
chain in terms of being a saturated aliphatic side chain, a
functionalized aliphatic side chain, an aromatic side chain or a
heteroaromatic side chain.
[0158] The term "alkene" includes unsaturated hydrocarbons that
contain one or more double carbon-carbon bonds. Examples of such
alkene groups include ethylene, propene, and the like.
[0159] The term "alkenyl" includes a linear monovalent hydrocarbon
radical of two to six carbon atoms or a branched monovalent
hydrocarbon radical of three to six carbon atoms containing at
least one double bond; examples thereof include ethenyl,
2-propenyl, and the like.
[0160] The "alkyl" groups specified herein include those alkyl
radicals of the designated length in either a straight or branched
configuration. Examples of such alkyl radicals include methyl,
ethyl, propyl, isopropyl, butyl, sec-butyl, tertiary butyl, pentyl,
isopentyl, hexyl, isohexyl, and the like.
[0161] The term "alkynal" includes a linear monovalent hydrocarbon
radical of two to six carbon atoms or a branched monovalent
hydrocarbon radical of three to six carbon atoms containing at
least one triple bond; examples thereof include ethynyl, propynal,
butynyl, and the like.
[0162] The term "aryl" includes a monocyclic or bicyclic aromatic
hydrocarbon radical of 6 to 12 ring atoms, and optionally
substituted independently with one or more substituents selected
from alkyl, haloalkyl, cycloalkyl, alkoxy, alkylthio, halo, nitro,
acyl, cyano, amino, monosubstituted amino, disubstituted amino,
hydroxy, carboxy, or alkoxy-carbonyl. Examples of an aryl group
include phenyl, biphenyl, naphthyl, 1-naphthyl, and 2-naphthyl,
derivatives thereof, and the like.
[0163] The term "aralkyl" includes a radical -R.sup.aR.sup.b where
R.sup.a is an alkylene (a bivalent alkyl) group and R.sup.b is an
aryl group as defined above. Examples of aralkyl groups include
benzyl, phenylethyl, 3-(3-chlorophenyl)-2-methylpentyl, and the
like.
[0164] The term "aliphatic" includes compounds with hydrocarbon
chains, such as for example alkanes, alkenes, alkynes, and
derivatives thereof.
[0165] The term "acyl" includes a group RCO--, where R is an
organic group. An example is the acetyl group CH.sub.3CO--.
[0166] A group or aliphatic moiety is "acylated" when an alkyl or
substituted alkyl group as defined above is bonded through one or
more carbonyl {-(C.dbd.O)-} groups.
[0167] An "omega amino derivative" includes an aliphatic moiety
with a terminal amino group. Examples of omega amino derivatives
include aminoheptanoyl and the amino acid side chain moieties of
ornithine and lysine.
[0168] The term "heteroaryl" includes mono- and bicyclic aromatic
rings containing from 1 to 4 heteroatoms selected from nitrogen,
oxygen and sulfur. 5- or 6-membered heteroaryl are monocyclic
heteroaromatic rings; examples thereof include thiazole, oxazole,
thiophene, furan, pyrrole, imidazole, isoxazole, pyrazole,
triazole, thiadiazole, tetrazole, oxadiazole, pyridine, pyridazine,
pyrimidine, pyrazine, and the like. Bicyclic heteroaromatic rings
include, but are not limited to, benzothiadiazole, indole,
benzothiophene, benzofuran, benzimidazole, benzisoxazole,
benzothiazole, quinoline, benzotriazole, benzoxazole, isoquinoline,
purine, furopyridine and thienopyridine.
[0169] An "amide" includes compounds that have a trivalent nitrogen
attached to a carbonyl group (--CO.NH.sub.2), such as methylamide,
ethylamide, propylamide, and the like.
[0170] An "imide" includes compounds containing an imido group
(--CO.NH.CO--).
[0171] An "amine" includes compounds that contain an amino group
(--NH.sub.2).
[0172] A "nitrile" includes compounds that are carboxylic acid
derivatives and contain a (--CN) group bound to an organic
group.
[0173] An amino acid side chain moiety is "hydrogen bonding" when
the side chain includes hydrogen donors or alternatively hydrogen
acceptors.
[0174] The term "halogen" is intended to include the halogen atoms
fluorine, chlorine, bromine and iodine, and groups including one or
more halogen atoms, such as --CF.sub.3 and the like.
[0175] By a melanocortin receptor "agonist" is meant an endogenous
or drug substance or compound that can interact with a melanocortin
receptor and initiate a pharmacological response characteristic of
the melanocortin receptor. By a melanocortin receptor "antagonist"
is meant an endogenous or drug substance or a compound that opposes
the melanocortin receptor-associated responses normally induced by
a melanocortin receptor agonist agent.
[0176] By "binding affinity" is meant the ability of a compound or
drug to bind to its biological target.
[0177] An "amine capping group" includes any terminal group
attached through a terminal amine, including but not limited to any
omega amino derivative, acyl group or terminal aryl or aralkyl
including groups such as methyl, dimethyl, ethyl, propyl,
isopropyl, butyl, isobutyl, pentyl, hexyl, allyl, cyclopropane
methyl, hexanoyl, heptanoyl, acetyl, propionoyl, butanoyl,
phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, phenyl,
benzyl, benzoyl, 12-Ado, 7-amino heptanoyl, 6-Ahx, Amc or 8-Aoc, as
well as terminal groups such polyethylene glycol (PEG) with an
average or formula molecular weight of between 100 and 10,000,
optionally a PEG carboxylic acid derivative capable of forming a
covalent bond with a terminal amine.
[0178] The term "composition", as in pharmaceutical composition, is
intended to encompass a product comprising the active
ingredient(s), and the inert ingredient(s) that make up the
carrier, as well as any product which results, directly or
indirectly, from combination, complexation or aggregation of any
two or more of the ingredients, or from dissociation of one or more
of the ingredients, or from other types of reactions or
interactions of one or more of the ingredients. Accordingly, the
pharmaceutical compositions of the present invention encompass any
composition made by admixing a compound of the present invention
and one or more pharmaceutically acceptable carriers, and
optionally one or more pharmaceutically active ingredients and
agents.
[0179] A variety of chemicals and compounds are employed in this
invention, and the following abbreviations have the meanings
given:
[0180] AcOH acetic acid
[0181] Boc tertiary butyloxycarbonyl
[0182] Cbz benzyloxycarbonyl
[0183] DCM dichloromethane
[0184] DEAD diethyl azodicarboxylate
[0185] DIAD diisopropyl azodicarboxylate
[0186] DIC 1,3-diisopropylcarbodiimide
[0187] EtOAc ethyl acetate
[0188] Fmoc 9-fluorenylmethoxycarbonyl
[0189] HEPES 4-(2-hydroxyethyl)1-piperazineethanesulfonic acid
[0190] HOAt 1-hydroxy-7-azabenzotriazole
[0191] IBCF isobutyl chloroformate
[0192] LAH lithium aluminum hydride
[0193] NMM N-methyl-morpholine
[0194] Prt A protecting group, such as Boc, Cbz or Fmoc
[0195] TBTU 2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethyluronium
tetrafluoroborate TEA triethylamine
[0196] TFA trifluoroacetic acid
[0197] THF tetrahydrofuran
[0198] TPP triphenylphosphine
[0199] "Sexual dysfunction" means any condition that inhibits or
impairs normal sexual function, including coitus. The term is not
limited to physiological conditions, and includes psychogenic
conditions or perceived impairment without a formal diagnosis of
pathology or disorder. Sexual dysfunction includes erectile
dysfunction in a male mammal and female sexual dysfunction in a
female mammal.
[0200] "Erectile dysfunction" is a disorder involving the failure
of a male mammal to achieve functional erection, ejaculation, or
both. Erectile dysfunction is accordingly synonymous with
impotence, and includes the inability to attain or sustain an
erection of sufficient rigidity for coitus. Symptoms of erectile
dysfunction include an inability to achieve or maintain an
erection, ejaculatory failure, premature ejaculation, or inability
to achieve an orgasm. An increase in erectile dysfunction is often
associated with age or may be caused by a physical disease or as a
side-effect of drug treatment.
[0201] "Female sexual dysfunction" is a disorder including sexual
arousal disorder. The term "sexual arousal disorder" includes a
persistent or recurrent failure to attain or maintain the
lubrication-swelling response of sexual excitement until completion
of sexual activity. Sexual dysfunction in females can also include
inhibited orgasm and dyspareunia, which is painful or difficult
coitus. Female sexual dysfunction includes, but is not limited to,
a number of categories of diseases, conditions and disorders
including hypoactive sexual desire disorder, sexual anhedonia,
sexual arousal disorder, dyspareunia and vaginismus. Hypoactive
sexual desire disorder includes a disorder in which sexual
fantasies and desire for sexual activity are persistently or
recurrently diminished or absent, causing marked distress or
interpersonal difficulties. Hypoactive sexual desire disorder can
be caused by boredom or unhappiness in a long-standing
relationship, depression, dependence on alcohol or psychoactive
drugs, side effects from prescription drugs, or hormonal
deficiencies. Sexual anhedonia includes decreased or absent
pleasure in sexual activity. Sexual anhedonia can be caused by
depression, drugs, or interpersonal factors. Sexual arousal
disorder can be caused by reduced estrogen, illness, or treatment
with diuretics, antihistamines, antidepressants, or
antihypertensive agents. Dyspareunia and vaginismus are sexual pain
disorders characterized by pain resulting from penetration and may
be caused, for example, by medications which reduce lubrication,
endometriosis, pelvic inflammatory disease, inflammatory bowel
disease or urinary tract problems.
[0202] The compounds disclosed herein can be used for both medical
applications and animal husbandry or veterinary applications.
Typically, the product is used in humans, but may also be used in
other mammals. The term "patient" is intended to denote a mammalian
individual, and is so used throughout the specification and in the
claims. The primary applications of this invention involve human
patients, but this invention may be applied to laboratory, farm,
zoo, wildlife, pet, sport or other animals.
[0203] Combination Therapy. It is also possible and contemplated to
use the compounds of this invention in combination with other drugs
or agents. These other drugs and agents may include melanocortin
receptor-specific agents that induce erectile activity, including
specifically MC3-R and MC4-R agonists, phosphodiesterase-5
inhibitors, testosterone, prostaglandin and the like. In a
preferred embodiment of the invention, compounds of the invention
are used in combination with a therapeutically effective amount of
a cyclic-GMP-specific phosphodiesterase inhibitor or an
alpha-adrenergic receptor antagonist. Similarly, the compounds of
this invention may be used in combination with any known mechanical
aids or devices.
[0204] The present invention thus provides methods of treating
sexual dysfunction, the methods comprising the step of
administering to the patient having or at risk of having sexual
dysfunction a therapeutically effective amount of a compound of
this invention in combination with a therapeutically effective
amount of a second sexual dysfunction pharmaceutical agent. The
compound of this invention may be administered simultaneously with,
prior to or subsequent to administration with a therapeutically
effective amount of a second sexual dysfunction pharmaceutical
agent. Preferably the compound of this invention is administered
within one hour, preferably within less than one-half hour, of
administration of a therapeutically effective amount of a second
sexual dysfunction pharmaceutical agent. However, for certain forms
of combination therapy, such as for example in combination with a
therapeutically effective amount of a hormone or hormone-related
sexual dysfunction pharmaceutical agent, the hormone or
hormone-related sexual dysfunction pharmaceutical agent may be
administered on an independent schedule, such that there is no set
or specific temporal relationship between administration of the
compound of this invention and the hormone or hormone-related
sexual dysfunction pharmaceutical agent. Thus, for example, the
hormone or hormone-related sexual dysfunction pharmaceutical agent
may be administered on a daily or other dose, or by means of
patches or other continuous administration schedules, with
administration of the compound of this invention when desired or
needed by the patient.
[0205] The present invention thus provides methods of treating
sexual dysfunction, the methods comprising the step of
administering to a patient having or at risk of having sexual
dysfunction a therapeutically effective amount of a compound of
this invention in combination with a compound that is a
melanocortin receptor agonist.
[0206] The present invention further also provides methods of
treating sexual dysfunction, the methods comprising the step of
administering to a patient having or at risk of having sexual
dysfunction a therapeutically effective amount of a compound of
this invention in combination with a compound that is a
melanocortin receptor agonist and in combination with another
compound that is useful in the treatment of sexual dysfunction.
[0207] In a preferred embodiment of combination therapy the sexual
dysfunction is female sexual dysfunction.
[0208] In an especially preferred embodiment of combination therapy
the sexual dysfunction is erectile dysfunction.
[0209] In a preferred embodiment of the foregoing methods, the
melanocortin receptor agonist is an agonist of MC3-R or MC4-R, and
preferably MC4-R. The agonist may be a non-selective MC3-R and
MC4-R agonist.
[0210] The present invention also provides pharmaceutical
compositions that comprise 1) a compound of this invention and 2) a
compound that is a melanocortin receptor agonist.
[0211] The present invention also provides pharmaceutical
compositions that comprise 1) a compound of this invention; 2) a
compound that is a melanocortin receptor agonist; and 3) a third
compound useful for the treatment of sexual dysfunction.
[0212] The present invention also provides pharmaceutical
compositions that comprise 1) a compound of this invention and 2) a
second compound useful for the treatment of sexual dysfunction.
[0213] Representative agonists of the melanocortin receptor which
are a second compound useful in combination therapy are disclosed
in the following publications, which are incorporated here by
reference in their entirety: M. E. Hadley et al., Discovery and
development of the novel melanogenic drugs, in Integration of
Pharmaceutical Discovery and Development: Case Studies, edited by
Borschart et al., Plenum Press, New York (1998); R. T. Dorr et al.,
Evaluation of Melanotan-II, A Superpotent Cyclic Melanotropic
Peptide in a Pilot Phase-I Clinical Study. Life Sci. 58:1777-1784
(1996); and R. A. H. Adan, Identification of Antagonists for
Melanocortin MC3, MC4, and MC5 Receptors. Eur. J. Pharmacol.,
269:331-337 (1994).
[0214] In one embodiment of the composition above, the agonists are
melanocyte-stimulating hormones (MSH) including .alpha.-, .alpha.-,
and .gamma.-MSH and/or adrenocorticotropic hormones (ACTH).
[0215] In another embodiment of the composition above, the
melanocortin receptor agonist is Melanotan-II (MT-II). A preferred
melanocortin receptor agonist includes any linear or cyclic
melanocortin receptor-specific agonist peptide disclosed in
International Application WO 03/006620 or a metallopeptide
disclosed in International Application WO 02/064091. A particularly
preferred melanocortin receptor agonist is
Ac-Nle-cyclo(-Asp-His-D-Phe-Arg-Trp-Lys)-OH, as disclosed in U.S.
Pat. No. 6,579,968. Alternatively, the agonist may be any agonist
disclosed in any of the following patents or patent applications:
U.S. Pat. No. 6,534,503, 6,472,398, 6,458,790, 6,410,548,
6,376,509, or 6,350,760; U.S. Published Application Nos.
2002/0137664, 2002/0004512, 2002/0143141, or US 2003/0069169; or
International Application No. WO 02/18437. The agonist of the
melanocortin receptor may preferably be selective for MC4-R.
[0216] In an embodiment of the composition above, the additional
compounds useful for the treatment of sexual dysfunction are
preferably selected from but not limited to the group consisting of
a phosphodiesterase inhibitor; a cyclic-GMP-specific
phosphodiesterase inhibitor; prostaglandins; apomorphin; oxytocin
modulators; .alpha.-adrenergic antagonists; dopanergic ligands;
androgens; selective androgen receptor modulators (SARMs);
buproprion; vasoactive intestinal peptide (VIP); neutral
endopeptidase inhibitors (NEP); neuropeptide Y receptor antagonists
(NPY); and bombesin receptor-3 antagonists.
[0217] In an embodiment of the method and composition, the second
sexual dysfunction pharmaceutical agent is testosterone.
[0218] In another embodiment of combination therapy, the second
sexual dysfunction pharmaceutical agent is a type V
phosphodiesterase inhibitor (PDE-5). For example, the PDE-5
inhibitor may be Viagra.RTM., a brand of sildenafil, Levitra.RTM.,
Clalis.RTM., or may be
1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1-H-pyrazolo[4,3-d]pyrimidin-5-
-yl]-4-ethoxy-phenyl]sulfonyl)-4-methylpiperazine citrate salt, as
disclosed in U.S. Published Application No. 2003/0083228.
[0219] In another embodiment of the composition above, the compound
useful for the treatment of sexual dysfunction is an estrogen
agonist/antagonist. In one embodiment, the estrogen
agonist/antagonist is
(-)-cis-6-phenyl-5-[-4-(2-pyrrolidin-1-yl-ethoxy)-phenyl]-5,6,7,8-tetrahy-
dro-napth-thalene-2-ol (also known as lasofoxifene) or an optical
or geometric isomer thereof; a pharmaceutically acceptable salt,
N-oxide, ester, quaternary ammonium salt; or a prodrug thereof.
More preferably, the estrogen agonist/antagonist is in the form of
a D-tartrate salt.
[0220] In yet another embodiment of the composition above, the
estrogen agonist/antagonist is selected from the group consisting
of tamoxifen, 4-hydroxy tamoxifen, raloxifene, droloxifene,
toremifene, centchroman, idoxifene,
6-(4-hydroxy-phenyl)-5-[4-(2-piperidine-1-yl-ethoxy)-benzyl]-napthalen-2--
ol,
{4-[2-(2-aza-bicyclo[2.2.1]hept-2-yl)-ethoxy]-phenyl}-[6-hydroxy-2-(4--
hydroxy-phenyl)-benzo[b]thiopehn-3-yl]-methanone, EM-652, EM-800,
GW 5368, GW 7604, TSE-424 and optical or geometric isomers thereof;
and pharmaceutically acceptable salts, N-oxides, esters, quaternary
ammonium salts, and prodrugs thereof.
[0221] In yet another embodiment, a compound of this invention may
be used in combination with any known mechanical aids or
devices.
[0222] The present invention also provides kits for the treatment
of sexual dysfunction (including erectile dysfunction), the kits
comprising: a first pharmaceutical composition including a compound
of this invention; a second pharmaceutical composition comprising a
second compound useful for the treatment of sexual dysfunction;
and, a container for the first and second compositions.
[0223] Female Sexual Dysfunction. The compounds of this invention
may be used to treat female sexual dysfunction as well as male
sexual dysfunction. In general, the dosing schedules and doses for
females are comparable to those for males.
[0224] The compounds of this invention, in that they are not
specific for any heretofore known melanocortin receptor, may
thereby define a new class of receptor, which receptor may be a
protein receptor or may be an enzyme-associated receptor. The
invention thus includes other compounds and structures that are
functionally equivalent to the compounds of this invention. These
other compounds are similarly characterized as effective in
inducting erectile activity, preferably at very low doses, without
being specific for any known melanocortin receptor.
[0225] Formulation and Utility
[0226] The methods, compounds and pharmaceutical compositions of
this invention can be used for both medical applications and animal
husbandry or veterinary applications
[0227] Salt Form of Compounds. The compounds of this invention may
be in the form of any pharmaceutically acceptable salt. The term
"pharmaceutically acceptable salts" refers to salts prepared from
pharmaceutically acceptable non-toxic bases or acids including
inorganic or organic bases and inorganic or organic acids. Salts
derived from inorganic bases include aluminum, ammonium, calcium,
copper, ferric, ferrous, lithium, magnesium, manganic salts,
manganous, potassium, sodium, zinc, and the like. Particularly
preferred are the ammonium, calcium, lithium, magnesium, potassium,
and sodium salts. Salts derived from pharmaceutically acceptable
organic non-toxic bases include salts of primary, secondary, and
tertiary amines, substituted amines including naturally occurring
substituted amines, amines, and basic ion exchange resins, such as
arginine, betaine, caffeine, choline, N,N'-dibenzylethylenediamine,
diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol,
ethanolamine, ethylenediamine, N-ethyl-morpholine,
N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine,
isopropylamine, lysine, methylglucamine, morpholine, piperazine,
piperidine, polyamine resins, procaine, purines, theobromine,
triethylamine, trimethylamine, tripropylamine, tromethamine, and
the like.
[0228] When the compound of the present invention is basic, acid
addition salts may be prepared from pharmaceutically acceptable
non-toxic acids, including inorganic and organic acids. Such acids
include acetic, benzenesulfonic, benzoic, camphorsulfonic,
carboxylic, citric, ethanesulfonic, formic, fumaric, gluconic,
glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic,
malic, mandelic, methanesulfonic, malonic, mucic, nitric, pamoic,
pantothenic, phosphoric, propionic, succinic, sulfuric, tartaric,
p-toluenesulfonic acid, trifluoroacetic acid, and the like. Acid
addition salts of the compounds of this invention are prepared in a
suitable solvent from the compound and an excess of an acid, such
as hydrochloric, hydrobromic, sulfuric, phosphoric, acetic,
trifluoroacetic, citric, tartaric, maleic, succinic or
methanesulfonic acid. The acetate salt form is especially useful.
Where the compounds of this invention include an acidic moiety,
suitable pharmaceutically acceptable salts may include alkali metal
salts, such as sodium or potassium salts, or alkaline earth metal
salts, such as calcium or magnesium salts.
[0229] Pharmaceutical Compositions. The invention provides a
pharmaceutical composition that includes a compound of this
invention and a pharmaceutically acceptable carrier. The carrier
may be a liquid formulation, and is preferably a buffered,
isotonic, aqueous solution. Pharmaceutically acceptable carriers
also include excipients, such as diluents, carriers and the like,
and additives, such as stabilizing agents, preservatives,
solubilizing agents, buffers and the like, as hereafter
described.
[0230] The compositions of this invention may be formulated or
compounded into pharmaceutical compositions that include at least
one compound of this invention together with one or more
pharmaceutically acceptable carriers, including excipients, such as
diluents, carriers and the like, and additives, such as stabilizing
agents, preservatives, solubilizing agents, buffers and the like,
as may be desired. Formulation excipients may include
polyvinylpyrrolidone, gelatin, hydroxy cellulose, acacia,
polyethylene glycol, manniton, sodium chloride and sodium citrate.
For injection or other liquid administration formulations, water
containing at least one or more buffering constituents is
preferred, and stabilizing agents, preservatives and solubilizing
agents may also be employed. For solid administration formulations,
any of a variety of thickening, filler, bulking and carrier
additives may be employed, such as starches, sugars, fatty acids
and the like. For topical administration formulations, any of a
variety of creams, ointments, gels, lotions and the like may be
employed. For most pharmaceutical formulations, non-active
ingredients will constitute the greater part, by weight or volume,
of the preparation. For pharmaceutical formulations, it is also
contemplated that any of a variety of measured-release,
slow-release or time-release formulations and additives may be
employed, so that the dosage may be formulated so as to effect
delivery of a compound of this invention over a period of time.
[0231] In general, the actual quantity of compounds of this
invention administered to a patient will vary between fairly wide
ranges depending on the mode of administration, the formulation
used, and the response desired.
[0232] In practical use, the compounds of the invention can be
combined as the active ingredient in an admixture with a
pharmaceutical carrier according to conventional pharmaceutical
compounding techniques. The carrier may take a wide variety of
forms depending on the form of preparation desired for
administration, for example, oral, parenteral (including
intravenous), urethral, vaginal, nasal, buccal, sublingual, or the
like. In preparing the compositions for oral dosage form, any of
the usual pharmaceutical media may be employed, such as, for
example, water, glycols, oils, alcohols, flavoring agents,
preservatives, coloring agents and the like in the case of oral
liquid preparations, such as, for example, suspensions, elixirs and
solutions; or carriers such as starches, sugars, microcrystalline
cellulose, diluents, granulating agents, lubricants, binders,
disintegrating agents and the like in the case of oral solid
preparations such as, for example, powders, hard and soft capsules
and tablets.
[0233] Because of their ease of administration, tablets and
capsules represent an advantageous oral dosage unit form. If
desired, tablets may be coated by standard aqueous or nonaqueous
techniques. The amount of active compound in such therapeutically
useful compositions is such that an effective dosage will be
obtained. In another advantageous dosage unit form, sublingual
constructs may be employed, such as sheets, wafers, tablets or the
like. The compounds can also be administered intranasally as, for
example, by liquid drops or spray.
[0234] The tablets, pills, capsules, and the like may also contain
a binder such as gum tragacanth, acacia, corn starch or gelatin;
excipients such as dicalcium phosphate; a disintegrating agent such
as corn starch, potato starch or alginic acid; a lubricant such as
magnesium stearate; and a sweetening agent such as sucrose, lactose
or saccharin. When a dosage unit form is a capsule, it may contain,
in addition to materials of the above type, a liquid carrier such
as a fatty oil.
[0235] Various other materials may be utilized as coatings or to
modify the physical form of the dosage unit. For instance, tablets
may be coated with shellac, sugar or both. A syrup or elixir may
contain, in addition to the active ingredient, sucrose as a
sweetening agent, methyl and propylparabens as preservatives, a dye
and a flavoring such as cherry or orange flavor.
[0236] Compounds may also be administered parenterally. Solutions
or suspensions of compounds can be prepared in water suitably mixed
with a surfactant such as hydroxy-propylcellulose. Dispersions can
also be prepared in glycerol, liquid polyethylene glycols and
mixtures thereof in oils. These preparations may optionally contain
a preservative to prevent the growth of microorganisms.
[0237] The pharmaceutical forms suitable for injectable use include
sterile aqueous solutions or dispersions and sterile powders for
the extemporaneous preparation of sterile injectable solutions or
dispersions. In all cases, the form must be sterile and must be
fluid to the extent that it may be administered by syringe. The
form must be stable under the conditions of manufacture and storage
and must be preserved against the contaminating action of
microorganisms such as bacteria and fungi. The carrier can be a
solvent or dispersion medium containing, for example, water,
ethanol, a polyol, for example glycerol, propylene glycol or liquid
polyethylene glycol, suitable mixtures thereof, and vegetable
oils.
[0238] The compounds of this invention may be therapeutically
applied by means of nasal administration. By "nasal administration"
is meant any form of intranasal administration of any of the
compounds of this invention. The compounds may be in an aqueous
solution, such as a solution including saline, citrate or other
common excipients or preservatives. The compounds may also be in a
dry or powder formulation.
[0239] In an alternative embodiment, compounds of this invention
may be administered directly into the lung. Intrapulmonary
administration may be performed by means of a metered dose inhaler,
a device allowing self-administration of a metered bolus of a
compound of this invention when actuated by a patient during
inspiration.
[0240] Routes of Administration. If it is administered by
injection, the injection may be intravenous, subcutaneous,
intramuscular, intraperitoneal or other means known in the art. The
compounds of this invention may be formulated by any means known in
the art, including but not limited to formulation as tablets,
capsules, caplets, suspensions, powders, lyophilized preparations,
suppositories, ocular drops, skin patches, oral soluble
formulations, sprays, aerosols and the like, and may be mixed and
formulated with buffers, binders, excipients, stabilizers,
anti-oxidants and other agents known in the art. In general, any
route of administration by which the compounds of invention are
introduced across an epidermal layer of cells may be employed.
Administration means may thus include administration through mucous
membranes, buccal administration, oral administration, dermal
administration, inhalation administration, nasal administration,
urethral administration, vaginal administration, and the like.
[0241] Therapeutically Effective Amount. In general, the actual
quantity of compound of this invention administered to a patient
will vary between fairly wide ranges depending upon the mode of
administration, the formulation used, and the response desired. The
dosage for treatment is administration, by any of the foregoing
means or any other means known in the art, of an amount sufficient
to bring about the desired therapeutic effect. Thus a
therapeutically effective amount includes an amount of a compound
or pharmaceutical composition of this invention that is sufficient
to induce a sexual response, including inducing a penile erection
in a male mammal.
[0242] In general, the compounds of this invention are highly
active, with dose responses as low as 0.1 .mu.g/kg, and optimal or
peak dose responses typically between about 0.1 .mu.g/kg and 25
.mu.g/kg, depending on the specific compound and the route of
administration. For example, the compound can be administered at
0.01, 0.05, 0.1, 0.5, 1, 5, 10, 50, 100, or 500 .mu.g/kg body
weight, depending on specific compound selected, the desired
therapeutic response, the route of administration, the formulation
and other factors known to those of skill in the art. Conventional
dose response studies and other pharmacological means may be
employed to determine the optimal dose for a desired effect with a
given compound, given formulation and given route of
administration.
[0243] Melanocortin Receptor Binding Assays. In a preferred
embodiment, the compounds of the invention are characterized, in
part, in that they do not inhibit, or do not substantially inhibit,
the binding of .alpha.-MSH or an .alpha.-MSH analog to melanocortin
receptors, and specifically MC1-R, MC3-R, MC4-R or MC5-R, such as
by means of a competitive inhibition binding assay, where the
concentration of the compound is at 1 .mu.M. Thus the compound does
not inhibit or substantially the binding of .alpha.-MSH or an
.alpha.-MSH analog to MC4-R, where the concentration of the
compound is at 1 .mu.M. NDP-MSH is one example of an .alpha.-MSH
analog. Similarly, in a preferred embodiment the compound does not
inhibit or substantially inhibit the binding of .alpha.-MSH or an
.alpha.-MSH analog to MC3-R, where the concentration of the
compound is at 1 .mu.M. Most preferably the compound is further not
a melanocortin receptor agonist, and is specifically not a MC4-R
agonist or a MC3-R agonist.
[0244] A competitive inhibition binding assay can be employed to
determine inhibition of binding of .alpha.-MSH or an .alpha.-MSH
analog, such as by using membranes prepared from hMC3-R, hMC4-R,
hMC5-R, and B-16 mouse melanoma cells (containing MC1-R) using 0.4
nM .sup.125I-NDP-MSH (0.2 nM for MC1-R) (New England Nuclear,
Boston, Mass., USA) in 50 mM HEPES buffer containing 1 mM
MgCl.sub.2, 2 mM CaCl.sub.2, and 5 mM KCl, at pH 7.2. The assay
tube contains a chosen concentration of the compound of this
invention, most preferably 1 .mu.M, for determining inhibition of
the binding of .sup.125I-NDP-MSH to its receptor. Non-specific
binding is measured by complete inhibition of binding of
.sup.125I-NDP-MSH in the assay in the presence of 1 .mu.M
.alpha.-MSH. Incubation is for 90 minutes at 37.degree. C., after
which the assay mixture is filtered and the membranes washed three
times with ice cold buffer. The filter is dried and counted in a
gamma counter for remaining radioactivity bound to the membranes.
100% specific binding is defined as the difference in radioactivity
(cpm) bound to cell membranes in the absence and presence of 1
.mu.M .alpha.-MSH. The cpm obtained in the presence of compounds of
this invention is normalized with respect to 100% specific binding
to determine the percent inhibition of .sup.125I-NDP-MSH
binding.
[0245] A compound does not "inhibit" .alpha.-MSH binding,
determined by inhibition of binding of .sup.125I-NDP-MSH, when the
measured percent inhibition is less than about 10%, and preferably
when no inhibition is detectable (the measured percent inhibition
is 0% or less), where the concentration of the compound is at 1
.mu.M. A compound does not "substantially inihibit" .alpha.-MSH
binding when the measured percent inhibition is less than about
40%, where the concentration of the compound is at 1 .mu.M.
[0246] Functional assays to determine agonist or antagonist status
of a compound may be conducted by any means known in the art. In
one method, a cAMP assay is performed. Human MC4-R cells are grown
to confluence in 96 well plates (plating approximately 250,000
cells per well). Identical sets of cells in triplicate are treated
with 0.2 mM isobutylmethylxanthine (IBMX) and the chosen
concentration of the compound or alternatively the compound in the
presence of 20 nM NDP-MSH. Cells similarly treated but with only 20
nM NDP-MSH serve as positive control. A buffer blank, as a negative
control, is also included. Incubation is for one hour at 37.degree.
C. after which the cells are lysed by the addition of 50 .mu.L of a
cell lysis buffer. Total cAMP accumulated in 250 .mu.L of this
solution is quantitated using a commercially available low pH cAMP
assay kit (Amersham BioSciences) by the procedure specified by the
kit supplier. Any test subject showing cAMP accumulation in the
same range as or higher than the positive control (buffer blank in
the presence of .alpha.-MSH) is considered to be an agonist. A test
subject showing accumulation in the same range as the negative
control (buffer blank in the absence of .alpha.-MSH) is ineffective
at the test concentration if the result is similar to the positive
control where .alpha.-MSH is also present in the assay. A test
subject showing accumulation in the same range as the negative
control is considered to be an antagonist if there is inhibition in
cAMP when .alpha.-MSH is present in the assay. Similar methods may
be employed for MC3-R, using MC3-R cells. Compounds of this
invention are, in one particularly preferred embodiment,
ineffective at any concentration, and thus are neither an agonist
nor an antagonist with respect to MC4-R.
[0247] In a particularly preferred embodiment, the compounds of the
invention are effective for treatment of sexual dysfunction but do
not cause a biologically response associated with activation or
inhibition of a melanocortin receptor, such as at 1 .mu.M
concentration or lower, particularly MC3-R and/or MC4-R, and thus
do not modulate feeding behavior in mammals or elicit or cause
other responses characteristic of MC4-R specific molecules,
including without limitation treatment of obesity or diabetes
mellius such as associated with MC3-R or MC4-R specific agonists,
or treatment of cachexia or wasting disease associated with cancer,
AIDS, failure to thrive syndrome, and diseases associated with
aging and senility such as associated with MC4-R specific
antagonists.
[0248] The invention is further illustrated by the following
non-limiting examples.
Example 1
[0249] A competitive inhibition binding assay is conducted using
membranes prepared from hMC3-R, hMC4-R, hMC5-R, and B-16 mouse
melanoma cells (containing MC1-R) using 0.4 nM
.sup.125I-NDP-.alpha.-MSH (New England Nuclear, Boston, Mass., USA)
in 50 mM HEPES buffer containing 1 mM MgCl.sub.2, 2 mM CaCl.sub.2,
and 5 mM KCl, at pH 7.2. The assay tube also contains a chosen
concentration of the test compound of this invention, preferably a
concentration of 1 .mu.M, for determining its efficacy in
inhibiting the binding of .sup.125I-NDP-.alpha.-MSH to its
receptor. Non-specific binding is measured by complete inhibition
of binding of .sup.125I-NDP-.alpha.-MSH in the assay with the
presence of 1 .mu.M .alpha.-MSH.
[0250] Incubation is for 90 minutes at room temperature, after
which the assay mixture was filtered and the membranes washed three
times with ice cold buffer. The filter is dried and counted in a
gamma counter for remaining radioactivity bound to the membranes.
100% specific binding is defined as the difference in radioactivity
(cpm) bound to cell membranes in the absence and presence of 1
.mu.M .alpha.-MSH. The cpm obtained in presence of test compounds
are normalized with respect to 100% specific binding to determine
the percent inhibition of .sup.125I-NDP-.alpha.-MSH binding. Each
assay is conducted in triplicate and the actual mean values are
described.
Example 2
[0251] Functional evaluation of compounds at melanocortin receptors
is performed by measuring the accumulation of intracellular cAMP in
HEK-293 cells expressing MC3-R, MC4-R or MC5-R, and in B-16 mouse
melanoma cells (containing MC1-R). Cells, suspended in Earle's
Balanced Salt Solution containing 10 mM HEPES, pH 7.5, 5 mM
MgCl.sub.2, 1 mM glutamine, 0.1% albumin and 0.6 mM
3-isobutyl-1-methyl-xanthine, a phosphodiesterase inhibitor, are
plated in 96 well plates at a density of 0.5.times.10.sup.5 cells
per well. Cells are incubated with the test compounds, preferably
at a concentration of 1 .mu.M, in the presence or absence of
.alpha.-MSH for 1 hour at 37.degree. C. cAMP levels are measured by
EIA (Amersham) in the cell lysates. Data analysis and EC.sub.50
values are determined using nonlinear regression analysis with
Prism Graph-Pad software.
Example 3
[0252] The agonist/antagonist status with respect to MC4-R of
certain compounds of the invention is determined. Antagonistic
activity is determined by measuring the inhibition of
.alpha.-MSH-induced cAMP levels following exposure to the compounds
as in Example 2.
Example 4
[0253] The ability of compounds to induce penile erection (PE) in
male rats is evaluated with selected compounds. Male Sprague-Dawley
rats weighing 200-250 g are kept on a 12 hour on/off light cycle
with food and water ad libitum. All behavioral studies are
performed between 10 a.m. and 5 p.m. Groups of 4-8 rats are treated
with compounds at a variety of doses via intravenous (IV) or
intracerebroventricular (ICV) routes. Immediately after treatment,
rats are placed into individual polystyrene cages (27 cm long, 16
cm wide, and 25 cm high) for behavioral observation. Rats are
observed for 30 minutes (for IV treated rats) or 120 minutes (for
ICV treated rats) and the number of yawns, grooming bouts and PEs
are recorded in 10-minute bins.
Example 5
[0254] Change in food intake and body weight are evaluated for
selected compounds. Male Sprague-Dawley rats weighing .about.300 g
at the beginning of the experiment are kept on a 12 hour on/off
light cycle. Lights out is adjusted to 12:00 p.m. to allow for
dosing just prior to the start of their dark period. Rats
(8-12/group) were fed powdered chow and water ad libitum. For 1
week before treatment, 24-hour food intake and body weight change
is recorded to assess a baseline for the group during vehicle
treatment. The rats are dosed ICV with vehicle or selected
compounds (1-3 nmol) or IV with vehicle or selected compounds
(0.5-3 mg/kg). The changes in body weight and food intake for the
24 hour period after dosing are determined. The changes in body
weight and food intake for the 48 hour period, and in some cases
the 72 hour period, after dosing is also measured to determined
reversal of changes in body weight and food intake effect back to
baseline.
Example 6
[0255] The following compound of formula VIII:
##STR00012##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 1:
[0256] To N-(tert-butoxycarbonyl)-L-tryprophan, N-methyl morpholine
(1 equivalent) in dry DCM is added TBTU (1 equivalent). The mixture
is stirred at room temperature for 30 minutes. A mixture of
N,O-dimethylhydroxyamine hydrochloride (1.5 equivalent) and NMM
(1.5 equivalent) in DCM is stirred for 30 minutes. These two
mixtures are combined and stirred at room temperature for 18 hours.
The organic solvent is evaporated and the residue is purified by
flash chromatography to give N-(tert-butoxycarbonyl)-tryprophan,
N,O-dimethyl-hydroxamide. The resulting
N-(tert-butoxycarbonyl)-tryprophan, N,O-dimethyl-hydroxamide is
dissolved in dry THF. The solution is cooled to 0.degree. C. under
nitrogen atmosphere. To this solution is added LAH (1 M in THF,
1.25 equivalent) slowly. The solution is stirred at this
temperature for 30 minutes. The reaction is stopped by adding
potassium hydrogensulfate (1.5 equivalent) in water. After stirring
for 30 minutes, the solvent is removed and re-dissolved in ether.
The organic phase is washed by 1 N hydrochloric acid, saturated
sodium hydrogen carbonate and brine. The ether layer is dried over
sodium sulfate. Solvent is removed to give an aldehyde derivative
A, which is used for next step reaction without further
purification.
[0257] Compounds A and
N-methoxy-N-methyl-2-(triphenylphosphoranylidene)acetamide (2
equivalent) in methylene chloride are stirred for 16 hours. The
solvent is evaporated and the residue is purified on a silica gel
column to give a compound mainly with (E)-olefin. This compound is
subsequently subjected to the treatment by hydrogen with catalytic
amount of Pd on carbon (10%) in EtOAc for 10 hours. After
filtration and evaporation of solvent compound B is obtained for
the next step reaction without further purification.
[0258] Compound B is treated with 25% TFA in methylene chloride for
one hour. The solvent is removed. The compound is neutralized by
N-methylmorpholine, which is then added to a mixture of Z-Ala-OH,
N-methyl morpholine (1 equivalent) and TBTU (1 equivalent) in dry
DCM. The reaction is carried out for 16 hours at room temperature.
Solvent is removed and the residue purified on silica gel column to
give compound C.
[0259] Compound C is dissolved in dry THF. The solution is cooled
to 0.degree. C. under nitrogen atmosphere. To this solution is
added LAH (1 M in THF, 1.25 equivalent) slowly. The solution is
stirred at this temperature for 30 minutes. The reaction is stopped
by adding potassium hydrogen sulfate (1.5 equivalent) in water.
After stirring for 30 minutes, the solvent is removed and
re-dissolved in ether. The organic phase is washed with 1 N
hydrochloric acid, saturated sodium hydrogencarbonate and brine.
The ether layer is dried over sodium sulfate. Solvent is removed to
give an aldehyde derivative, which is then used for next step
reaction without further purification.
[0260] The aldehyde derivative is dissolved in DCM containing
catalytic amounts of TFA. The solution is refluxed for 5 hours.
After removing solvent, the residue is purified on column to give
Cbz-protected compound D, which is dissolved in methanol in the
presence of catalytic amount of palladium on carbon (10%). The
mixture is stirred under hydrogen (1 atmosphere) overnight. After
filtration and evaporation of solvent, the residue is dried under
vacuum to give compound D.
[0261] Compound D is coupled with desired amino acids (2
equivalent) by use of HOAt (2 equivalent) and DIC (2 equivalent) in
N,N-dimethylformamide solution overnight at room temperature. Flash
chromatography (EtOAc/hexane=2) gives the product with protecting
groups. The Fmoc protecting group is removed by treatment with 20%
diethyl amine in EtOAc and the Boc protecting group is removed by
treatment with 30% TFA in methylene chloride for 1 hour, as
applicable to the compounds. The final pure compound E is obtained
by purification on HPLC.
##STR00013##
[0262] To make the compound of Example 6, compound D is coupled
with Boc-D-Phe(4-Cl) as described and the Boc group is removed by
treatment with 30% TFA in methylene chloride for 1 hour as
described.
[0263] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 7
[0264] The following compound of formula VI wherein R.sub.2 is H
and R.sub.4 and R.sub.5 are each --CH.sub.3:
##STR00014##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 2:
[0265] To a solution of Indole-3-AcOH and HOAt (1 equivalent) in
dry N,N-dimethylformamide is added
1-(3-dimethylaminopropyl)-3-ethylcarbodimide hydrochloride (2
equivalent). After the mixture is stirred at room temperature for
half an hour, 2-amino-3-butanol (2 equivalent) is added. The
reaction is continued for 16 hours. The reaction mixture is poured
into water and extracted by EtOAc twice. The organic layer is
washed by 1 N hydrochloric acid twice, 1 N sodium hydroxide twice,
brine and dried over sodium sulfate. After evaporating the solvent,
the product is purified on silica gel column with 10% methanol on
methylene chloride. To this compound (1 equivalent) and sodium
borohydride (5 equivalent) in dioxane is added AcOH (5 equivalent)
in dioxane slowly. After completion the mixture is refluxed for 2
hours, and the reaction is quenched by water. The product is
extracted from ether by 1 N hydrochloric acid. The pH value of the
aqueous solution is adjusted with potassium hydroxide to around 11
and the product is extracted by ether three times. The organic
layer is dried over sodium sulfate and solvent is evaporated. The
obtained compound A is used for next step reaction without further
purification.
[0266] To compound B (1 equivalent), N-methyl morpholine (1
equivalent) in dry DCM, is added TBTU (1 equivalent). The mixture
is stirred at room temperature for 30 minutes. A mixture of
N,O-dimethylhydroxyamine hydrochloride (1.5 equivalent) and NMM
(1.5 equivalent) in DCM is stirred for 30 minutes. These two
mixtures are combined and stirred at room temperature for 18 hours.
The organic solvent is evaporated, the residue loaded on a flash
chromatography column and eluted with ethyl acetae/hexane (2/1) to
give an N,O-dimethylhydroxyamide product. This product is dissolved
in dry THF at 0.degree. C. and LAH (1 M in THF, 1.2 equivalent) is
added slowly. After 30 minutes the reaction is quenched by aqueous
potassium hydrogen sulfate (1.2 equivalent). THF is removed and
ether added. The solution is washed by 1 N HCl (2 times), aqueous
sodium hydrogen carbonate, and subsequently brine, and dried over
sodium sulfate. The solvent is removed under vacuum to give
compound C. Compound C is used for next step reaction without
further purification.
[0267] A mixture of compound C and compound A is stirred in the
presence of activated 4 .ANG. molecular sieves (1 gram) in dry THF
(10% AcOH) for 1 hour. Sodium cyanoborohydride (1 equivalent, 1 M
solution in THF) is added to this mixture. After 2 hours, solvent
is evaporated and the desired product D is purified by silica gel
column.
[0268] Compound D is treated with 20% diethylamine in EtOAc for 12
hours and the solvent evaporated to dryness. The residue and TPP (3
equivalent) is dissolved in dry THF. To this solution is added DIAD
(3 equivalent) in THF slowly at 0.degree. C. The reaction is
continued for 16 hours at room temperature. The resulting product E
is purified by silica gel column after evaporation of solvent.
[0269] Compound E is coupled with the desired amino acid(s) (2
equivalent) by use of HOAt (2 equivalent) and DIC (2 equivalent) in
N,N-dimethylformamide solution overnight at room temperature. Flash
chromatography (EtOAc/hexane=2) gives the product with protection
groups. The Fmoc group is removed by treatment with 20% diethyl
amine in EtOAc, or alternatively the Boc group is removed by
treatment with 30% TFA in methylene chloride for 1 hour, as
applicable to the compounds. The final pure compounds F are
obtained by purification on HPLC.
##STR00015##
[0270] To make the compound of Example 7, compound E is coupled
with Boc-L-Phe(2,4-di-Cl) as described and the Boc group is removed
by treatment with 30% TFA in methylene chloride for 1 hour as
described.
[0271] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 8
[0272] The following compound of formula V:
##STR00016##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 3:
[0273] To a solution of Fmoc-Norleucine alcohol A in DCM is added
1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one (1.1
equivalent) in portions. After stirring for 30 minutes at room
temperature, the solution is diluted by ether, followed by addition
of 25% sodium thiosulphate in an aqueous solution saturated with
sodium bicarbonate. The mixture is stirred for an additional 5
minutes and the desired compound extracted by EtOAc. The organic
layer is washed by saturated bicarbonate solution, water and
subsequently dried over magnesium sulfate. After evaporation of
solvent, compound B is obtained for the next step reaction without
further purification.
[0274] A mixture of compound B, R- or S-amino acid methyl ester (1
equivalent), or another selected amino acid methyl ester, such as
an alpha amino acid with its side chain appearing as R.sub.5 in the
final compound F, TEA (1 equivalent) in the presence of a 4 .ANG.
molecular sieve in dry THF is stirred for two hours. After addition
of sodium triacetoxyborohydride (1.5 equivalent) the mixture is
stirred for an additional 16 hours. The solid is removed by
filtration and the product extracted by EtOAc from water. The
organic layer is dried over sodium sulfate. After evaporation of
solvent the residue is dissolved in EtOAc containing 20%
diethylamine. The reaction is carried out for 16 hours and solvent
removed under vacuum. The product C is obtained after purification
by chromatography.
##STR00017##
[0275] To a solution of desired carboxylic acid (1 equivalent), or
a related acid constituting itself as R.sub.1 in the final compound
F, and N-methylmorpholine (1 equivalent) in DCM at -15.degree. C.
is added isopropyl chloroformate (1 equivalent) slowly. The
reaction mixture is stirred for 30 minutes and compound C is
subsequently added. After 30 minutes the reaction temperature is
raised to room temperature and the mixture stirred for 16 hours.
The solvent is evaporated and the residue purified on column to
give compound D.
[0276] To a solution of compound D in THF is added LAH (in THF, 4.5
equivalent) slowly. The reaction is conducted at room temperature
for 2 hours and refluxing temperature for 16 hours. After cooling,
the reaction mixture is treated with water, 15% sodium hydroxide
and subsequently water. The white solids are removed by filtration
and solvent is evaporated. The residue contains compound E, which
is used for the next step reaction without further
purification.
[0277] Compound E is coupled with desired amino acids (2
equivalent) by use of HOAt (2 equivalent) and DIC (2 equivalent) in
N,N-dimethylformamide solution overnight at room temperature to
introduce the desired R.sub.3 moiety in the molecule. Flash
chromatography gives the product with protecting groups. Fmoc
groups are removed by treatment with 20% diethyl amine in EtOAc and
Boc groups are removed by treatment with 30% of TFA in methylene
chloride for 1 hour, as applicable to the specific compounds.
[0278] The final pure compound F is obtained by purification on
HPLC.
[0279] To make the compound of Example 8, Compound E is coupled
with Boc-Phe(4-Cl) as described and the Boc group is removed by
treatment with 30% TFA in methylene chloride for 1 hour as
described.
[0280] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 9
[0281] The following compound of formula III wherein X is
CH.sub.2:
##STR00018##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 4:
[0282] Compound A (1 equivalent), N-methyl morpholine (1
equivalent) in dry DCM, is added to TBTU (1 equivalent). The
mixture is stirred at room temperature for 30 minutes. A mixture of
N,O-dimethylhydroxyamine hydrochloride (1.5 equivalent) and NMM
(1.5 equivalent) in DCM is stirred for 30 minutes These two
mixtures are combined and stirred at room temperature for 18 hours.
The organic solvent is evaporated, the residue loaded on a flash
chromatography column and eluted with ethyl acetae/hexane (2/1) to
give an N,O-dimethylhydroxyamide product. This product is dissolved
in dry THF at 0.degree. C. and LAH (1 M in THF, 1.2 equivalent) is
added slowly. After 30 minutes the reaction is quenched by aqueous
potassium hydrogen sulfate (1.2 equivalent). THF is removed and
ether added. The solution is washed by 1 N HCl (2 times), aqueous
sodium hydrogen carbonate, and brine subsequently, and dried over
sodium sulfate. The solvent is removed under vacuum to give
compound B. Compound B is used for next step reaction without
further purification.
[0283] Compound B is mixed with sodium triacetoxyborohydride (1.2
equivalent) and ethanolamine (1.2 equivalent) in the presence of
activated 4 .ANG. molecular sieves (1 gram) in dry THF. The mixture
is stirred at room temperature for 6 hours and to it is added
N-(benzyloxycarbonyloxy)succinimide (2 equivalent). It is stirred
for an additional 24 hours. After filtration and evaporation of
solvent the desired product C is purified on silica gel column.
[0284] Compound C is treated with 20% diethylamine in EtOAc for 12
hours and the solvent evaporated to dryness. The residue and TPP (3
equivalent) is dissolved in dry THF. To this solution is added DIAD
(3 equivalent) in THF slowly at 0.degree. C. The reaction is
carried out for 16 hours at room temperature. The product D is
purified on silica gel column after evaporation of solvent.
[0285] Compound D is coupled with desired amino acids (2
equivalent) by use of HOAt (2 equivalent) and DIC (2 equivalent) in
N,N-dimethylformamide solution overnight at room temperature. Flash
chromatography (EtOAc/hexane=2) gives the product with protecting
groups E. To make the compound of Example 9, Compound D is coupled
with Boc-L-Phe(4-Cl) as described to give compound E.
[0286] Compound E is treated by hydrogen in the presence of
catalytic amount of palladium on carbon overnight in methanol.
After filtration and removal of solvent the residue is used for
reductive amination reaction with Indole-3-carboxyaldehye under the
conditions described in the synthesis of compound C. The resulting
compound is purified by silica gel column.
[0287] The Fmoc group is removed by treatment with 20% diethyl
amine in EtOAc and the Boc group, such as on Boc-L-Phe(4-Cl), is
removed by treatment 30% TFA in methylene chloride for 1 hour, as
applicable to the compounds. The final pure compounds F are
obtained by purification on HPLC.
##STR00019##
[0288] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 10
[0289] The following compound of formula II wherein R.sub.2 is H
and X is C.dbd.O:
##STR00020##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 5:
[0290] To a solution of compound A and HOAt (1 equivalent) in dry
N,N-dimethylformamide is added
1-(3-dimethylaminopropyl)-3-ethylcarbodimide hydrochloride (2
equivalent). After the mixture is stirred at room temperature for
half an hour, ethanolamine (2 equivalent) is added. The reaction is
continued for 16 hours. The reaction mixture is poured into water
and extracted by EtOAc twice. The organic layer is washed by 1 N
hydrochloric acid twice, 1 N sodium hydroxide twice, brine and
dried over sodium sulfate. After evaporating the solvent the
product B is purified on silica gel column with 10% methanol on
methylene chloride.
[0291] To compound B (1 equivalent) and sodium borohydride (5
equivalent) in dioxane is added AcOH (5 equivalent) in dioxane
slowly. After completion the mixture is refluxed for 2 hours. The
reaction is quenched by water. The product is extracted from ether
by 1 N hydrochloric acid. The pH value of the aqueous solution is
adjusted with potassium hydroxide to around 11 and the product
extracted by ether three times. The organic layer is dried over
sodium sulfate and solvent evaporated. The obtained compound C is
used for next step reaction without further purification.
[0292] A desired N-protected amino acid (1 equivalent), HOAt (1
equivalent) and DIC (1 equivalent) in N, N-dimethylformamide
solution is stirred for half an hour. To this solution is added
compound C and the mixture stirred overnight. After evaporating
solvent, compound D is obtained by silica gel column
purification.
[0293] The protecting group P (Fluorenylmethoxycarbonyl or Cbz) is
removed by either 20% diethyl amine in EtOAc or by hydrogen
catalyzed with 10% palladium on carbon. The resulting compound is
dissolved in dry THF with TPP (3 equivalent). To this solution is
added DEAD (3 equivalent) in THF slowly. The reaction is stirred
for an additional 12 hours. After the solvent is evaporated the
product E is purified on silica gel column by EtOAc/methanol
(4/1=v/v).
[0294] Compound E is coupled with desired amino acids (2
equivalent) by use of HOAt (2 equivalent) and DIC (2 equivalent) in
N,N-dimethylformamide solution overnight at room temperature. Flash
chromatography (EtOAc/hexane=2) gives the product with protecting
groups. The Fmoc group is removed by treatment with 20% diethyl
amine in EtOAc and the Boc group is removed by treatment with 30%
TFA in methylene chloride for 1 hour, as applicable to the
compound. The final pure compound is obtained by purification on
HPLC.
[0295] To make the compound of Example 10, Compound E is coupled
with Boc-Phe(4-Cl) as described and the Boc group is removed by
treatment with 30% TFA in methylene chloride for 1 hour as
described.
##STR00021##
[0296] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 11
[0297] The following compound of formula IX:
##STR00022##
is synthesized by conventional methods. Briefly, in synthesis the
following steps are employed, as set forth in Scheme 6:
[0298] To N-(tert-butoxycarbonyl)-glutamine benzyl ester and
N-methyl morpholine (1 equivalent) in dry DCM is added TBTU (1
equivalent). The mixture is stirred at room temperature for 30
minutes. A mixture of N,O-dimethylhydroxyamine hydrochloride (1.5
equivalent) and NMM (1.5 equivalent) in DCM is stirred for 30
minutes. These two mixtures are combined and stirred at room
temperature for 18 hours. The organic solvent is evaporated and the
residue loaded on a flash chromatography column and eluted with
EtOAc/hexane (2/1) to give
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxamide)-glutamine
benzyl ester.
[0299]
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxyamide)-glutamine
benzyl ester in methanol and a catalytic amount of palladium on
carbon (10%) is stirred under 1 atmosphere hydrogen overnight at
room temperature. After filtration and evaporation of solvent, a
clear oily product is obtained.
[0300] To
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxamide)-glutamine (3.9
g, 13.45 mM) and NMM (1 equivalent) in THF at -15.degree. C. is
added slowly a THF solution of IBCF (1 equivalent). The mixture is
stirred at this temperature for additional 30 minutes. A solution
of sodium borohydride (1.5 equivalent) in water is added in
portions to the THF solution. After 20 minutes, the temperature is
raised to room temperature and stirred for another 1 hour. The
organic solvent is evaporated and the residue purified on column
(10% methanol in DCM) to give
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxamide)-glutaminol.
[0301] To
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxamide)-glutaminol and
TEA (2 equivalent) in DCM at 0.degree. C. is added methanesulfonyl
chloride (2 equivalent) in DCM. The solution is stirred at
0.degree. C. for 20 minutes and at room temperature for additional
45 minutes. The solvent is evaporated and the product extracted
from water by EtOAc. The organic layer is washed by water and brine
and dried over sodium sulfate. After removing solvent, the yield of
mesylated product is about 100%.
[0302] Sodium hydride (1.5 equivalent) is washed by hexane. After
decanted hexane, dry DMF is added and the desired alcohol (1.5
equivalent) in DMF is added slowly at room temperature. The
solution is stirred for another 1 hour until no hydrogen is
released. The mesylated compound in DMF is mixed with the foregoing
solution and stirred at room temperature for 24 hours. The solution
is heated at 90.degree. C. for additional 24 hours. After cooling,
the solution is poured into water and extracted by EtOAc twice. The
combined organic layer is washed by water and brine and dried over
sodium sulfate. The organic solvent is removed and the residue
eluted by EtOAc/hexane (2/1) on a column to give O-alkylated
N-(tert-butoxycarbonyl)-5-(N,O-dimethyl-hydroxamide)-glutaminol,
compound A in Scheme 6.
[0303] Compound A is stirred in TFA/DCM(1/4:v/v) for one hour. The
solvent is removed and dried under vacuum. The residue is mixed
with NMM (4 equivalent) in DCM. To a DCM solution of Z-Ala-OH (2
equivalent) and NMM (2 equivalent) is added TBTU (2 equivalent) and
the mixture is stirred for 30 minutes. These two solutions are
combined and stirred overnight at room temperature. After
evaporating solvent and purification on a column by EtOAc,
O-alkylated
N--(N-benzyloxy-valyl)-5-(N,O-dimethyl-hydroxamide)-glutaminol is
obtained. O-alkylated
N--(N-Cbz-valyl)-5-(N,O-dimethyl-hydroxamide)-glutaminol is
dissolved in dry THF. The solution is cooled to 0.degree. C. under
nitrogen atmosphere. To this solution is added LAH (1 M in THF,
1.25 equivalent) slowly. The solution is stirred at this
temperature for 30 minutes. The reaction is stopped by adding
potassium hydrogen sulfate (1.5 equivalent) in water. After
stirring for 30 minutes, the solvent is removed and re-dissolved in
ether. The organic phase is washed by 1 N hydrochloric acid,
saturated sodium hydrogen carbonate and brine. The ether layer is
dried over sodium sulfate. Solvent is removed to give an aldehyde
derivative, which is used for the next step reaction without
further purification. The aldehyde derivative is dissolved in DCM
containing a catalytic amount of TFA. The solution is refluxed for
5 hours.
##STR00023##
[0304] After removing solvent, the residue is purified on a column
to give compound B. Compound B is dissolved in methanol in the
presence of catalytic amounts of palladium on carbon (10%). The
mixture is stirred under hydrogen (1 atmosphere) overnight. After
filtration and evaporation of solvent, the residue is dried under
vacuum to give 2,5-substituted
hexahydro-pyrrolo[1,2-a]imidazol-3-one. This compound is coupled
with desired amino acids (2 equivalent) by use of HOAt (2
equivalent) and DIC (2 equivalent) in N,N-dimethylformamide
solution overnight at room temperature.
[0305] To make the compound of Example 11, 2,5-substituted
hexahydro-pyrrolo[1,2-a]imidazol-3-one is coupled with
Boc-Phe(4-Cl) as described.
[0306] Flash chromatography (EtOAc/hexane=2) gives the product with
protecting groups. The Fmoc group is removed by treatment with 20%
diethyl amine in EtOAc and the Boc group removed by treatment with
30% TFA in methylene chloride for 1 hour, as applicable to the
compounds. The final pure compounds C are obtained by purification
on HPLC.
[0307] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 12
[0308] The following compound is synthesized by conventional
methods. Briefly, in synthesis the following steps are employed, as
set forth in Scheme 7:
##STR00024##
[0309] A mixture of ketone (1 equivalent), ethyl cyanoacetae (1
equivalent), ammonium acetate (0.2 equivalent) and AcOH (0.8
equivalent) is refluxed in toluene for 20 hours with a Dean-Stark
apparatus. The mixture is concentrated. The residue is diluted with
saturated sodium hydrogen carbonate and extracted with chloroform.
The organic layer is washed with brine and dried over magnesium
sulfate. After evaporation of solvent the residue is purified on
silica gel column. This purified compound is dissolved in ethanol.
To this solution is added sulfur powder (1 equivalent) and
diethylamine (1 equivalent). The solution is stirred at 65.degree.
C. for 2 hours. The solvent is removed and the residue is diluted
with brine and extracted with chloroform. The extract is washed
with brine and dried over magnesium sulfate. The solution is
concentrated and residue purified on silica gel column or
recrystallized from a suitable solvent to give compound A.
[0310] To make the compound of Example 12,
1-(1H-Indol-3-yl)-pentan-3-one is used as the starting material to
form compound A. 3-iodo-1-(4-chlorophenyl)propane is used to make
compound C from compounds B as described.
##STR00025##
[0311] A mixture of compound A and a desired isocyanate (1.2
equivalent) in pyridine is stirred at 45.degree. C. for 2 hours.
After removal of solvent the residue is suspended in methanol and
sodium methoxide (2.5 equivalent) is added. The mixture is stirred
at room temperature for 6 hours and acidified with 2 N hydrochloric
acid at 0.degree. C. The solvent is removed and the precipitates
(B) are collected. After washing with water compound B is dried
under vacuum.
[0312] A mixture of compound B, substituted benzyl chloride (1.2
equivalent), potassium carbonate (1.5 equivalent) and potassium
iodide (0.5 equivalent) in DMF is stirred at room temperature for 4
hours. The solvent is removed and the residue is partitioned
between chloroform and water. The aqueous phase is extracted with
chloroform. The combined organic phase is washed with brine and
dried over magnesium sulfate. After removal of solvent the residue
is recrystallized from a suitable solvent to give compound C.
[0313] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
Example 13
[0314] The following compound of formula VI wherein R.sub.2 and
R.sub.5 are H, and R.sub.4 is --CH.sub.3:
##STR00026##
is synthesized by conventional methods. Briefly, the compound is
synthesized as in Example 7, Alaninol is employed to make compound
A of Scheme 2, and resulting compound E is coupled with
Fmoc-L-Phe(4-Cl) as described. The Fmoc group of the product is
removed by treatment with 20% diethyl amine in EtOAc. The resulting
compound is coupled with Boc-Leu by the same method and the Boc
group is removed by treatment with 30% TFA in methylene chloride
for 1 hour as described
[0315] The compound is tested for competitive inhibition at
melanocortin receptors, Ki (nM) at melanocortin receptors,
functional status at melanocortin receptors, ability to induce
penile erection and food intake and body weight change, as in
Examples 1 to 5.
[0316] The preceding examples can be repeated with similar success
by substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in the
preceding examples.
[0317] Although the invention has been described in detail with
particular reference to these preferred embodiments, other
embodiments can achieve the same results. Variations and
modifications of the present invention will be obvious to those
skilled in the art and it is intended to cover in the appended
claims all such modifications and equivalents. The entire
disclosures of all references, applications, patents, and
publications cited above are hereby incorporated by reference.
* * * * *