Bicyclic melanocortin-specific compounds

1. A compound having the structure:

or a stereoisomer or pharmaceutically acceptable salt thereof,

wherein

R 1 is -L 1 -J;

R 2 is (CH 2 ) y —W;

R 3 is -L 2 -Q;

L 1 is a linker selected from the group consisting of —(CH 2 ) y —, —O—(CH 2 ) y —, —O—, —NH—(CH 2 ) y —, —(C═O)(CH 2 ) y —, —(C═O)—O—(CH 2 ) y — and —CH 2 (C═O)NH—;

J is a ring structure selected from the group consisting of substituted or unsubstituted aromatic carbocyclic rings, substituted or unsubstituted non-aromatic carbocyclic rings, substituted or unsubstituted aromatic fused carbobicyclic ring groups, substituted or unsubstituted aromatic carbocyclic ring groups wherein the rings are joined by a bond or —O—, and substituted or unsubstituted aromatic fused heterobicyclic ring groups; wherein in each instance the rings comprise 5 or 6 ring atoms;

W is a heteroatom unit with at least one cationic center, hydrogen bond donor or hydrogen bond acceptor wherein at least one atom is N;

L 2 is a linker selected from the group consisting of

Q is an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl;

R 4 is a unit selected from the group consisting of an amine capping group, an amino acid residue, and an amino acid residue with an amine capping group;

X is C═O;

z is 0; and

y is at each occurrence independently from 1 to 6.

2. The compound of claim 1 wherein J is a substituted or unsubstituted ring structure selected from the group consisting of

3. The compound of claim 1 wherein at least one ring comprising J is functionalized with one or more halogen, alkyl or aryl groups.

4. The compound of claim 1 wherein R 1 is selected from the group consisting of

5. The compound of claim 1 wherein R 1 is selected from the group consisting of

6. The compound of claim 1 wherein W comprises a cationic center selected from the group consisting of NH 2 and NH(C═NH)NH 2 .

7. The compound of claim 1 wherein W is selected from the group consisting of —NHCOCH 3 , —CONHCH 3 , —NH(C═NH)NHMe, —NH(C═NH)NHEt, —NH(C═NH)NHPr, —NH(C═NH)NHPr—I, —NH(C═NH)NH 2 ,

8. The compound of claim 1 wherein R 2 is selected from the group consisting of

9. The compound of claim 1 where Q is

and wherein R 5a and R 5b are optional ring substituents, and when one or both are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage.

10. The compound of claim 9 wherein the alkyl group is —CH 3 or —OCH 3 .

11. The compound of claim 1 wherein R 4 is an amine capping group selected from the groups consisting of hexyl, hexanoyl, heptanoyl, acetyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, benzyl, benzoyl, cinnamoyl, 12-Ado, 7′-amino heptanoyl, 6-Ahx, Amc, and 8-Aoc.

12. The compound of claim 1 wherein R 3 is a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl.

13. The compound of claim 1 wherein R 3 is a D-amino acid with an amine capping group and an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl.

14. The compound of claim 1 wherein R 3 is a dipeptide consisting of a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl and a second amino acid residue, wherein the D-amino acid is bonded to the ring nitrogen.

15. The compound of claim 1 wherein R 3 is a dipeptide consisting of a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl and a second amino acid residue with an amine capping group.

16. The compound of claim 1 wherein R 3 comprises a D-amino acid selected from the group consisting of Phe, Phe(2-Cl), Phe(4-Cl), Phe(2,4-diCl), Phe(2,4-diF), Phe(3,4-diCl), Phe(4-NO 2 ), Phe(4-Me), Phe(4-Phenyl), HPhe, pF-Phe, Phe(4-Br), Phe(4-CF 3 ), Phe(3,4-diF), Phe(4-I),Phe(4-Me), Phe(2-Me, 4-Cl), Phe(2-F, 4-Cl), Phe(2,4-diMe), Phe(2-Cl4-CF 3 ), and Phe(3,4-di-OMe).

17. The compound of claim 1 wherein R 3 comprises a D-amino acid selected from the group consisting of Pgl, Trp, Nal 1, Nal 2, Bip, Dip, Bpa, Ser(Bzl), Ser(2-Naphthyl), Ser(Phenyl), Ser(4-Cl-Phenyl), Ser(2-Cl-Phenyl), Ser(p-Cl-Phenyl), Lys(Z), Lys(Z-2′Br), Lys(Bz), Thr(Bzl), Cys(Bzl), (N-PhEt)Nal2, Phg, 3-Pya, Qal(2′), Sal, Tpi, Tyr(2,6-DiCl-Bzl) and Tyr(Bzl).

18. The compound of claim 1 wherein R 3 comprises a second amino acid residue that is a an L-amino acid selected from the group consisting of Abu, 2-Abz, 3-Abz, 4-Abz, Achc, Acpc, Aib, Amb, Arg(Tos), Asp(anilino), Asp(3-Cl-anilino), Asp(3,5-diCl-anilino), 11-Aun, AVA, Beta-hHyp(Bzl), Cha, Chg, Cmpi, Disc, Dpr(beta-Ala), GM, GBzA, B-Gpa, GVA(Cl), His, hSer, Ser(Bzl), Tic, hHyp, Hyp(Bzl), Inp, 2-Naphthylacetyl, (Nlys)Gly, OcHx, Pip, 4-phenylPro, 5-phenylPro, Pyr, Sar, Tle, Tiq, Atc, Igl, Hyp(O-2-Naphthyl), Hyp(O-Phenyl), 2-Aic, Idc, 1-Aic, Beta-homoSer(Bzl), Ser(O-2-Naphthyl), Ser(O-Phenyl), Ser(O-4-Cl-Phenyl), Ser(O-2-Cl-Phenyl), Thr(Bzl), Tic, Beta-homoThr(Bzl), Thr(O-2-Naphthyl), Thr(O-Phenyl), Thr(O-4-Cl-Phenyl) and Thr(O-2-Cl-Phenyl), Nle, Leu, lie, Val and Beta-Ala.

19. The compound of claim 1 wherein R 3 comprises an amine capping group selected from the group consisting of hexyl, hexanoyl, heptanoyl, acetyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, benzyl, benzoyl, 7′-amino heptanoyl, 12-Ado, 6-Ahx, Amc, and 8-Aoc.

20. A compound having the structure:

or a stereoisomer or pharmaceutically acceptable salt thereof,

wherein

R 1 is -L 1 -J;

R 2 is (CH 2 ) y —W;

R 3 is -L 2 -Q;

L 1 is a linker selected from the group consisting of —(CH 2 ) y —, —O—(CH 2 ) y —, —O—, —NH—(CH 2 ) y —, —(C═O)(CH 2 ) y —, —(C═O)—O—(CH 2 ) y —, and —CH 2 (C═O)NH—;

J is a ring structure selected from the group consisting of substituted or unsubstituted aromatic carbocyclic rings, substituted or unsubstituted non-aromatic carbocyclic rings, substituted or unsubstituted aromatic fused carbobicyclic ring groups, substituted or unsubstituted aromatic carbocyclic ring groups wherein the rings are joined by a bond or —O—, and substituted or unsubstituted aromatic fused heterobicyclic ring groups; wherein in each instance the rings comprise 5 or 6 ring atoms;

W is a heteroatom unit with at least one cationic center, hydrogen bond donor or hydrogen bond acceptor wherein at least one atom is N;

L 2 is a linker selected from the group consisting of

Q is an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl;

R 4 is a unit selected from the group consisting of an amine capping group, an amino acid residue, and an amino acid residue with an amine capping group; and

y is at each occurrence independently from 1 to 6;

wherein the carbon atoms marked with an asterisk can have any stereochemical configuration.

21. The compound of claim 20 wherein J is a substituted or unsubstituted ring structure selected from the group consisting of

22. The compound of claim 20 wherein at least one ring comprising J is functionalized with one or more halogen, alkyl or aryl groups.

23. The compound of claim 20 wherein R 1 is selected from the group consisting of

24. The compound of claim 20 wherein R 1 is selected from the group consisting of

25. The compound of claim 20 wherein W comprises a cationic center selected from the group consisting of NH 2 and NH(C═NH)NH 2 .

26. The compound of claim 20 wherein W is selected from the group consisting of —NHCOCH 3 , —CONHCH 3 , —NH(C═NH)NHMe, —NH(C═NH)NHEt, —NH(C═NH)NHPr, —NH(C═NH)NHPr—I, —NH(C═NH)NH 2 ,

27. The compound of claim 20 wherein R 2 is selected from the group consisting of

28. The compound of claim 20 where Q is

and wherein R 5a and R 5b are optional ring substituents, and when one or both are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage.

29. The compound of claim 28 wherein the alkyl group is —CH 3 or —OCH 3 .

30. The compound of claim 20 wherein R 4 is an amine capping group selected from the groups consisting of hexyl, hexanoyl, heptanoyl, acetyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, benzyl, benzoyl, cinnamoyl, 12-Ado, 7′-amino heptanoyl, 6-Ahx, Amc, and 8-Aoc.

31. The compound of claim 20 wherein R 3 is a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl.

32. The compound of claim 20 wherein R 3 is a D-amino acid with an amine capping group and an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl.

33. The compound of claim 20 wherein R 3 is a dipeptide consisting of a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl and a second amino acid residue, wherein the D-amino acid is bonded to the ring nitrogen.

34. The compound of claim 20 wherein R 3 is a dipeptide consisting of a D-amino acid including an aromatic carbocyclic ring selected from the group consisting of phenyl, substituted phenyl, naphthyl and substituted naphthyl and a second amino acid residue with an amine capping group.

35. The compound of claim 20 wherein R 3 comprises a D-amino acid selected from the group consisting of Phe, Phe(2-Cl), Phe(4-Cl), Phe(2,4-diCl), Phe(2,4-diF), Phe(3,4-diCl), Phe(4-NO 2 ), Phe(4-Me), Phe(4-Phenyl), HPhe, pF-Phe, Phe(4-Br), Phe(4-CF 3 ), Phe(3,4-diF), Phe(4-I), Phe(2-Cl, 4-Me), Phe(2-Me, 4-Cl), Phe(2-F, 4-Cl), Phe(2,4-diMe), Phe(2-Cl,4-CF 3 ), and Phe(3,4-di-OMe).

36. The compound of claim 20 wherein R 3 comprises a D-amino acid selected from the group consisting of Pgl, Trp, Nal 1, Nal 2, Bip, Dip, Bpa, Ser(Bzl), Ser(2-Naphthyl), Ser(Phenyl), Ser(4-Cl-Phenyl), Ser(2-Cl-Phenyl), Ser(p-Cl-Phenyl), Lys(Z), Lys(Z-2′Br), Lys(Bz), Thr(Bzl), Cys(Bzl), (N-PhEt)Nal2, Phg, 3-Pya, Qal(2′), Sal, Tpi, Tyr(2,6-DiCl-Bzl) and Tyr(Bzl).

37. The compound of claim 20 wherein R 3 comprises a second amino acid residue that is a an L-amino acid selected from the group consisting of Abu, 2-Abz, 3-Abz, 4-Abz, Achc, Acpc, Aib, Amb, Arg(Tos), Asp(anilino), Asp(3-Cl-anilino), Asp(3,5-diCl-anilino), 11-Aun, AVA, Beta-hHyp(Bzl), Cha, Chg, Cmpi, Disc, Dpr(beta-Ala), GM, GBzA, B-Gpa, GVA(Cl), His, hSer, Ser(Bzl), Tic, hHyp, Hyp(Bzl), Inp, 2-Naphthylacetyl, (Nlys)Gly, OcHx, Pip, 4-phenylPro, 5-phenylPro, Pyr, Sar, Tle, Tiq, Atc, Igl, Hyp(O-2-Naphthyl), Hyp(O-Phenyl), 2-Aic, Idc, 1-Aic, Beta-homoSer(Bzl), Ser(O-2-Naphthyl), Ser(O-Phenyl), Ser(O-4-Cl-Phenyl), Ser(O-2-Cl-Phenyl), Thr(Bzl), Tic, Beta-homoThr(Bzl), Thr(O-2-Naphthyl), Thr(O-Phenyl), Thr(O-4-Cl-Phenyl) and Thr(O-2-Cl-Phenyl), Nle, Leu, Ile, Val and Beta-Ala.

38. The compound of claim 20 wherein R 3 comprises an amine capping group selected from the group consisting of hexyl, hexanoyl, heptanoyl, acetyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, benzyl, benzoyl, 7′-amino heptanoyl, 12-Ado, 6-Ahx, Amc, and 8-Aoc.

39. A compound having the structure:

or a stereoisomer or pharmaceutically acceptable salt thereof,

wherein

R 1 is -L 1 -J;

R 2 is (CH 2 ) y —W;

R 4 is H or a unit selected from the group consisting of an amine capping group, a second amino acid residue, and a second amino acid residue with an amine capping group;

R 5a and R 5b are optional ring substituents, and when one or both are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage;

L 1 is a linker selected from the group consisting of —(CH 2 ) y —, —O—(CH 2 ) y —, —O—, —NH—(CH 2 ) y —, —(C═O)(CH 2 ) y —, —(C═O)—O—(CH 2 ) y —, and —CH 2 (C═O)NH—;

J is a ring structure selected from the group consisting of substituted or unsubstituted aromatic carbocyclic rings, substituted or unsubstituted non-aromatic carbocyclic rings, substituted or unsubstituted aromatic fused carbobicyclic ring groups, substituted or unsubstituted aromatic carbocyclic ring groups wherein the rings are joined by a bond or —O—, and substituted or unsubstituted aromatic fused heterobicyclic ring groups; wherein in each instance the rings comprise 5 or 6 ring atoms;

W is a heteroatom unit with at least one cationic center, hydrogen bond donor or hydrogen bond acceptor wherein at least one atom is N; and

y is at each occurrence independently from 1 to 6;

wherein the carbon atoms marked with an asterisk can have any stereochemical configuration.

40. The compound of claim 39 wherein J is a substituted or unsubstituted ring structure selected from the group consisting of

41. The compound of claim 39 wherein at least one ring comprising J is functionalized with one or more halogen, alkyl or aryl groups.

42. The compound of claim 39 wherein R 1 is selected from the group consisting of

43. The compound of claim 39 wherein R 1 is selected from the group consisting of

44. The compound of claim 39 wherein W comprises a cationic center selected from the group consisting of NH 2 and NH(C═NH)NH 2 .

45. The compound of claim 39 wherein W is selected from the group consisting of —NHCOCH 3 , —CONHCH 3 , —NH(C═NH)NHMe, —NH(C═NH)NHEt, —NH(C═NH)NHPr, —NH(C═NH)NHPr—I, —NH(C═NH)NH 2 ,

46. The compound of claim 39 wherein R 2 is selected from the group consisting of

47. The compound of claim 39 wherein R 4 comprises an amine capping group selected from the groups consisting of hexyl, hexanoyl, heptanoyl, acetyl, phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, benzyl, benzoyl, cinnamoyl, 12-Ado, 7′-amino heptanoyl, 6-Ahx, Amc, and 8-Aoc.

48. The compound of claim 39 wherein R 4 comprises a second amino acid residue that is a an L-amino acid selected from the group consisting of Abu, 2-Abz, 3-Abz, 4-Abz, Achc, Acpc, Aib, Amb, Arg(Tos), Asp(anilino), Asp(3-Cl-anilino), Asp(3,5-diCl-anilino), 11-Aun, AVA, Beta-hHyp(Bzl), Cha, Chg, Cmpi, Disc, Dpr(beta-Ala), GM, GBzA, B-Gpa, GVA(Cl), His, hSer, Ser(Bzl), Tic, hHyp, Hyp(Bzl), Inp, 2-Naphthylacetyl, (Nlys)Gly, OcHx, Pip, 4-phenylPro, 5-phenylPro, Pyr, Sar, Tle, Tiq, Atc, Igl, Hyp(O-2-Naphthyl), Hyp(O-Phenyl), 2-Aic, Idc, 1-Aic, Beta-homoSer(Bzl), Ser(O-2-Naphthyl), Ser(O-Phenyl), Ser(O-4-Cl-Phenyl), Ser(O-2-Cl-Phenyl), Thr(Bzl), Tic, Beta-homoThr(Bzl), Thr(O-2-Naphthyl), Thr(O-Phenyl), Thr(O-4-Cl-Phenyl) and Thr(O-2-Cl-Phenyl), Nle, Leu, Ile, Val and Beta-Ala.

49. A composition comprising a compound of any one of claims 1 , 20 and 39 in combination with a pharmaceutically acceptable carrier.

50. A method for altering a disorder or condition associated with the activity of a melanocortin receptor, comprising administering to a patient a therapeutically effective amount of the composition of claim 49 .

51. The method of claim 50 wherein the disorder or condition is an eating disorder.

52. The method of claim 51 wherein the eating disorder is cachexia.

53. The method of claim 51 wherein the eating disorder is obesity and associated impairment of energy homeostasis.

54. The method of claim 50 wherein the disorder or condition is sexual dysfunction.

55. The method of claim 54 wherein the sexual dysfunction is erectile dysfunction.

56. The method of claim 54 wherein the sexual dysfunction is female sexual dysfunction.