Melanocortin receptor ligands

A compound according to formula (I):

• (R2R3)-A1-c (A2-A3-A4-A5-A6-A7-A8-A9)-A10-R1
• wherein:
• A1 is Acc, HN—(CH2)m—C(O), L- or D-amino acid or deleted;
• A2 is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Asp or Glu;
• A3 is Gly, Ala, β-Ala, Gaba, Aib, D-amino acid or deleted;
• A4 is His, 2-Pal, 3-Pal, 4-Pal, Taz, 2-Thi, 3-Thi or (X1, X2, X3, X4, X5) Phe;
• A5 is D-Phe, D-1-Nal, D-2-Nal, D-Trp, D-Bal, D-(X1, X2, X3, X4, X5) Phe, L-Phe or D-(Et) Tyr;
• A6 is Arg, hArg, Dab, Dap, Lys, Orn or HN—CH((CH2)n—N(R4R5))—C(O);
• A7 is Trp, 1-Nal, 2-Nal, Bal, Bip, D-Trp, D-1-Nal, D-2-Nal, D-Bal or D-Bip;
• A8 is Gly, D-Ala, Acc, Ala, β-Ala, Gaba, Apn, Ahx, Aha, HN—(CH2) s-C(O) or deleted;
• A9 is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Dab, Dap, Orn or Lys;
• A10 is Acc, HN—(CH2)t—C(O), L- or D-amino acid or deleted;
• R1 is —OH or —NH2;
• R2 and R3 is, independently for each occurrence, H, (C1-C30)alkyl, (C1-C30)heteroalkyl, (C1-C30)acyl, (C2-C30)alkenyl, (C2-C30)alkynyl, aryl(C1-C30)alkyl, aryl(C1-C30)acyl, substituted (C1-C30)alkyl, substituted (C1-C30)heteroalkyl, substituted (C1-C30)acyl, substituted (C2-C30)alkenyl, substituted (C2-C30)alkynyl, substituted aryl(C1-C30)alkyl or substituted aryl(C1-C30)acyl;
• R4 and R5 is, independently for each occurrence, H, (C1-C40)alkyl, (C1-C40)heteroalkyl, (C1-C40)acyl, (C2-C40)alkenyl, (C2-C40)alkynyl, aryl(C1-C40)alkyl, aryl(C1-C40)acyl, substituted (C1-C40)alkyl, substituted (C1-C40)heteroalkyl, substituted (C1-C40)acyl, substituted (C2-C40)alkenyl, substituted (C2-C40)alkynyl, substituted aryl(C1-C40)alkyl, substituted aryl(C1-C40)acyl, (C1-C40)alkylsulfonyl or —C(NH)—NH2;
• m is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;
• n is, independently for each occurrence, 1, 2, 3, 4 or 5;
• s is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;
• t is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;
• and
• X1, X2, X3, X4, and X5 each is, independently for each occurrence, H, F, Cl, Br, I, (C1-10)alkyl, substituted (C1-10)alkyl, (C2-10)alkenyl, substituted (C2-10)alkenyl, (C2-10)alkynyl, substituted (C2-10)alkynyl, aryl, substituted aryl, OH, NH2, NO2, or CN;
• provided that
• (I). when R4 is (C1-C40)acyl, aryl(C1-C40)acyl, substituted (C1-C40)acyl, substituted aryl(C1-C40)acyl, (C1-C40)alkylsulfonyl or —C(NH)—NH2, then R5 is H, (C1-C40)alkyl, (C1-C40)heteroalkyl, (C2-C40)alkenyl, (C2-C40)alkynyl, aryl(C1-C40)alkyl, substituted (C1-C40)alkyl, substituted (C1-C40)heteroalkyl, substituted (C2-C40)alkenyl, substituted (C2-C40)alkynyl or substituted aryl(C1-C40)alkyl;
• (II). when R2 is (C1-C30)acyl, aryl(C1-C30)acyl, substituted (C1-C30)acyl or substituted aryl(C1-C30)acyl, then R3 is H, (C1-C30)alkyl, (C1-C30)heteroalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, aryl(C1-C30)alkyl, substituted (C1-C30)alkyl, substituted (C1-C30)heteroalkyl, substituted (C2-C30)alkenyl, substituted (C2-C30)alkynyl or substituted aryl(C1-C30)alkyl;
• (III). either A3 or A8 or both must be present in said compound;
• (IV). when A2 is Cys, D-Cys, hCys, D-hCys, Pen or D-Pen, then A9 is Cys, D-Cys, hCys, D-hCys, Pen or D-Pen;
• (V). when A2 is Asp or Glu, then A9 is Dab, Dap, Orn or Lys;
• (VI). when A8 is Ala or Gly, then A1 is not Nle;
• and
• (VII). when A1 is deleted, then R2 and R3 cannot both be H;
• or a pharmaceutically acceptable salt thereof.