Melanocortin receptor ligands modified with hydantoin

1. A compound of formula (III)

wherein

X is selected from the group consisting of CH 2 —S—S—CH 2 —, —C(CH 3 ) 2 —S—S—CH 2 —, —CH 2 —S—S—C(CH 3 ) 2 —, —C(CH 3 ) 2 —S—S—C(CH 3 ) 2 —, (CH 2 ) 2 —S—S—CH 2 —, —CH 2 —S—S—(CH 2 ) 2 , —(CH 2 ) 2 —S—S—(CH 2 ) 2 —, —C(CH 3 ) 2 —S—S—(CH 2 ) 2 —, —(CH 2 ) 2 —S—S—C(CH 3 ) 2 —, —(CH 2 ) r C(O)—NR 8 —(CH 2 ) r — and —(CH 2 ) r —NR 8 —C(O)—(CH 2 ) t —;

R 1 and R 5 each is, independently, H, (C 1 -C 10 )alkyl or substituted (C 1 -C 10 )alkyl;

R 2 and R 3 each is, independently, H, (C 1 -C 10 )alkyl, (C 1 -C 10 )heteroalkyl, aryl(C 1 -C 5 )alkyl, substituted (C 1 -C 10 )alkyl, substituted (C 1 -C 10 )heteroalkyl or substituted aryl(C 1 -C 5 )alkyl or R 2 and R 3 may be joined together to form a ring;

R 4 is —OH or —NH 2 ;

R 6 and R 7 each is, independently, H, (C 1 -C 10 )alkyl or substituted (C 1 -C 10 )alkyl;

A 1 is an L- or D-amino acid or deleted;

A 2 is His, 2-Pal, 3-Pal, 4-Pal, Phe, Taz, 2-Thi or 3-Thi;

A 3 is D-Bal, D-1-Nal, D-2-Nal, or D-Phe;

A 4 is Arg, hArg, Dab, Dap, Lys or Orn;

A 5 is Bal, 1-Nal, 2-Nal, Phe or Trp;

r is, independently for each occurrence thereof, 1, 2, 3, 4 or 5; and

t is, independently for each occurrence thereof, 1 or 2; or

a pharmaceutically acceptable salt thereof.

2. A compound selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

3. A pharmaceutical composition comprising a therapeutically effective amount of a compound according to claim 1 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent.

4. A pharmaceutical composition comprising a therapeutically effective amount of a compound according to claim 2 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent.

5. A method of treating a disease or medical condition in a subject in need of such treatment, comprising administering to said subject a compound according to claim 1 , wherein said disease or condition is selected from the group consisting of:

general inflammation, inflammatory bowel disease, brain inflammation, sepsis and septic shock;

rheumatoid arthritis, gouty arthritis and multiple sclerosis;

a metabolic disease or medical condition accompanied by weight loss, anorexia, bulimia, AIDS wasting, cachexia, cancer cachexia and wasting in frail elderly;

skin cancer and cancer cachexia;

endometriosis, uterine bleeding, sexual dysfunction, erectile dysfunction and decreased sexual response in females;

organ transplant rejection, ischemia and reperfusion injury, wounding and spinal cord injury, and weight loss due to a medical procedure selected from the group consisting of chemotherapy, radiation therapy, temporary or permanent immobilization and dialysis;

hemorrhagic shock, cardiogenic shock, hypovolemic shock, cardiovascular disorders and cardiac cachexia;

acute respiratory distress syndrome, pulmonary fibrosis, chronic obstructive pulmonary disease and asthma;

enhanced immune tolerance;

allergies;

psoriasis, skin pigmentation depletion, acne and keloid formation;

anxiety, depression, memory dysfunction and neuropathic pain; and

renal cachexia and natriuresis.

6. A method of treating a disease or medical condition in a subject in need of such treatment, comprising administering to said subject a compound according to claim 1 , wherein said disease or condition is selected from the group consisting of:

a metabolic disease or medical condition accompanied by weight gain, obesity, feeding disorders and Prader-Willi Syndrome;

diabetes, diabetalogical related conditions and complications of diabetes such as retinopathy.

7. The method according to claim 6 , wherein obesity is treated.

8. The method according to claim 6 , wherein body weight is decreased.

9. The method according to claim 6 , wherein diabetes is treated.

10. The method according to claim 6 , wherein complications of diabetes are treated.

11. A method of modulating ovarian weight, placental development, prolactin secretion, FSH secretion, intrauterine fetal growth, parturition, spermatogenesis, thyroxin release, aldosterone synthesis and release, body temperature, blood pressure, heart rate, vascular tone, brain blood flow, blood glucose levels, sebum secretion, pheromone secretion, motivation, learning and behavior, pain perception, neuroprotection, nerve growth, bone metabolism, bone formation and bone development in a subject, comprising administering to said subject a compound according to claim 1 .

12. A method of inhibiting alcohol consumption, reducing alcohol consumption, treating alcoholism, or treating alcohol abuse in a subject, comprising administering to said subject a therapeutically effective amount of a compound according to claim 1 , or a pharmaceutically acceptable salt thereof.