title: 4-{(2R)-[3-Aminopropionylamido]-3-(2,4-dichlorophenyl)propionyl}-1-{2-[(2-thienyl)ethylaminomethyl]phenyl}piperazine as a potent and selective melanocortin-4 receptor antagonist--design, synthesis, and characterization.
abstract: Recent studies have demonstrated that melanocortin-4 receptor (MC4R) antagonists can prevent weight loss in tumor-bearing mice, which indicates clinical usage for the treatment of cachexia. In our efforts to develop potent and selective antagonists of the human MC4R, we designed piperazinebenzylamines bearing a 2,4-dichlorophenylalanine, by utilizing information derived from structure--activity relationships of MC4R agonists and mutagenesis results of the MC4R and peptide ligands. On the basis of known MC4R agonists such 6, we successfully synthesized potent MC4R antagonists exemplified by 10, which possesses a K(i) value of 1.8 nM in binding affinity. 10 does not stimulate cAMP release in HEK 293 cells expressing the human MC4 receptor at 10 microM concentration. It was demonstrated by Schild analysis that 10 was a competitive functional antagonist with a pA(2) value of 7.9 in the inhibition of alpha-MSH-stimulated cAMP accumulation. 10 also penetrated into the brain when dosed intravenously in rats.
authors.affiliation: Neurocrine Biosciences, Inc. 12790 El Camino Real, San Diego, CA 92130, USA. cchen@neurocrine.com
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Joseph
authors.initials: J
authors.lastname: Pontillo
authors.forename: Beth A
authors.initials: BA
authors.lastname: Fleck
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Gao
authors.forename: Jenny
authors.initials: J
authors.lastname: Wen
authors.forename: Joe A
authors.initials: JA
authors.lastname: Tran
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Tucci
authors.forename: Dragan
authors.initials: D
authors.lastname: Marinkovic
authors.forename: Alan C
authors.initials: AC
authors.lastname: Foster
authors.forename: John
authors.initials: J
authors.lastname: Saunders
mesh_terms: D000818:Animals; D002100:Cachexia / Q000188:drug therapy*; D000242:Cyclic AMP / Q000096:biosynthesis; D015195:Drug Design; D006801:Humans; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000737:chemistry; D051379:Mice; D008958:Models, Molecular; D016296:Mutagenesis; D010879:Piperazines / Q000138:chemical synthesis* / Q000494:pharmacology; D044105:Receptor, Melanocortin, Type 4 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D013876:Thiophenes / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: C496210:4-((3-aminopropionylamido)-3-(2,4-dichlorophenyl)propionyl)-1-(2-((2-thienyl)ethylaminomethyl)phenyl)piperazine; C470072:MC4R protein, human; D010879:Piperazines; D044105:Receptor, Melanocortin, Type 4; D013876:Thiophenes; D009074:Melanocyte-Stimulating Hormones; D000242:Cyclic AMP