Discovery of 1-amino-4-phenylcyclohexane-1-carboxylic acid and its influence on agonist selectivity between human melanocortin-4 and -1 receptors in linear pentapeptides

Linear pentapeptides (Penta-cis-Apc-DPhe-Arg-Trp-Gly-NH2) containing 1-amino-4-phenylcyclohexane-1-carboxylic acid (cis-Apc) and substituted Apc are potent hMC4R agonists and they are inactive or weakly active in hMC1R, hMC3R, and hMC5R agonist assays. This study, together with our earlier report on 5-BrAtc, demonstrated the importance of replacing His6 with phenyl-containing rigid templates in achieving good hMC4R agonist potency and selectivity against hMC1R in linear pentapeptides.

Graphical abstractA design and synthesis of cis-Apc as new histidine surrogate and its incorporation into linear pentapeptides (Penta-cis-Apc-DPhe-Arg-Trp-Gly-NH2) and related analogs leading to potent and selective hMC4R agonists are reported.Figure optionsDownload full-size imageDownload as PowerPoint slide