Description
An antagonist of MC1R (Ki = 40 nM in COS-1 cells expressing human receptors); selective for MC1R over MC3R, MC4R, and MC5R (Kis = 470, 1,340, and 2,400 nM, respectively); inhibits α-MSH-induced cAMP accumulation and melanosome dispersion in melanocytes (IC50s = 2.5 and 11 nM, respectively)