Design and pharmacology of peptoids and peptide–peptoid hybrids based on the melanocortin agonists core tetrapeptide sequence

A series of N-substituted glycine oligomers (peptoids) and peptide–peptoid hybrids were synthesized based on the Ac-His-Phe-Arg-Trp-NH2 tetrapeptide template. The compounds were pharmacologically characterized at the mouse melanocortin receptors (MC1R, MC3R–MC5R) for agonist activity.