Adrenocorticotropin. 47. Synthesis and biological activity of adrenocorticotropic peptides modified at the tryptophan position.

Three biologically active peptides, [9-beta-(1-naphthyl)alanine]-ACTH-(1-19), [9-Ni-formyltryptophanl-ACTH-1(1-19), and (8-lysine,9-phenylalaninel-ACTH-1(1-9), have been synthesized by the solid-phase method. All of the synthetic peptides showed diminished biological activity compared to ACTH-(1-19). It was also shown that the steroidogenic and lipolytic activities of ACTH-(1-19) were not inhibited by [8-lysine,.-phenylalanine]-ACTH-(1-19).