Studies on Peptides. LXXVI. Synthesis of Kassinin, a New Frog Skin Peptide

Abstract

Kassinin, a dodecapeptide amide isolated by Erspamer et al. from the skin of Kassina senegalensis, was synthesized by deprotection of Z (OMe)-Asp (OBzl)-Val-Pro-Lys (Z)-Ser-Asp (OBzl)-Gln-Phe-Val-Gly-Leu-Met (O)-NH₂ with methanesulphonic acid, followed by reduction of the Met (O) residue to Met with 2-mercaptoethanol. The contractile activity of synthetic kassinin in isolated guinea-pig ileum was 0.4 of that of synthetic substance P.