Liquid-phase synthesis of naturally occurring peptides, II. Syntheses of three mast cell degranulating tetradecapeptide amides from wasp venoms.

The liquid-phase synthesis of three tetradecapeptideamides corresponding to the amino acid sequences of the wasp venoms mastoparan, mastoparan X, and Polistes mastoparan is described. The 4-(aminomethyl)-3-nitrobenzoyl-amino-poly(ethylene glycol) monomethyl ether was employed as the soluble support, and the completed peptideamides were cleaved from it by photolysis at 350 nm. After removal of protecting groups, the free peptide amides were purified by column chromatography on Sephadex G-25, and found to have expected elemental and amino acid composition; a satisfactory recovery of tryptophan from synthetic Mastoparan X and Polistes Mastoparan suggests that no extensive destruction of its indole ring occurred during the photolysis. The peptideamides so obtained are active in degranulating the rat peritoneal mast cells.