Synthesis and pharmacological properties of the N-terminal decapeptide of the vasoactive intestinal peptide (VIP).

The decapeptide derivative, L-histidyl-L-seryl-L-aspartyl-L-alanyl-L-valyl-L-phenylalanyl-L-threonyl-L-aspartyl-L-asparaginyl-L-tyrosine methyl ester, corresponding to the N-terminal sequence of both porcine and chicken VIP was synthesized in solution, by the stepwise strategy. Its pharmacological properties resemble those of VIP itself, but with a much lower potency, comparable to that of peptides with C-terminal sequences. The presence of two independent sequences carrying similar instructions was recognized in VIP.