Studies on Peptides. CXVIII. Synthesis of a Hybrid Growth Hormone Releasing Factor (GRF)-PHI Heptacosapeptide Amide

Abstract

A hybrid heptacosapeptide amide, consisting of growth hormone releasing factor (GRF) tetradecapeptide (1-14) and PHI tridecapeptide (15-27), was synthesized by a fragment condensation procedure, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid. The synthetic peptide exhibited in vivo GRF activity (ca. 1/10 of that of GRF-44-NH₂), but lacked the blood pressure-decreasing activity of the parent PHI.