The Analogs of 8-D-Homoarginin-vasopressin with O-Substituted Phenylalanine in Position 2: Synthesis and Some Biological Properties

Abstract

Solid phase methodology on p-methylbenzhydrylamine resin was used for the synthesis of four analogs of vasopressin with the non coded amino acids, D-homoarginine (in position 8) and o-substituted L- or D-phenylalanine (in position 2). [L-Phe(o-Me)2,D-Har8]vasopressin (I), [D-Phe(o-Me)2,D-Har8]vasopressin (II), [L-Phe(o-Et)2,D-Har8]vasopressin (III) and [D-Phe(o-Et)2,D-Har8]vasopressin (IV) were synthesized. All analogs had very low antidiuretic activity. Analogs I and IV were low pressor inhibitors. All analogs were found to be the uterotonic inhibitors, the most potent on in vitro being [D-Phe(o-Et)2,D-Har8]vasopressin with a pA2 = 8.4.