Synthesis, biological activity and receptor binding affinity of six new antagonists of [8-L-arginine]vasopressin

Abstract

Six analogues of d(CH2)5AVP, a vasopressin inhibitor, modified in positions 1, 2, 4, and 9 were synthesized and the effect of the modifications on the inhibitory potency was followed. Buly and lipophilic substitutions in position 1 in combination with Abu substitution in position 4 led to a slight decrease of antivasopressor potency and a strong decrease of the antiuterotonic potency. Alkylation of any type of carboxamide group at positions 4 and 9 strongly reduced the biological potency in all the tests.