Synthesis of angiotensin II antagonists with variations in position 5

Six angiotensin II antagonists containing cyclohexylglycine (Chg) or cyclopentylglycine (Cpg) in position 5 were synthesized by stepwise elongation in solution, using the pentafluorophenyl ester method. The influence of substitution on the inhibitory properties of the analogues was studied in four different bioassays. [Sar1,Chg5,Lac8]AII proved to be the most potent antagonist with low intrinsic activity in both the in vitro and in vivo tests.