New renin inhibitors--stability and activity determination. Part II.

A series of new six pseudodipeptic potential renin inhibitors were synthesized. Enzymatic stability for all compounds (1-6) in homogenates (liver, kidney, lung) and body fluids (serum, gastric, intestinal juice) and alpha-chymotrypsin was determined. Compounds 4 was stable, compound 5 was unstable and compounds 1, 2, 3, 6 were partly unstable. Inhibitory activity of the compounds was measured in vitro by HPLC determination of lowering concentration of substrate (angiotensinogen) in the presence of renin and the potential renin inhibitor (compounds 1-6). Compound 4, 5, 6 showed inhibitory activity (0.9 x 10(-6), 1.3 x 10(-8), 2.2 x 10(-6) M, respectively). Other compounds showed no inhibitory activity up to 10(-5) M.