Synthesis and pharmacological activity of angiotensin converting enzyme inhibitors: N-(mercaptoacyl)-4-substituted-(S)-prolines.

The synthesis of a series of N-(mercaptoacyl)-4-substituted-(S)-prolines (2 and 3) is described. These compounds were evaluated in vitro for inhibition of angiotensin-converting enzyme (ACE), and selected compounds were evaluated in vivo for ACE inhibition. The most potent compounds in vitro are 108, 109, 111, 114, and 116, having relative potencies of 1.0, 1.0, 1.3, 1.1, and 2.6 as compared to the potency of captopril. The most potent compounds in vivo intravenously are 108, 111, 114, 116, 117, and 97.