Title: Potent orally active inhibitors of angiotensin-converting enzyme (ACE).
Abstract: 1-[3-Mercaptoalkanoyl] pyroglutamic acids and 1-[3-mercaptoalkanoyl]-4-hetero (oxa, thia and aza) pyroglutamic acids were prepared and their inhibitory activities against angiotensin-converting enzyme (ACE) were examined. (2S)-1-[(2S)-3-Mercapto-2-methylpropanoyl] pyroglutamic acid 2 was found to be the most potent orally active inhibitor of ACE of rabbit lung among the derivatives synthesized in the present study and appeared to have great potential for use as an oral antihypertensive agent.