K-13, a novel inhibitor of angiotensin I converting enzyme produced by Micromonospora halophytica subsp. exilisia. II. Structure determination

The structure of K-13, a potent inhibitor of angiotensin I converting enzyme (ACE), was determined to be a cyclic dipeptide composed of tyrosine and an unusual diamino dicarboxylic acid, isodityrosine, by spectral and chemical studies of K-13 and its derivatives.