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

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