Phenacein-an angiotensin-converting enzyme inhibitor produced by a streptomycete: I. taxonomy, fermentation and biological properties

Abstract

Phenacein, 3,6-dihydroxy-l-phenazinecarboxylic acid, was a specific angiotensin-converting enzyme (ACE) inhibitor isolated from a member of the Streptomyces tanashiensis-zaomyceticus group. Phenacein acted as a pure competitive inhibitor with a Ki of 0.58, μm. ACE inhibition could be reversed by Zn+ +, but not by Co+ +, Ca+ +, or Mg+ +; therefore, phenacein may chelate the active site zinc of ACE. However, other zinc-containing enzymes were not inhibited at high phenacein concentrations. Phenacein exhibited weak activity against Gram-positive bacteria, but was not active against Candida sp. or Gram-negative organisms. © 1984, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.