A new antifungal antibiotic, cystargin: Fermentation, isolation, and characterization.

Abstract

A new sulfur-containing peptide antifungal antibiotic, cystargin, was isolated from the fermentation broth of a new species of genus Kitasatosporia, designated as Kitasatosporia cystarginea. On acid hydrolysis, cystargin (C60H77N19O17S6) gave equimolar glycine, proline, aspartic acid and arginine. By performic acid oxidation, cysteic acid was detected after hydrolysis. It showed a growth inhibitory activity against various phytopathogenic fungi and inhibition of beta-1,3-glucan synthetase from Saccharomyces cerevisiae.