Ansamycin antibiotic

摘要

A new subspecies of Streptomyces nigellus Prokop, designated Streptomyces nigellus Prokop subsp. africanus Huang subsp. nov. ATCC 31496, when propagated under aerobic conditions in aqueous nutrient media, produces a mixture of antibiotics. One of these antibiotics is the known macrolide antibiotic cirramycin A; the ansamycin antibiotic is an analogue of protostreptovaricin and the structure has been established as 21-hydroxy, 25-demethyl, 25-methylthioprotostreptovaricin I.