Ferensimycins A and B. Two polyether antibiotics. Taxonomy, fermentation, isolation, characterization and structural studies.

Ferensimycin A* (I), C34H59O10Na, mp 133 approximately 135 degrees C, and ferensimycin B** (II), C35H61O10Na, mp 143 approximately 145 degrees C, were isolated as their sodium salts from the fermentation broth of Streptomyces sp. No. 5057, a strain similar to Streptomyces myxogenes Shomura et al. The physicochemical data of I and II showed that they are both closely related congeners of lysocellin (III). Ferensimycins A and B exhibit activity against Gram-positive bacteria and are effective in the treatment of coccidiosis of fowl.