Karnamicin, a complex of new antifungal antibiotics. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties

A complex of new antifungal antibiotics designated karnamicin was isolated from the cultured broth of Saccharothrix aerocolonigenes No. N806-4. Fifteen components have so far been isolated from the complex; the major component karnamicin B2 was identified by X-ray crystallography to be a novel molecule unrelated to known antibiotics. All components of karnamicin exhibited a rather broad spectrum of activity against fungi and yeasts with MICs ranging from 3.1 to 50 micrograms/ml.