A121--an antifungal compound from Streptomyces species.

A non-polyene antifungal antibiotic, A121, produced by an unidentified strain of Streptomyces species was isolated and purified to homogeneity. This antibiotic was found to be active against a number of filamentous fungi including some plant and human pathogens. On the basis of its infrared spectrum, proton magnetic resonance, mass spectra, and some chemical derivatives, a plausible chemical constitution of this antibiotic is proposed. Its antibiotic activity apparently requires the presence of an alpha-ketol system in the molecule.