Ascosteroside, a new antifungal agent from Ascotricha amphitricha .1. Taxonomy, fermentation and biological activities

Ascosteroside, a novel antifungal compound, was isolated from the culture broth of Ascotricha amphitricha. This compound is an alpha-linked glycoside of a lanostane type triterpenoid. It is active against yeasts such as Candida albicans and Saccharomyces cerevisiae and against filamentous fungi but shows no activity against bacteria. It is not toxic to mammalian cells at concentrations up to 150 mu M. In a mouse model, the compound afforded protection comparable to that of ketoconazole.