The structure of the antifungal antibiotic versicolin.

The established metabolites of Aspergillus versicolor include numerous xanthones and anthraquinones, and a substituted imide1}. Recently Dhar and Bose2) reported the isolation of a new antifungal antibiotic, named versicolin, from the culture nitrate of a strain of A. versicolor. Low yielding cultures of A. versicolor could be regenerated by mutagenic treatment3*. Versicolin was notable because of its high specific activity against several human dermatophytes, particularly Trichophyton rubrum which causes 90% of the skin infections in eastern India2>4). It was essentially inactive against gram-positive and gram-negative bacteria, yeasts and a variety of other fungi2>4). Versicolin was subsequently assigned5) a