Calbistrins, novel antifungal agents produced by Penicillium restrictum. I. Production, taxonomy of the producing organism and biological activity.

Abstract

A novel antibiotic complex, named the calbistrins, has been discovered in the culture broth of a soil fungus. The producing organism, designated AB 1875C-28, was identified as a strain of Penicillium restrictum. Calbistrin A, the most potent of the 4-membered complex, has MICs of 0.78 micrograms/ml against Candida albicans. Only poor activity is observed against non-candida yeasts, filamentous fungi and bacteria.