Discovery, isolation, and structure elucidation of dretamycin.

The Candida albicans fitness test is a whole cell screening platform that utilizes a mixed-pool of C. albicans mutants, each of which carries a heterozygous deletion of a particular gene. In the presence of an antifungal inhibitor, a subset of these mutants exhibits a growth phenotype of hypersensitivity or hyposensitivity. Collectively these mutants reflect aspects of the mechanism of action of the compound in question. In the course of screening natural products a culture of Streptomyces sp. MS-1-4 was discovered to produce a compound, dretamycin, which yielded a fitness profile exhibiting significant hypersensitivity of the DRE2 heterozygote and hyposensitivity of the DIP5 heterozygote. Herein we report the production, isolation, and structure elucidation of dretamycin.