New antifungal cycloheximide epimers produced by sp. YG7.

A couple of new cycloheximide epimers, 13(α)-acetoxy-anhydroisoheximide () and 13(β)-acetoxy-anhydroisoheximide (), together with six known compounds (38), were obtained from the cultures of Streptomyces sp. YG7. The structures were elucidated based on a comprehensive spectroscopic data analysis including 1D and 2D NMR, as well as HRESIMS, and by comparison with the literature.