Study about fluostatins: efficient preparation of fluostatin A and discovery of fluostatin derivatives from Streptomyces sp. TA-3391.

Fluostatins are a class of compounds having four unique ring systems. They were originally isolated as dipeptidyl peptidase III (DPP3) inhibitors, and various derivatives and activities have been reported. In this study, fluostatin A, which is difficult to prepare by fermentative production, was effectively prepared by the transformation of fluostatin B. A new derivative, fluostatin Y, and a new naturally occurring derivative, fluostatin B2, were obtained, and their structures were determined. Furthermore, the bioactivity, DPP3 inhibitory activity, and antibacterial and cytotoxic activities were examined.