Cinatrins, a novel family of phospholipase A sub(2) inhibitors, I. Taxonomy and fermentation of the producing culture; Isolation and structures of cinatrins

Cinatrins A, B, C sub(1), C sub(2) and C sub(3), a family of phospholipase A sub(2) inhibitors were isolated from the fermentation broth of Circinotrichum falcatisporum) RF-641. They were found to be novel spiro- gamma -dilactones and gamma -lactones derived from 1,2,3,5-tetra or 1,2,3(or 1,2,4)-trihydroxypentadecane-1,2,3-tricarboxylic acids. Structures were elucidated by MS and NMR studies and chemical transformations. The structure of cinatrin C sub(3) was confirmed by X-ray crystallographic analysis, and its absolute configuration was determined by comparison of the CD spectra with related compounds.