Absolute structural determination of stevastelin B.

Stevastelin B, obtained from a culture of a Penicillium sp. NK374186, is a novel depsipeptide containing three amino acids and 3, 5-dihydroxy-2, 4-dimethylstearic acid. The stereochemistry of the three amino acids was determined by HPLC analysis, and the relative configuration of the 3, 5-dihydroxy-2, 4-dimethylstearic acid was elucidated by chemical conversion and NMR analysis. The absolute stereochemistry of Stevastelin B was determined by synthetic methods.