Pleofungins, novel inositol phosphorylceramide synthase inhibitors, from Phoma sp. SANK 13899 II. Structural elucidation

Abstract

Pleofungins (formerly called F-15078) A, B, C and D, novel depsipeptide antifungal antibiotics, were found in a mycelium extract of the producing fungus, Phoma sp. SANK 13899. The structures of pleofungins A, B, C and D were elucidated mainly by various NMR studies. The absolute configurations of the amino acids and N-methyl amino acids of pleofungin A constituents in the hydrolysate were determined by the application of advanced Marfey's method in combination with gas chromatography/mass spectrometry analysis of their silylation products with N-methyl-N-(tert-butylsilyl)-trifluoroacetamide. Two α-hydroxy acid constituents, α- hydroxyisocaproic acid and α-hydroxyisovaleric acid, were isolated from the hydrolysate and their stereochemistries were determined by their specific rotations. © Japan Antibiotics Research Association.