Biosynthetic studies with 13C : The antifungal antibiotic ilicicolin H

Abstract

The results of feeding experiments conducted with 13C-labeled acetates, 15N-labeled phenyl-alanine, and 14C-labeled phenylalanine in fermentations of Cylindrocladium ilicicola MFC 870 are consistent with the polyketide pathway to ilicicolin H, the principal metabolite. The origin of the 5-(4-hydroxyphenyl-α-pyridone) unit in ilicicolin H is via an intermediate tetramic acid derivative, analogous to the biosynthesis of the same unit in tenellin. The two reduced carbocyclic rings of ilicicolin H are derived through cyclization of a linear polyketide precursor.