Studies on the mechanism of polyketide-derived biosynthesis of deoxyradicinin and related metabolites of Alternaria helianthi

Abstract

The polyketide biosynthetic origin of deoxyradicinin, deoxyradicinol and 3-epideoxyradicinol has been demonstrated by incorporation studies with ¹³C-labelled precursors and ¹³C n.m.r. spectroscopy. The ¹³C n.m.r., ²H n.m.r., and mass spectra of deoxyradicinin isolated from fungal cultures grown in the presence of [²H₃]sodium acetate indicated an uncommon condensation of two polyketide chains rather than a single hexaketide unit undergoing cyclization and ring-cleavage.