Studies on fungal metabolites. Part 2. Carbon-13 nuclear magnetic resonance biosynthetic studies on pentaketide metabolites of Aspergillus melleus: 3-(1,2-epoxypropyl)-5,6-dihydro-5-hydroxy-6-methylpyran-2-one and mellein

Abstract

The ¹³C n.m.r. spectra and incorporations of ¹³C-labelled precursors into pyrone and dihydroisocoumarin pentaketide metabolites from the culture liquors of Aspergillus melleus are reported. Detection of a two-bond ¹³C–¹³C coupling in a metabolite enriched from [1,2-¹³C₂]acetate provides proof for an intramolecular rearrangement occurring during biosynthesis.