Chaetochromin, a Bis (naphthodihydropyran-4-one) Mycotoxin from Chaetomium thielavioideum : Application of ¹³C-¹H Long-rang Coupling to the Structure Elucidation

Abstract

Details of the separation of the metabolites (I-V) of Chaetomium thielavioideum are presented. The structure of a new mycotoxin named chaetochromin was studied by physical method (ultraviolet, infrared, ¹H- and ¹³C-nuclear magnetic resonance (NMR), and mass spectrum) and it was identified as the bis (naphthodihydropyran-4-one (II). The assignment of the ¹³C-NMR signals was largely achieved with the aid of the two-and three-bond spin-spin couplings between ¹³C and ¹H.