Heat-induced isomers of acetylated derivatives of deoxynivalenol and nivalenol

Abstract

As a part of a study on the heat stability of deoxynivalenol (DON) and nivalenol (NIV), the decomposition patterns of both compounds were determined by ELISA using a monoclonal antibody which recognizes the partially acetylated derivatives of DON and NIV (3, 15-diacetyl-DON and 3, 4, 15-triacetyl-NIV, respectively). In that investigation it was found that heat-induced derivatives of the toxins have a stronger cross-reactivity with the antibody. Considering the nature of the antibody, it was speculated that a structural change due to the rearrangement of the A-ring in the trichothecenes probably occurred. To corroborate this hypothesis. DON and NIV were heated in acetic anhydride to determine which compounds are formed during acetylation. Two new compounds were isolated from the reaction mixture: 3, 8, 15-triacetoxy-12, 13-epoxytrichothec-8-en-7-one (TAisoDON) and 3, 4, 8, 15-tetraacetoxy-12, 13-epoxytrichothec-8-en-7-one (TeAisoNIV), indicating that during heating at least part of the decrease in DON and NIV level is due to isomerization.