R. Vleggaar

Trichothecene mycotoxins from Fusarium sulphureum

Abstract Four mycotoxins isolated from moulded maize cultures of Fusarium sulphureum have been characterized as 3α,4β,15-triacetoxy-12,13-epoxytrichothec-9-ene, 4β,15-diacetoxy-3α-hydroxy-12,13-epoxytrichothec-9-ene, 15-acetoxy-3α,4β-dihydroxy-12,13-epoxytrichothec-9-ene and 4β-acetoxy-3α,15-dihydroxy-12,13-epoxytrichothec-9-ene.

Structure elucidation and absolute configuration of the tyledosides, bufadienolide glycosides from Tylecodon grandiflorus

The isolation and characterization of six related bufadienolide glycosides, tyledosides A, B, C, D, F, and G from Tylecodon grandiflorus(Burm. F) Toelken are reported. The structure elucidation of these metabolites is based on a detailed study of their highfield 1H and 13C n.m.r. spectra. Extensive use was made of two-dimensional homonuclear and heteronuclear correlation experiments in the assignment of the n.m.r. spectra. The results obtained upon chemical derivatization of tyledosides A, C, and D are in agreement with the assigned structures.