Trichothecene Biosynthesis in Fusarium sporotrichioides: Origin of the Oxygen Atoms of T-2 Toxin.

Mass spectral analysis of T-2 toxin formed during the growth of Fusarium sporotrichioides (ATCC 24043) in the presence of H(2)O showed incorporation of up to three O atoms per toxin molecule. The carbonyl oxygens of the acetates at C-4 and C-15 and of the isovalerate at C-8 were derived from H(2)O. Toxin formed in the presence of O molecular oxygen incorporated up to six O atoms per toxin molecule. The overall incorporation was 78 and 92% of toxin molecules labeled for H(2)O and O(2) labeled samples, respectively. The oxygens of position 1, the 12,13-epoxide, and the hydroxyl groups at C-3, C-4, C-8, and C-15 were all derived from molecular oxygen.