Bioconversion of possible T-2 toxin precursors by a mutant strain of Fusarium sporotrichioides NRRL 3299

Abstract

Liquid cultures of a mutant strain of Fusarium sporotrichioides NRRL 3299 that accumulates trichodiene rather than T-2 toxin converted tricho-9-ene-2α,3α,11α-triol, trichotriol (tricho-10-ene-2α,3α,9α-triol), tricho-10-ene-2α,3α,9β-triol, 3α-hydroxytrichothecene, and 3α-acetoxytrichothecene to T-2 toxin. Other possible oxygenated precursors of T-2 toxin, including trichodiol (tricho-10-ene-2α,9α-diol), trichothecene, 4α-hydroxytrichothecene, and 15-hydroxytrichothecene, were not metabolized. The results indicate that in the biosynthesis of T-2 toxin by F. sporotrichioides, (i) oxygenation at C-3 occurs prior to the second cyclization, (ii) this second cyclization involves two steps that may be nonenzymatic, and (iii) oxidation at C-3 precedes that at C-4 or C-15.