Production of fumonisin B and C analogues by several fusarium species

Six strains of Fusarium verticillioides, two of F. oxysporum, one strain of F. proliferatum, and a strain of an unidentified species were cultured on maize patties and rice and evaluated for their ability to simultaneously produce fumonisin B (FB) and C (FC) series analogues. Fumonisins were quantified by LC-MS-MS using positive ion electrospray ionization. FC 1 provided characteristic fragment ions at m/z 690, 672, 654, 532, 514, and 338 corresponding to sequential loss of H 2O and tricarboxylic acid moieties from the alkyl backbone, while FC 3 and FC 4 provided equivalent product ions 16 and 32 amu lower than the corresponding FC 1 fragments, respectively. All isolates cultured on maize produced FC 4. All isolates except for that of F. proliferatum also produced FC 1, and three of the six strains of F. verticillioides produced FC 3. All isolates except those of F. oxysporum produced detectable amounts of FB 1, FB 2, and FB 3. Isolates that produced fumonisin B analogues produced at least 10 fold more of the B series analogues than they did of the C series analogues. The results confirm that at least some strains of F. oxysporum produce FC, but not FB, fumonisin analogues and also suggest that the genetics and physiological regulation of fumonisin production may be more complicated than previously envisaged since some strains of F. verticillioides and F. proliferatum as well as the strain of the unidentified species can simultaneously produce both FB and FC analogues. © 2005 American Chemical Society.