Biosynthesis of fumonisin and aal derivatives by Alternaria and Fusarium in laboratory culture.

Cultures of Fusarium moniliforme and Alternaria alternata f. sp. lycopersici were grown in the laboratory and analyzed for various fumonisin derivatives. Analyses were made by continuous flow fast atom bombardment and ionspray mass spectrometry interfaced to microcapillary HPLC. Besides FB1, FB2 and FB3 derivatives, two isomers of the one-armed FB1 (protonated molecular ion at m/z 564) and two isomers of the one-armed FB2 (m/z 548) were found. Two different isolates of A. alternata when grown in culture yielded FB1, FB2 and FB3. One of them also yielded the one-armed FB1 which was identical to that metabolite found in Fusarium and naturally infected corn. FB1, FB2 and FB3 have been found in 2 different isolates of Alternaria alternata, both obtained from tomato.