Fusarium strains were isolated from rotten banana fruit imported into Hungary from some African and some Neotropical countries. The strains were identified using morphological features, 2-benzoxazolinone tolerance, translation elongation factor (EF-1α) sequences and inter simple sequence repeat (ISSR) analysis. All strains from Africa proved to be F. verticillioides whereas the strains from the Neotropics are Fusarium musae. According to the PCR proof and the fumonisin toxin measurement F. musae strains cannot produce any fumonisins (FB1–4).
Fumonisins were produced by six strains of Fusarium moniliforme and Fusarium proliferatum on inoculated rice culture. For study of fumonisins of the B series (B1, B2, B3, and B4) a quick and efficient two-step reversed-phase OPLC method was developed in which the first step serves for cleaning of the samples. Measurements were performed with the automatic OPLC instrument. Results showed that one isolate of F. moniliforme and one of F. proliferatum produced all the fumonisins investigated – the other isolates produced no fumonisins. This work is the first report of the separation of all the fumonisins of the B series by use of a planar layer liquid chromatographic technique.
Fumonisins were extracted from a rice culture which had been inoculated with
isolated from maize stalk. The culture extracts were analysed by a hyphenated technique: reversed-phase high-performance liquid chromatography/electrospray ionization ion-trap mass spectrometry (RP-HPLC/ESI-IT MS
). Besides already known fumonisins, a new type of fumonisin series (PHFB4OSA belonging to the formerly described FBX)-containing four new compounds-was detected. At these compounds, one of the OH groups attached to the fumonisin backbone was esterified by carboxylic acid (oxalylsuccinic acid, OSA) other than tricarballylic acid (TCA). The masses of the protonated molecules and of the characteristic product ions and the characteristic neutral mass losses from the protonated molecules suggested their structure. The relative quantities of the new minor compounds were expressed as percentages of FB1 toxin.