Fatty acid esters of fumonisins: production on cornmeal media and occurrence in naturally infected maize kernels

Fumonisin derivatives obtained by esterification of fumonisin B1 (FB1) with palmitic, oleic and linoleic fatty acids have been recently described, but never reported in raw maize so far. In this study, the presence of oleoyl-EFB1 (EFB1OA) and linoleoyl-EFB1 (EFB1LA) in raw maize is reported by means of a suitable LC-ESI-MS/MS method. In addition, the production of EFB1 derivatives by three Fusarium verticillioides strains is described on malt extract–based media and on corn meal–based growth media. EFB1OA and EFB1LA were produced by all considered strains in corn meal medium, with EFB1LA > EFB1OA. On the contrary, EFB1OA and EFB1LA were never observed in Fusarium cultures grown on a malt extract medium, suggesting that the esterification of FB1 can occur only in a complex matrix such as maize.