Fatty acid esters of fumonisins: first evidence of their presence in maize.

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.