Deamination of fumonisin B-1 and biological assessment of reaction producttoxicity

Fumonisin B-1, a potent mycotoxin found in grain, has been resistant to deg radation and detoxification by a variety of methods, including milling, fer mentation, ammoniation, and ozonation. The primary amine of this compound c ontributes significantly to its toxicity; therefore, the major aim of this research was to remove this moiety via diazotization. In this study, fumoni sin B-1 was deaminated in aqueous solution under conditions of acidic pH an d low temperature (pH 1.0 and 5 degreesC) with the addition of NaNO2. The c oncentration of fumonisin B-1 in the solution was analyzed by HPLC using o- phthaldialdehyde to derivatize the primary amine. Progress of the reaction was monitored as a loss of the derivatized peak as observed by HPLC with fl uorescence detection. TLC analysis showed the disappearance of fumonisin B- 1 following diazotization. Further, TLC displayed at least four reaction pr oducts that were not primary amines. Matrix-assisted laser desorption/ioniz ation mass spectrometry coupled with time-of-flight analysis of the diazoti zation products also showed a diminished amount of authentic fumonisin B-1 and allowed identification of a product formed by the replacement of the pr imary amine with a hydroxyl group. The adult Hydra attenuata bioassay indic ated a marked decrease in the toxicity of the products in comparison to par ent fumonisin B-1. Optimization of this reaction could result in a rapid an d practical method for the reclamation of fumonisin B-1-contaminated feeds.