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Third-party-funded project

Title:
Fumonisins and their degradation products in food: Studies on the occurrence, stereochemistry, importance and mode of action.

Project management at the University of Würzburg:

Participating scientists:

Abstract:
Research activities in the field of mycotoxins include studies of the structure, occurrence, biosynthesis, metabolism and mode of action of fumonisins, a recently discovered new class of mycotoxins, predominantly found on yellow corn. Based on the on-line coupling of high-performance liquid chromatography and electrospray-ionization tandem mass spectrometry (HPLC-ESI-MS/MS) sensitive and highly selective methods for the detection of fumonisins and hydrolyzed fumonisins in food were developed. Of importance are also reaction products, e.g. N-carboxymethyl-fumonisins, which are formed during food manufacturing processes. During our studies on the mode of action of fumonisins, we showed for the first time that hydrolyzed fumonisins HFBx are not only inhibitors of the ceramide synthase but also substrates of the enzyme being converted to N-acyl-fumonisins in-vitro and in-vivo. The toxicity of the N-acyl-metabolites was evaluated using HT29 cells and the “brine-shrimp”-bioassay. The new metabolites were more toxic than FB1 or HFB1 and did not induce apoptosis.
For the determination of the absolute configuration of fumonisins circular dichroism spectroscopy was used. Based on the exciton-chirality method a sensitive and reliable procedure for the stereochemical assignment was developed. With this method, the stereochemistry of FB1 was determined to be 2S, 3S, 5R and that of FB3 to be 2S, 3S. The TCA-side chains of fumonisins are R-configured.

Key words:
    Fumonisins
    Mycotoxins
    Analysis
    Degradation products
    Metabolism
    Absolute configuration
    Mode of action
    Stereochemistry

Projekt period: from 08.1996 to 12.2002

Funding institution:
DFG ,Granting date: 1.07.1996

Publications:

Links:
Research area