Thermal degradation of the Fusarium mycotoxin deoxynivalenol.
Deoxynivalenol (DON) is a toxic secondary metabolite produced by molds of the Fusarium genus, which are able to infect cereal crops in the field. Concerning its rate of occurrence and mean concentration, DON is one of the most important mycotoxins in cereal commodities. Its toxic effects range from causing diarrhea, vomiting, and gastro-intestinal inflammation to noncompetitive inhibition of the biosynthesis of proteins in eukaryotic cells. To study the stability of DON under food-processing conditions such as cooking or baking, we performed model heating experiments and screened the residue for degradation products. Heating of DON and 3-acetyldeoxynivalenol (3-AcDON), especially under alkaline conditions, gave a mixture of compounds, which were isolated and structurally elucidated by NMR and MS experiments. Three of these compounds were already known (norDON A, norDON B, and norDON C), while four were new and named 9-hydroxymethyl DON lactone, norDON D, norDON E, and norDON F. The significance of the DON degradation products was checked by analyzing commercially available food samples. norDON A, B, and C were detected in 29-66% of the samples in mean concentrations ranging from 3 to 15 microg/kg. Furthermore, cell culture experiments using IHKE cells showed that the compounds that were detected in food samples are less cytotoxic in the formazan dye cytotoxicity assay compared to DON. Whereas DON revealed a median effective concentration (EC50) at 1.1 micromol/L, all other compounds did not show any significant effect up to 100 micromol/L. These findings indicate that the degradation of DON under thermal treatment might reduce the toxicity of DON contaminated food.
Bretz
Michael
M
Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 45, 48149 Münster, Germany.
Beyer
Marita
M
Cramer
Benedikt
B
Knecht
Anja
A
Humpf
Hans-Ulrich
HU
D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D002523:Edible Grain / Q000737:chemistry*; D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling / Q000379:methods; D005670:Fusarium / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D006801:Humans; D007668:Kidney; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D014255:Trichothecenes / Q000737:chemistry* / Q000633:toxicity
D014255:Trichothecenes; C007262:deoxynivalenol