title: HT-2 toxin 4-glucuronide as new T-2 toxin metabolite: enzymatic synthesis, analysis, and species specific formation of T-2 and HT-2 toxin glucuronides by rat, mouse, pig, and human liver microsomes.
abstract: Glucuronides of the mycotoxin T-2 toxin and its phase I metabolite HT-2 toxin are important phase II metabolites under in vivo and in vitro conditions. Since standard substances are essential for the direct quantitation of these glucuronides, a method for the enzymatic synthesis of T-2 and HT-2 toxin glucuronides employing liver microsomes was optimized. Structure elucidation by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry revealed that besides T-2 toxin glucuronide and HT-2 toxin 3-glucuronide also the newly identified isomer HT-2 toxin 4-glucuronide was formed. Glucuronidation of T-2 and HT-2 toxin in liver microsomes of rat, mouse, pig, and human was compared and metabolites were analyzed directly by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). A distinct, species specific pattern of glucuronidation of T-2 and HT-2 toxin was observed with interesting interindividual differences. Until recently, glucuronides have frequently been analyzed indirectly by quantitation of the aglycone after enzymatic cleavage of the glucuronides by β-glucuronidase. Therefore, the hydrolysis efficiencies of T-2 and HT-2 toxin glucuronides using β-glucuronidases from Helix pomatia, bovine liver, and Escherichia coli were compared.
authors.affiliation: Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstraße 45, D-48149 Münster, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Welsch
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Humpf
mesh_terms: D000818:Animals; D005966:Glucuronidase / Q000378:metabolism; D020719:Glucuronides / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D013045:Species Specificity; D013552:Swine; D013605:T-2 Toxin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism*; D014316:Tritium
chemical_list: D020719:Glucuronides; D014316:Tritium; D014453:Glucuronosyltransferase; D005966:Glucuronidase; D013605:T-2 Toxin; C012351:HT-2 toxin