Results
Title

Stable isotopic labelling-assisted untargeted metabolic profiling reveals novel conjugates of the mycotoxin deoxynivalenol in wheat.

Authors

Kluger, Bernhard; Bueschl, Christoph; Lemmens, Marc; Berthiller, Franz; Häubl, Georg; Jaunecker, Günther; Adam, Gerhard; Krska, Rudolf; Schuhmacher, Rainer

Abstract

An untargeted screening strategy for the detection of biotransformation products of xenobiotics using stable isotopic labelling (SIL) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) is reported. The organism of interest is treated with a mixture of labelled and non-labelled precursor and samples are analysed by LC-HRMS. Raw data are processed with the recently developed MetExtract software for the automated extraction of corresponding peak pairs. The SIL-assisted approach is exemplified by the metabolisation of the Fusarium mycotoxin deoxynivalenol (DON) in planta. Flowering ears were inoculated with 100 μg of a 1 1 ( v/ v) mixture of non-labelled and fully labelled DON. Subsequent sample preparation, LC-HRMS measurements and data processing revealed a total of 57 corresponding peak pairs, which originated from ten metabolites. Besides the known DON and DON-3-glucoside, which were confirmed by measurement of authentic standards, eight further DON-biotransformation products were found by the untargeted screening approach. Based on a mass deviation of less than ±5 ppm and MS/MS measurements, one of these products was annotated as DON-glutathione (GSH) conjugate, which is described here for the first time for wheat. Our data further suggest that two DON-GSH-related metabolites, the processing products DON- S-cysteine and DON- S-cysteinyl-glycine and five unknown DON conjugates were formed in planta. Future MS/MS measurements shall reveal the molecular structures of the detected conjugates in more detail.

Subjects

BIOTRANSFORMATION (Metabolism); XENOBIOTICS; STABLE isotopes; FUSARIUM; GLUTATHIONE; METABOLITES

Publication

Analytical & Bioanalytical Chemistry, 2013, Vol 405, Issue 15, p5031

ISSN

1618-2642

Publication type

Academic Journal

DOI

10.1007/s00216-012-6483-8