Zearalenone-16-O-glucoside: a new masked mycotoxin

J Agric Food Chem. 2014 Feb 5;62(5):1181-9. doi: 10.1021/jf405627d. Epub 2014 Jan 21.

Abstract

This paper reports the identification of a barley UDP-glucosyltransferase, HvUGT14077, which is able to convert the estrogenic Fusarium mycotoxin zearalenone into a near-equimolar mixture of the known masked mycotoxin zearalenone-14-O-β-glucoside and a new glucose conjugate, zearalenone-16-O-β-glucoside. Biocatalytical production using engineered yeast expressing the HvUGT14077 gene allowed structural elucidation of this compound. The purified zearalenone-16-O-β-glucoside was used as an analytical calibrant in zearalenone metabolization experiments. This study confirmed the formation of this new masked mycotoxin in barley seedlings as well as in wheat and Brachypodium distachyon cell suspension cultures. In barley roots, up to 18-fold higher levels of zearalenone-16-O-β-glucoside compared to the known zearalenone-14-O-β-glucoside were found. Incubation of zearalenone-16-O-β-glucoside with human fecal slurry showed that this conjugate can also be hydrolyzed rapidly by intestinal bacteria, converting the glucoside back to the parental mycotoxin. Consequently, it should be considered as an additional masked form of zearalenone with potential relevance for food safety.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bacteria / metabolism
  • Brachypodium / chemistry
  • Brachypodium / metabolism*
  • Female
  • Food Contamination
  • Glucosides / chemistry
  • Glucosides / metabolism*
  • Glucosyltransferases / genetics
  • Glucosyltransferases / metabolism
  • Hordeum / chemistry
  • Hordeum / enzymology
  • Hordeum / genetics
  • Hordeum / metabolism*
  • Humans
  • Intestinal Mucosa / metabolism
  • Intestines / microbiology
  • Male
  • Microbiota
  • Mycotoxins / chemistry
  • Mycotoxins / metabolism*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Triticum / chemistry
  • Triticum / metabolism*
  • Zearalenone / chemistry*
  • Zearalenone / metabolism*

Substances

  • Glucosides
  • Mycotoxins
  • Plant Proteins
  • Zearalenone
  • Glucosyltransferases