title: Cleavage of zearalenone by Trichosporon mycotoxinivorans to a novel nonestrogenic metabolite.
abstract: Zearalenone (ZON) is a potent estrogenic mycotoxin produced by several Fusarium species most frequently on maize and therefore can be found in food and animal feed. Since animal production performance is negatively affected by the presence of ZON, its detoxification in contaminated plant material or by-products of bioethanol production would be advantageous. Microbial biotransformation into nontoxic metabolites is one promising approach. In this study the main transformation product of ZON formed by the yeast Trichosporon mycotoxinivorans was identified and characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and LC-diode array detector (DAD) analysis. The metabolite, named ZOM-1, was purified, and its molecular formula, C(18)H(24)O(7), was established by time of flight MS (TOF MS) from the ions observed at m/z 351.1445 [M-H](-) and at m/z 375.1416 [M+Na](+). Employing nuclear magnetic resonance (NMR) spectroscopy, the novel ZON metabolite was finally identified as (5S)-5-({2,4-dihydroxy-6-[(1E)-5-hydroxypent-1-en-1-yl]benzoyl}oxy)hexanoic acid. The structure of ZOM-1 is characterized by an opening of the macrocyclic ring of ZON at the ketone group at C6'. ZOM-1 did not show estrogenic activity in a sensitive yeast bioassay, even at a concentration 1,000-fold higher than that of ZON and did not interact with the human estrogen receptor in an in vitro competitive binding assay.
authors.affiliation: Department for Agrobiotechnology (IFA Tulln), Christian Doppler Laboratory for Mycotoxin Research, University of Natural Resources and Applied Life Sciences Vienna, Konrad Lorenz Str. 20, 3430 Tulln, Austria. elisavet.vekiru@boku.ac.at
authors.forename: Elisavet
authors.initials: E
authors.lastname: Vekiru
authors.forename: Christian
authors.initials: C
authors.lastname: Hametner
authors.forename: Rudolf
authors.initials: R
authors.lastname: Mitterbauer
authors.forename: Justyna
authors.initials: J
authors.lastname: Rechthaler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Gerd
authors.initials: G
authors.lastname: Schatzmayr
authors.forename: Rudolf
authors.initials: R
authors.lastname: Krska
authors.forename: Rainer
authors.initials: R
authors.lastname: Schuhmacher
mesh_terms: D001711:Biotransformation; D002853:Chromatography, Liquid; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013256:Steroids / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014250:Trichosporon / Q000378:metabolism*; D015025:Zearalenone / Q000037:antagonists & inhibitors* / Q000378:metabolism*
chemical_list: D013256:Steroids; D015025:Zearalenone