TY - JOUR A1 - Drzymala, Sarah A1 - Riedel, Juliane A1 - Köppen, Robert A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Preparation of 13C-labelled cis-zearalenone and its application as internal standard in stable isotope dilution analysis N2 - Pure U-[13C18]-labelled cis-zearalenone (cis-ZEA) has been prepared and characterised as internal standard (ISTD) for a reliable quantification of cis-ZEA in contaminated food and feed products. The cis-isomer of the naturally trans-configurated Fusarium mycotoxin zearalenone is often neglected. However, isomerisation easily occurs by exposure of ZEA to (UV-)light. Thus, the applicability of the new cis-ZEA ISTD was demonstrated in a long-term isomerisation study comparing naturally trans-ZEA-contaminated edible oil with spiked edible oil. To estimate the benefits of the newly prepared cis-ZEA ISTD, various approaches to quantify cis-ZEA by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) were compared. As a result, a significant bias was revealed if no appropriate cis-ZEA standards are used. Furthermore, the new ISTD was applied to the analysis of 15 edible oils by stable isotope dilution analysis in combination with HPLC-electrospray ionisation-MS/MS. One of the maize germ oils showed the presence of cis-ZEA above LOD (>0.3 µg/kg), whereas two out of 15 maize germ oils were found to be contaminated with trans-ZEA (range 17.0-31.0 µg/kg). KW - ZEA KW - Zearalenone KW - Isomerisation KW - Occurrence KW - Edible oil KW - SIDA KW - HPLC-MS/MS KW - Quantification KW - LC-MS/MS PY - 2014 U6 - https://doi.org/10.3920/WMJ2013.1610 SN - 1875-0710 SN - 1875-0796 VL - 7 IS - 1 SP - 45 EP - 52 PB - Wageningen Academic Publishers CY - Wageningen AN - OPUS4-30126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Binder, J. A1 - Brodehl, Antje A1 - Penkert, M. A1 - Rosowski, M. A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Estrogenicity of novel phase I and phase II metabolites of zearalenone and cis-zearalenone N2 - Zearalenone and its cis-isomer, cis-zearalenone, are nonsteroidal mycotoxins that elicit an estrogenic response upon binding to the estrogen receptor. This study compares the estrogenicity of eleven congeners including novel metabolites as 15-OH-zearalenone, zearalenone-14-sulfate, α-cis-zearalenol and β-cis-zearalenol using the E-Screen assay. Overall, a change in the configuration from trans to cis retains significant estrogenic activity. In contrast, alterations of the aromatic moiety including hydroxylation and sulfation showed a markedly decreased estrogenicity when compared to zearalenone. KW - Zearalenone KW - Mycotoxin KW - MCF-7 KW - E-screen assay KW - Estrogenicity KW - Isomerization PY - 2015 U6 - https://doi.org/10.1016/j.toxicon.2015.08.027 SN - 0041-0101 SN - 1879-3150 VL - 105 SP - 10 EP - 12 PB - Elsevier CY - Oxford [u.a.] AN - OPUS4-34167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -