TY - JOUR A1 - Mekonnen, Tessema Fenta A1 - Panne, Ulrich A1 - Koch, Matthias T1 - Prediction of biotransformation products of the fungicide fluopyram by electrochemistry coupled online to liquid chromatography-mass spectrometry and comparison with in vitro microsomal assays N2 - Biotransformation processes of fluopyram (FLP), a new succinate dehydrogenase inhibitor (SDHI) fungicide, were investigated by electrochemistry (EC) coupled online to liquid chromatography (LC) and electrospray mass spectrometry (ESI-MS). Oxidative phase I metabolite production was achieved using an electrochemical flow-through cell equipped with a boron doped diamond (BDD) electrode. Structural elucidation and prediction of oxidative metabolism pathways were assured by retention time, isotopic patterns, fragmentation, and accurate mass measurements using EC/LC/MS, LC-MS/MS, and/or high resolution mass spectrometry (HRMS). The results obtained by EC were compared with conventional in vitro studies by incubating FLP with rat and human liver microsomes (RLM, HLM). Known phase I metabolites of FLP (benzamide, benzoic acid, 7-hydroxyl, 8-hydroxyl, 7,8-dihydroxyl FLP, lactam FLP, pyridyl acetic acid, and Z/E-olefin FLP) were successfully simulated by EC/LC/MS. New metabolites including an imide, hydroxyl lactam, and 7-hydroxyl pyridyl acetic acid oxidative metabolites were predicted for the first time in our study using EC/LC/MS and liver microsomes. We found oxidation by dechlorination to be one of the major metabolism mechanisms of FLP. Thus, our results revealed that EC/LC/MS-based metabolic elucidation was more advantageous on time and cost of analysis and enabled matrix-free detection with valuable information about the mechanisms and intermediates of metabolism processes. KW - Metabolism KW - EC/LC/MS KW - Electrochemical oxidation KW - Biotransformation KW - SDHI-fungicide PY - 2018 UR - https://link.springer.com/article/10.1007%2Fs00216-018-0933-x#citeas U6 - https://doi.org/10.1007/s00216-018-0933-x SN - 1618-2650 SN - 1618-2642 VL - 410 IS - 10 SP - 2607 EP - 2617 PB - Springer CY - Heidelberg AN - OPUS4-44491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -