Metabolomic Analysis of the Secretome of Human Embryonic Stem Cells Following Methyl Parathion and Methyl Paraoxon Exposure. Phase 3. LC-MS-MS Structural Confirmation.

摘要

This technical report is the third of three reports from the U.S. Army Edgewood Chemical Biological Center (ECBC) In-House Laboratory Independent Research (ILIR) funded project Molecular Toxicology of TICs in Human Embryonic Stem Cells . One of the goals of the study was to identify metabolites from the secretome of human embryonic stem cells (hESC) exposed to the toxic industrial chemicals (TICs) methyl parathion (MP) and methyl paraoxon (MPO). The non- targeted liquid chromatography followed by mass spectrometry (LC-MS) approach used in the Phase I work (Sekowski et al., ECBC-TR-1177) revealed hundreds of human metabolites and multiple metabolic pathways altered as a result of exposure to both chemicals. This was followed by Phase II work (Madren-Whalley et al., ECBC-TR-1178) in which twenty metabolites were down-selected for further structural confirmation. The purpose of this Phase III study was to confirm the identity of the down-selected subset of putative metabolites by comparing them with commercially available standards using liquid chromatography followed by tandem mass spectrometry (LC-MS-MS). Commercially available standards were available for nine metabolites. Of these nine, the identity of five metabolites was confirmed in this work.