Analysis of glutathione-adducts of (+/-)-anti-7,8 dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro-benzoapyrene by liquid chromatography/tandem mass spectrometry

摘要

Oxidative stress is one of the major consequences of exposure to environmental pollutants such as cigarette smoke. The major component of the environmental pollutants are polycyclic aromatic hydrocarbons (PAH), such as benzo[a]pyrene (B[a]P). It is metabolized to 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro-B[a]P by combination of CYPs and epoxide hydrolase. Further B[a]P-7,8-diolepoxide formed either DNA adducts with DNA bases or undergoes detoxification by forming the glutathione adducts. The GSH adducts of B[a]P diolepoxide were further metabolized in the extracellular milieu to a cysteinylglycine adducts. These adducts further hydrolyzed to cysteine conjugate by amino dipeptidase enzyme. The cysteinyl conjugates are acetylated by N-acetyl transferase enzyme. Our current study is focused on the analysis of GSH and cysteinylglycine adducts of (+/-)-anti-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro-B[a] Pin human bronchoalveolar H358 cells, after exposure to B[a]P-7,8-dihydrodiol, by LC-MS/MS. The product ion spectrum of standard of B[a]P-7,8-diolepoxide-GSH adduct was compared with MS/MS spectra of B[a]P-7,8-diolepoxide-GSH adducts in H358 treated cells with B[a]P-7,8-dihydrodiol to confirm the formation of B[a]PDE-GSH adducts Supported by NIH grants 1R01CA130038 and 5P30ES013508.