title: A new approach to evaluating the extent of Michael adduct formation to PAH quinones: tetramethylammonium hydroxide (TMAH) thermochemolysis with GC/MS.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that are converted to cytotoxic and carcinogenic metabolites, quinones, by detoxifying enzyme systems in animals. PAH metabolites such as the quinones can form Michael adducts with biological macromolecules containing reactive nucleophiles, making detection of exposure to PAHs difficult using conventional techniques. A technique has been developed for detecting exposure to PAHs. Tetramethylammonium hydroxide (TMAH) thermochemolysis coupled with GC/MS is proposed as an assay method for PAH quinones that have formed Michael adducts with biological molecules. Three PAH quinones (1,4-naphthoquinone, 1,2-naphthoquinone, and 1,4-anthraquinone) and 1,4-benzoquinone were reacted with cysteine, and the TMAH thermochemolysis method was used to assay for both thiol and amine adduction between the quinones and the cysteine. Additional studies with 1,4-naphthoquinone adducts to glutathione and bovine serum albumin showed the same thiol and amine TMAH thermochemolysis products with larger peptides as was observed with cysteine adducts. The TMAH GC/MS method clearly shows great promise for detecting PAH quinones, produced by enzymatic conversion of PAHs in biological systems, that have been converted to respective Michael adducts.
authors: Department of Chemistry, The Ohio State University, Columbus, Ohio, 43210, USA.
authors: Mary K
authors: MK
authors: Briggs
authors: Emmanuel
authors: E
authors: Desavis
authors: Paula A
authors: PA
authors: Mazzer
authors: R B
authors: RB
authors: Sunoj
authors: Susan A
authors: SA
authors: Hatcher
authors: Christopher M
authors: CM
authors: Hadad
authors: Patrick G
authors: PG
authors: Hatcher
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000737:chemistry / Q000378:metabolism; D016227:Benzoquinones / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D005069:Evaluation Studies as Topic; D005602:France; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D016227:Benzoquinones; D009285:Naphthoquinones; D011084:Polycyclic Aromatic Hydrocarbons; D000644:Quaternary Ammonium Compounds; D012710:Serum Albumin, Bovine; C004532:quinone; C416442:1,4-anthraquinone; C040756:1,2-naphthoquinone; D005978:Glutathione; C027917:tetramethylammonium; D003545:Cysteine; C035342:1,4-naphthoquinone