title: Genotoxicity-related chemistry of human metabolites of benzo[ghi]perylene (B[ghi]P) investigated using electro-optical arrays and DNA/microsome biocolloid reactors with LC-MS/MS.
abstract: There is limited and sometimes contradictory information about the genotoxicity of the polycyclic aromatic hydrocarbon benzo[ghi]perylene (B[ghi]P). Using recently developed metabolic toxicity screening arrays and a biocolloid reactor-LC-MS/MS approach, both featuring films of DNA and human metabolic enzymes, we demonstrated the relatively low reactivity of metabolically activated B[ghi]P toward DNA. Electro-optical toxicity screening arrays showed that B[ghi]P metabolites damage DNA at a 3-fold lower rate than benzo[a]pyrene (B[a]P), whose metabolites have a strong and well-understood propensity for DNA damage. Metabolic studies using magnetic bead biocolloid reactors coated with microsomal enzymes in 96-well plates showed that cyt P450s 1A1 and 1B1 provide high activity for B[ghi]P and B[a]P conversion. Consistent with published results, the major metabolism of B[ghi]P involved oxidations at 3,4 and 11,12 positions, leading to the formation of B[ghi]P 3,4-oxide and B[ghi]P 3,4,11,12-bisoxide. B[ghi]P 3,4-oxide was synthesized and reacted with deoxyadenosine at N6 and N7 positions and with deoxyguanosine at the N2 position. B[ghi]P 3,4-oxide is hydrolytically unstable and transforms into the 3,4-diol or converts to 3- or 4-hydroxy B[ghi]P. LC-MS/MS of reaction products from the magnetic biocolloid reactor particles coated with DNA and human enzymes revealed for the first time that a major DNA adduct results from the reaction between B[ghi]P 3,4,11,12-bisoxide and deoxyguanosine. Results also demonstrated 5-fold lower formation rates of the major DNA adduct for B[ghi]P metabolites compared to B[a]P. Overall, results from both the electro-optical array and biocolloid reactor-LC-MS/MS consistently suggest a lower human genotoxicity profile of B[ghi]P than B[a]P.
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: Shenmin
authors.initials: S
authors.lastname: Pan
authors.forename: Dandan
authors.initials: D
authors.lastname: Li
authors.forename: Linlin
authors.initials: L
authors.lastname: Zhao
authors.forename: John B
authors.initials: JB
authors.lastname: Schenkman
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D001564:Benzo(a)pyrene / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D065633:Cytochrome P-450 CYP1B1; D004247:DNA / Q000032:analysis* / Q000378:metabolism; D018736:DNA Adducts / Q000032:analysis; D004249:DNA Damage / Q000187:drug effects; D006801:Humans; D008280:Magnetics; D046228:Microarray Analysis; D011095:Polyethylenes / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000295:instrumentation
chemical_list: D018736:DNA Adducts; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D001564:Benzo(a)pyrene; D004247:DNA; D001189:Aryl Hydrocarbon Hydroxylases; C585496:CYP1B1 protein, human; D019363:Cytochrome P-450 CYP1A1; D065633:Cytochrome P-450 CYP1B1