Reductive metabolism of 4-nitrobiphenyl by rat liver fraction.
The metabolites of 4-nitrobiphenyl (4-NBP) were studied using S-9 under anaerobic conditions. Ten metabolites were isolated and tentatively identified by high-performance liquid chromatography/atmospheric pressure chemical ionization/mass spectrometry (HPLC/APCI/MS), which is a novel efficient technqiue for analyses of metabolites. HPLC retention times and UV spectra have been also used for the confirmation. Among them, 4-aminobiphenyl (4-ABP, 79% of total metabolites) and hydroxylaminobiphenyls were found to be the major metabolites, and 4-acetylaminobiphenyl (4-AABP), N-hydroxy-4-acetylaminobiphenyl (4-AABP-N-OH), x-OH-4-nitrobiphenyl (4-NBP-x-OH), biphenylene and N-formyl-4-aminobiphenyl (N-formyl-4-ABP) were the minor metabolites. Based on the metabolities identified, different metabolic pathways of 4-NBP in rat liver, including N-hydroxylation, N-acetylation, N-formylation, de-nitro-group biotransformation and ring hydroxylation were proposed to elucidate the mechanisms of toxification and detoxification. In addition, experimental conditions such as incubation time and S-9 amounts were optimized.
Ning
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Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, P. R. China.
Xiaobai
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X
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008099:Liver / Q000378:metabolism*; D013058:Mass Spectrometry; D009596:Nitrophenols / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D015842:Serine Proteinase Inhibitors / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
D009596:Nitrophenols; D015842:Serine Proteinase Inhibitors; C024719:4-nitrophenyl