Microbial transformation of 6-nitrobenzo[a]pyrene.
The fungal metabolism of the potent mutagenic and carcinogenic nitropolycyclic aromatic hydrocarbon (nitro-PAH) 6-nitrobenzo[a]pyrene (6-NO2-BaP) was investigated. Cunninghamella elegans was incubated with 6-NO2-BaP for periods ranging between 1 and 7 d, and the metabolites formed were separated by high-performance liquid chromatography and identified by their UV-visible absorption, mass, and 1H nuclear magnetic resonance spectra. The results of our study indicate that C. elegans metabolized 6-NO2-BaP to glucoside and sulfate conjugates of 1- and 3-hydroxy 6-NO2-BaP and suggests that glycosylation and sulfation reactions may represent detoxification pathways in the fungal metabolism of nitro-PAHs. Experiments using [G3H]-6-NO2-BaP indicated that C. elegans metabolized 62% of 6-NO2-BaP within 168 h. Our data also indicated that the nitro group at the C-6 position of benzo[a]pyrene blocked metabolism at the regions peri to the nitro substituent (C-7, C-8 positions) and enhanced metabolism at the C-1 and C-3 positions. The ability of the fungus C. elegans to metabolize 6-NO2-BaP to biologically inactive compounds may have practical applications in the detoxification of nitro-PAH-contaminated wastes.
D001580:Benzopyrenes / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D005658:Fungi / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008658:Inactivation, Metabolic; D009682:Magnetic Resonance Spectroscopy; D013057:Spectrum Analysis; D013997:Time Factors
D001580:Benzopyrenes; C034699:6-nitrobenzo(a)pyrene