Metabolism of 7-nitrobenz[a]anthracene by intestinal microflora.
Pure cultures of anaerobic intestinal bacteria and mixed fecal microflora from human, rat, mouse, and pig were screened for the ability to metabolize 7-nitrobenz[a]anthracene (7-NO2BA). Based on analysis by high-performance liquid chromatography (HPLC) and by ultraviolet (UV), mass, and nuclear magnetic resonance (NMR) spectral techniques, the compounds were identified as 7-aminobenz[a]anthracene (7-NH2BA) and benz[a]anthracene 7,12-dione (dione). Identification of 7-NH2BA as a metabolite of 7-NO2BA indicates that the anaerobic intestinal bacteria are capable of reducing 7-NO2BA to potentially bioactive intermediates. The reductive capacities of the mixed intestinal microflora were generally greater than those of pure cultures. Thus, metabolism of 7-NO2BA in the intestinal tract may be underestimated if pure cultures are used as the sole method for evaluating the potential hazard.
Morehead
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National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079.
Franklin
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Fu
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Evans
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Heinze
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Cerniglia
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CE
D000818:Animals; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001551:Benz(a)Anthracenes / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003016:Clostridium perfringens / Q000378:metabolism; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D010084:Oxidation-Reduction; D051381:Rats; D011916:Rats, Inbred F344; D013552:Swine
D001551:Benz(a)Anthracenes; C038954:7-nitrobenzanthracene