Biotransformation of 1-nitropyrene to 1-aminopyrene and N-formyl-1-aminopyrene by the human intestinal microbiota.
The nitropolycyclic aromatic hydrocarbon 1-nitropyrene (1-NP) is an environmental pollutant, a potent bacterial and mammalian mutagen, and a carcinogen. The metabolism of 1-NP by the human intestinal microbiota was studied using a semicontinuous culture system that simulates the colonic lumen. [3H]-1-Nitropyrene was metabolized by the intestinal microbiota to 1-aminopyrene (1-AP) and N-formyl-1-aminopyrene (FAP) as determined by high-performance liquid chromatography (HPLC) and mass spectrometry. Twenty-four hours after the addition of [3H]-1-NP, the formylated compound and 1-AP accounted for 20 and 80% of the total metabolism, respectively. This percentage increased to 66% for FAP after 24 h following 10 d of chronic exposure to unlabeled 1-NP, suggesting metabolic adaptation to 1-NP by the microbiota. Both 1-AP and FAP have been shown to be nonmutagenic towards Salmonella typhimurium TA98, which indicates that the intestinal microflora may potentially detoxify 1-NP.
D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008658:Inactivation, Metabolic; D007422:Intestines / Q000382:microbiology*; D013058:Mass Spectrometry; D009152:Mutagenicity Tests; D010084:Oxidation-Reduction; D011721:Pyrenes / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000235:genetics
D011721:Pyrenes; C049354:N-formyl-1-aminopyrene; C004482:1-aminopyrene; C032668:1-nitropyrene