title: Conversion of Congo red and 2-azoxyfluorene to mutagens following in vitro reduction by whole-cell rat cecal bacteria.
abstract: Congo red, an azo dye derived from benzidine, and 2-azoxyfluorene, a derivative of 2-aminofluorene, were reduced during overnight incubation with a suspension of rat intestinal bacteria. High performance liquid chromatography and ultraviolet spectral analysis verified the presence of benzidine in extracts of the Congo red incubations and 2-aminofluorene in extracts of the 2-azoxyfluorene incubations. Extracts of the Congo red incubations were mutagenic toward Salmonella typhimurium TA1538 in the presence of a post-mitochondrial activating system, but Congo red was not mutagenic without this reductive pretreatment. Thus, the utility of the Ames test in screening for potential mutagens may be expanded by a reductive pretreatment utilizing cecal bacteria.
mesh_terms: D000818:Animals; D001711:Biotransformation; D002432:Cecum / Q000382:microbiology*; D003224:Congo Red / Q000378:metabolism* / Q000633:toxicity; D005449:Fluorenes / Q000378:metabolism* / Q000633:toxicity; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens; D009154:Mutation; D010084:Oxidation-Reduction; D051381:Rats; D011916:Rats, Inbred F344; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D005449:Fluorenes; D009153:Mutagens; C037537:2-azoxyfluorene; D003224:Congo Red