title: In vitro metabolic N-oxidation of azo compounds. I. Evidence for formation of azo N-oxides (azoxy compounds).
abstract: Certain azo compounds and their N-oxides have been prepared and characterized by spectroscopic methods. A HPLC method for the quantification of azo-N-oxide metabolites of those azo compounds is described. The enzymic N-oxidation of azo compounds in vitro has been demonstrated as a general metabolic pathway. In the case of the mixed aryl-alkyl azo compound, only one N-oxide was detected. The identity of N-oxide metabolites has been confirmed by CG/MS. Azo-N-oxidase activity was detected principally in the liver, but also in lung, heart and kidney whole organ homogenates. Studies using subcellular fractions showed that azo N-oxidase activity resides mainly in the hepatic microsomal fraction. The amount of N-oxide formed under optimised incubation conditions by hamster microsomal preparations is greatest with omega, omega'-azoxytoluene (AXT) and least with azoxybenzene (AXB); while omega-(phenylazoxy)toluene (PAXT) is intermediate.
authors.affiliation: Chelsea Department of Pharmacy, Kings College London, UK.
authors.forename: M H
authors.initials: MH
authors.lastname: Koh
authors.forename: J W
authors.initials: JW
authors.lastname: Gorrod
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006224:Cricetinae; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006168:Guinea Pigs; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D013058:Mass Spectrometry; D008647:Mesocricetus; D051379:Mice; D010084:Oxidation-Reduction; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014050:Toluene / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D001547:Benzaldehydes; D014050:Toluene; C009850:azobenzene; C032175:benzaldehyde