Primary arylamine oxidation by a flavinhydroperoxide. A study of the basis for the substrate specificity of the flavoprotein monooxygenase.
4a-Hydroperoxy-5-ethyl-3,8,10-trimethylisoalloxazine (FlEtOOH) was prepared as a chemical model for the flavin-containing monooxygenase enzyme of mammalian liver. FlEtOOH was found to oxidize a series of para-substituted primary arylamines to the corresponding arylnitroso compound. The rates of arylamine oxidation were found to correlate with the Hammett substituent constant, sigma, as well as with amine basicity. These results suggest that amine nucleophilicity should be an important determinant of flavin monooxygenase reactivity toward primary arylamines; nevertheless, the enzyme demonstrates considerable substrate preference based on other factors.
D000588:Amines; D000818:Animals; D005415:Flavins; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D008954:Models, Biological; D010084:Oxidation-Reduction; D010545:Peroxides; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D000588:Amines; D005415:Flavins; D010545:Peroxides; C043035:4 alpha-hydroperoxy-5-ethyl-3,8,10-trimethylisoalloxazine; D006899:Mixed Function Oxygenases