A one-electron oxidation of carcinogenic nonaminoazo dye Sudan I by horseradish peroxidase.
OBJECTIVE
The aim of the study was to examine oxidation of carcinogenic Sudan I by peroxidase and characterize the structure of its two major peroxidasemediated metabolites. Another target of the study was to evaluate a mechanism of this oxidation.


METHODS
Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with ultraviolet (UV) and visible (VIS) detection was employed for the separation of Sudan I metabolites formed by peroxidase. UV/ VIS-, and mass- spectroscopy as well as nuclear magnetic resonance (NMR) were used to characterize structures of two major Sudan I metabolites.


RESULTS
Peroxidase oxidizes Sudan I by a one electron oxidation to eight products. Two major Sudan I metabolites were isolated by TLC on silica gel and HPLC and structurally characterized. The major product formed during the Sudan I oxidation by peroxidase is Sudan I metabolite M2, which corresponds to a Sudan I dimer molecule. The second major metabolite (M1) is the product of secondary, enzyme independent reactions, being formed from the Sudan I dimer that lost the benzenediazonium moiety.


CONCLUSIONS
The data are the first report on structural characterization of Sudan I metabolites formed by its oxidation with peroxidase.
Semanska
Marcela
M
Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic.
Dracinsky
Martin
M
Martinek
Vaclav
V
Hudecek
Jiri
J
Hodek
Petr
P
Frei
Eva
E
Stiborova
Marie
M
D002273:Carcinogens / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004583:Electrons; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009284:Naphthols / Q000737:chemistry*; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
D002273:Carcinogens; D009284:Naphthols; C024336:1-phenylazo-2-naphthol; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase