title: Spectrophotometric study on the oxidation of rutin by horseradish peroxidase and characteristics of the oxidized products.
abstract: Rutin (3',4',5,7-tetrahydroxyflavone-3-rutinoside) was oxidized by a horseradish peroxidase-H2O2 system to an ascorbate-reducible product which had an absorption maximum at about 290 nm and a shoulder at about 440 nm at pH 4. At pH 7.8, ascorbate-reducible compounds and sodium hydrosulfite-reducible and -nonreducible compounds were formed by the oxidation. The ascorbate-reducible compounds consisted of at least two components, the absorption bands of which were at 460-480 nm and about 620 nm. The sodium hydrosulfite-reducible compounds also consisted of two components, and one of the components which had an absorption maximum at about 480 nm seems to be formed from the ascorbate-reducible component of an absorption maximum at the blue region by a nonenzymatic reaction. A mixture of oxidized products of rutin formed by tert-butyl hydroperoxide-dependent oxidation was similar to that formed by the enzymatic reaction. It is discussed that the 3'- and 4'-OH groups of rutin were oxidized by the horseradish peroxidase-H2O2 system and that the oxidized product which could be reduced by ascorbate is an o-quinone derivative.
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism*; D010545:Peroxides / Q000494:pharmacology; D012431:Rutin / Q000378:metabolism*; D013053:Spectrophotometry; D020122:tert-Butylhydroperoxide
chemical_list: D010545:Peroxides; D012431:Rutin; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010544:Peroxidases; D001205:Ascorbic Acid