Oxidative modification of quercetin by hemeproteins.
The ability of a number of hemeproteins to oxidize the flavonoid quercetin has been shown. It was found that quercetin undergoes chemical modification in the presence of cytochrome c, myoglobin, and hemoglobin but not cytochrome b(5). In the range of investigated proteins the most effective oxidant appears to be cytochrome c. Chromatographic analysis of the reaction mixture revealed a number of quercetin oxidation products. The main oxidation product was purified and characterized by means of LC-MS and NMR analyses. It has a dimeric structure similar to the product of quercetin oxidation by horseradish peroxidase and is formed during radical-driven reactions. Our results indicate that a number of hemeproteins can react and modify biologically active flavonoids. However, these reactions might also lead to the generation of active species with deleterious consequences for the cellular macromolecules.
Institute of Bioorganic Chemistry, Academy of Sciences of Belarus, Kuprevicha st., 5/2, Minsk 220141, Belarus.
Egor M
EM
Cherviakovsky
Dmitry A
DA
Bolibrukh
Alexander V
AV
Baranovsky
Tamara M
TM
Vlasova
Vladimir P
VP
Kurchenko
Andrey A
AA
Gilep
Sergey A
SA
Usanov
D000818:Animals; D002853:Chromatography, Liquid; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism; D006420:Hemeproteins / Q000737:chemistry* / Q000378:metabolism*; D006736:Horses; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D016877:Oxidants / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D011794:Quercetin / Q000737:chemistry* / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
D005419:Flavonoids; D006420:Hemeproteins; D016877:Oxidants; D045304:Cytochromes c; D011794:Quercetin