The reaction of flavonoid metabolites with peroxynitrite

Susan E. Pollard, Gunter G. C. Kuhnle, David Vauzour, Katerina Vafeiadou, Xenofon Tzounis, Matthew Whiteman, Catherine Rice-Evans, Jeremy P. E. Spencer

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89 Citations (Scopus)


There is much interest in the bioactivity of in vivo flavonoid metabolites. We report for the first time the hierarchy of reactivity of flavonoid metabolites with peroxynitrite and characterise novel reaction products. O-Methylation of the B-ring catechol containing flavonoids epicatechin and quercetin, and O-glucuronidation of all flavonoids reduced their reactivity with peroxynitrite. The reaction of the flavanones hesperetin and naringenin and their glucuronides resulted in the formation of multiple mono-nitrated and nitrosated products. In contrast, the catechol-containing flavonoids epicatechin and quercetin yielded oxidation products which when trapped with glutathione led to the production of glutathionyl-conjugates. However, the O-methylated metabolites of epicatechin yielded both mono- and di-nitrated products and nitrosated metabolites. The 3'-O-methyl metabolite of quercetin also yielded a nitrosated species, although its counterpart 4'-O-methyl quercetin yielded only oxidation products. Such products may represent novel metabolic products in vivo and may also express cellular activity.
Original languageEnglish
Pages (from-to)960-968
Number of pages9
JournalBiochemical and Biophysical Research Communications
Issue number4
Publication statusPublished - 2006

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