TY - JOUR
T1 - The reaction of flavonoid metabolites with peroxynitrite
AU - Pollard, Susan E.
AU - Kuhnle, Gunter G. C.
AU - Vauzour, David
AU - Vafeiadou, Katerina
AU - Tzounis, Xenofon
AU - Whiteman, Matthew
AU - Rice-Evans, Catherine
AU - Spencer, Jeremy P. E.
PY - 2006/12/1
Y1 - 2006/12/1
N2 - 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.
AB - 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.
KW - Flavonoids
KW - Nitrates
KW - Oxidation-Reduction
KW - Peroxynitrous Acid
U2 - 10.1016/j.bbrc.2006.09.131
DO - 10.1016/j.bbrc.2006.09.131
M3 - Article
C2 - 17045238
SN - 0006-291X
VL - 350
SP - 960
EP - 968
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 4
ER -