The Production of Hydroxyl and Semiquinone Free Radicals During the Autoxidation of Redox Active Flavonoids

摘要: Catechols and other polyphenolic compounds have been shown to autoxidize generate reactive oxygen species. A few examples of such include epinephrine, 6-hydroxydopamine,2 pyrogallol.3 We previously reported that members a class polyphenolics, the flavonoids (Figure 1), behave in similar manner. In particular four flavonoids, myricetin (3,5,7,3’,4’,5’-hexahydroxyflavone), quercetagetin (3,5,6,7,3’,4’-hexahydroxyflavone), delphinidin chloride (3,5,7,3’,4’,5’-hexahydroxyflavylium chloride) quercetin 3,5,7,3’4’-pentahydroxy-flavone) induce cyanide-insensitive respiration isolated beef heart mitochondrial preparations. Additionally, these aqueous solutions at pH 7.5, as determined by measuring consumption oxygen-dependent spectral changes. It was demonstrated both respiratory bursts autoxidation result production superoxide (O2‒) hydrogen peroxide (H2O2).4