Anti-oxidant activity of flavonols: Reactivity with potassium superoxide in the heterogeneous phase

Article abstract of DOI:10.1016/S0040-4020(01)85507-1

Oxidation of flavonols by potassium superoxide (KO₂) in heterogeneous aprotic media yields acids and aldehydes by opening of ring C, if the latter contains an ethylenic double bond substituted by an OH group. A mechanism is proposed for this reaction. Other flavonoids like flavones, flavans and flavanones induce only the disproportionation of superoxide anion, without undergoing further oxidation; these flavonoids are therefore anti-oxidants of particular interest.