Theoretical Study of the Radical Scavenging Potencies of the Metabolites of Quercetin and Kaempferol
A lot of studies have evidenced the beneficial effects of flavonoids in diseases linked to oxidative stress. Radical scavenging is one of the possible ways of action through two processes: transfer of hydrogen radical or electron. The enthalpies corresponding to these two processes can be calculated with a good accuracy to evaluate the radical scavenging properties of polyphenols. If a lot of studies have determined the radical scavenging properties of aglycone or glycosylated flavonoids, no theoretical calculations have been performed on the metabolites of these compounds that are the active molecules in tissues or in human plasma. In this paper, the enthalpies corresponding to the two radical scavenging processes, transfer of a hydrogen atom or an electron, are accurately calculated for the metabolites of two abundant flavonoids, quercetin and kaempferol and the evolution of radical scavenging properties consecutive to the metabolism is discussed, giving some insight in the real active radical scavengers in the body.