Structure-activity relationship of flavonoids active against lard oil oxidation based on quantum chemical analysis

Abstract

In this study, the antioxidant activities of 15 flavonoids against lard oil oxidation were determined by using the Rancimat test. Quercetin, dihydromyricetin, luteolin and kaempferol showed the strongest antioxidant activity, with protection factor values (PF) of 11.50, 11.29, 4.24 and 2.49, respectively. The role of conjugated hydroxyl groups of the B and C ring is discussed. By using the following descriptors: ΔHf (the difference in heat of formation between flavonoids and their free radicals resulted after hydrogen atom donation) and HBC (the number of conjugated hydroxyl groups of the B and C ring), the result obtained in the antioxidant Rancimat test could be successfully explained. © 2009 by the authors; licensee Molecular Diversity Preservation International.