Analytical Sciences


Abstract − Analytical Sciences, 17(5), 599 (2001).

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials
Bin YANG,* Akira KOTANI,** Kensuke ARAI,** and Fumiyo KUSU** 
*Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine, Beijing, 100700, China
**School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
A simple electrochemical method for estimating the antioxidant activity (AA) of flavonoids has been developed. The proposed method is based on a measurement of the half-wave potential (E1/2) of the first oxidation wave of flavonoids by using flow-through column electrolysis. At the same time, the lipid peroxidation (LPO) inhibiting effects of these flavonoids were determined. A quantitative structure–activity relationship was obtained to describe the AA of flavonoids: IC50(uM) = 30.36 + 151.50E1/2 (V) - 12.63log P (r = 0.852), where IC50 represents the concentration for 50% inhibition of LPO, and P represents the octanol/water partition coefficient. This method is expected to be useful for the quick screening of flavonoid antioxidants, and evaluating the AA of flavonoid-containing foods and medicinal plants.