Application of Electrochemiluminescence for the Evaluation of the Antioxidant Capacity of Some Phenolic Compounds Against Superoxide Anion Radicals

作者：Matsuoka Masanori; Jin Jiye^*

来源：Analytical Sciences, 2015, 31(7): 629-634.

DOI：10.2116/analsci.31.629

• Superoxide anion
• phenolic compounds
• antioxidant capacity
• electrochemiluminescence
• lucigenin

This paper for the first time reports on novel and non-enzymatic method for studying the free radical-scavenging properties of phenolic compounds against superoxide anion radicals (O-2(center dot-)) by using the cathodic electrochemiluminescence (ECL) of lucigenin (Luc(2+)). The ECL of Luc(2+) at a glassy carbon (GC) electrode is observed in an aeration electrolytic solution (pH 7), which is believed to be due to the reaction of a one-electron reduced form of Luc(2+) (i.e. a radical cation, Luc.(+)) with in situ electrogenerated O-2(center dot-). The ECL intensity is dependent on the concentration of dissolved oxygen, and is suppressed dramatically by superoxide dismutase (SOD), a typical O-2(center dot-) scavenger. Since the coexisting hydrogen peroxide (H2O2) has no influence on the cathodic ECL of Luc(2+), it is thus suggested that the ECL signal specifically reflected the O-2(center dot-) concentration level generated at the electrode surface. When phenolic compounds were added into the solution, this resulted in the inhibition of ECL signals due to the elimination of O-2(center dot-). The ECL inhibition rate measured at each concentration was compared against the SOD equivalent (U mL(-1)), and the relative antioxidant efficiency, K-80 (U mmol(-1) equivalent SOD), was used to evaluate the antioxidant activity of some phenolic compounds, including flavonoids, in this study. Structurally different water-soluble phenols were compared, and those compounds containing to catechol skeletal structure are found to present the higher antioxidant capacity.

• 出版日期2015-7