Production of Hydrogen Peroxide by Polyphenols and Polyphenol-rich Beverages under Quasi-physiological Conditions

Abstract

  To investigate the ability of the production of H₂O₂ by polyphenols, we incubated various phenolic compounds and natural polyphenols under a quasi-physiological pH and temperature (pH 7.4, 37°C), and then measured the formation of H₂O₂ by the ferrous ion oxidation-xylenol orange assay. Pyrocatechol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, and polyphenols such as catechins yielded a significant amount of H₂O₂. We also examined the effects of a metal chelator, pH, and O₂ on the H₂O₂-generating property, and the generation of H₂O₂ by the polyphenol-rich beverages, green tea, black tea, and coffee, was determined. The features of the H₂O₂-generating property of green tea, black tea, and coffee were in good agreement with that of phenolic compounds, suggesting that polyphenols are responsible for the generation of H₂O₂ in beverages. From the results, the possible significances of the H₂O₂-generating property of polyphenols for biological systems are discussed.