||Inclusion Complex of 2,2-Diphenyl-1-picrylhydrazyl Radical with beta-Cyclodextrin as a Redox Probe in Aqueous Systems
Nakanishi, Ikuo ,
Ozawa, ToshihikoMatsumoto, Kenichiro
A stable radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH), exhibits reversible one-electron reduction and oxidation behavior with characteristic color changes. In fact, DPPH has been used as a dosimeter in radiation chemistry as well as a reactivity model of reactive oxygen species to evaluate the activity of antioxidants in non-aqueous and semi-aqueous media. However, the insolubility of DPPH in water has precluded its use in aqueous systems, in particular, physiological concentration (> 0.1 M) of buffer solutions. Recently, we have succeeded in solubilizing DPPH in water using beta-cyclodextrin (beta-CD). In this study, it is demonstrated that beta-CD solubilized DPPH can be used not only as a radiation dosimeter in water but also as a powerful tool to evaluate activity of water-soluble antioxidants in concentrated buffer solutions.
Gordon Research Conference on Oxygen Radicals