Kinetic Investigation of Reaction of Ascorbate and Hydroxyl Radical Adduct of DMPO (5,5-Dimethyl-1-pyrroline N-Oxide) Studied by Stopped-flow ESR

Sakurai Y; Sanuki H; Komatsu-Watanabe R; Ideguchi T; Yanagi N; Kawai K; Kanaori K; Tajima K

Chemistry Letters, Vol.37, No.12, 1270-1271, 2008

DOI10.1246/cl.2008.1270 Export Citation

Kinetic Investigation of Reaction of Ascorbate and Hydroxyl Radical Adduct of DMPO (5,5-Dimethyl-1-pyrroline N-Oxide) Studied by Stopped-flow ESR

Sakurai Y, Sanuki H, Komatsu-Watanabe R, Ideguchi T, Yanagi N, Kawai K, Kanaori K, Tajima K

By means of a stopped-flow electron spin resonance (ESR) method, the second-order rate constant, defined for reduction of the hydroxyl radical adduct of 5,5-dimethyl-1-pyrroline N-oxide (DMPO/OH) by ascorbic acid at pH 7.4, was evaluated to be 5.2 +/- 0.2 x 10(3) M-1 s(-1), which was at least 700 times faster than that of 2,2,6,6-tetramethyl-4-hydroxylpiperidine-N-oxyl (TEMPOL) radical (7 M-1 s(-1)).