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Evidence for a possible role of 3‐hydroxyanthranilic acid as an antioxidant
Author(s) -
Chadha Ridhima,
Mahal H. S.,
Mukherjee Tulsi,
Kapoor S.
Publication year - 2009
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1485
Subject(s) - chemistry , radiolysis , radical , reaction rate constant , electron transfer , guanosine , photochemistry , one electron reduction , antioxidant , medicinal chemistry , solvated electron , radical ion , kinetics , organic chemistry , ion , biochemistry , physics , electrode , quantum mechanics , electrochemistry
The reactions of 3‐hydroxyanthranilic acid (3‐OHAA) with N 3 • , NO 2 • , NO • , CCl 3 O 2 • , and OH • radicals were examined using a pulse radiolysis technique mainly at pH 7. The bimolecular electron transfer from secondary one‐electron oxidants results in the formation of anilino radical ( λ max ≅ 380 nm). The rate constant for the reaction of N 3 • radical with 3‐OHAA at pH 7 was found to be 6.3 × 10 9 dm 3 mol −1 s −1 . It was observed that the 3‐OHAA reacts with oxygen centered radicals. The repair rate constant for the electron transfer reaction from 3‐OHAA to guanosine radical and chlorpromazine cation radical was also examined using a pulse radiolysis technique. Kinetic studies indicate that 3‐OHAA may act as an antioxidant to repair free‐radical damage to above mentioned biologically important compounds. The rate constants of electron transfer from the 3‐OHAA to the guanosine and chlorpromazine radicals were determined. The one‐electron reduction potential for 3‐OHAA radical was found to be 0.53 ± 0.06 V versus NHE. Copyright © 2008 John Wiley & Sons, Ltd.