Antioxidation mechanisms of uric acid
- National Institute of Standards and Technology, Gaithersburg, MD (USA)
- Boris Kidric Institute of Nuclear Sciences, Belgrade (Yugoslavia)
One-electron oxidation of uric acid generates the urate radical, which was studied in aqueous solution by pulse radiolysis and oxygen-uptake measurements. Acid-base properties of the uric acid radical were determined, i.e., pK{sub a1} = 3.1 {plus minus} 0.1 and pK{sub a2} = 9.5 {plus minus} 0.1. The reaction of the radical with oxygen was too slow to be measured, k < 10{sup {minus}2} dm{sup 3} mol{sup {minus}1} s{sup {minus}1}. The one-electron-redox potential vs NHE, E{sub 7} = 0.59 V, was derived from the pH dependence of the redox potential, which was fitted through the values measured at pH 7 and 8.9 and those previously determined at pH 13. Rapid reactions of uric acid with oxidizing species and peroxy radicals were indicative of uric acid as a possible water-soluble physiological antioxidant. Rapid reaction of uric acid with the guanyl radical indicates that uric acid may also act as a repair agent of oxidative damage to DNA bases.
- OSTI ID:
- 7155801
- Journal Information:
- Journal of the American Chemical Society; (USA), Vol. 111:15; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
URIC ACID
OXIDATION
AQUEOUS SOLUTIONS
DATA ANALYSIS
DNA
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
RADICALS
RADIOLYSIS
AROMATICS
AZAARENES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DISPERSIONS
HETEROCYCLIC COMPOUNDS
INFORMATION
MIXTURES
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
RADIATION CHEMISTRY
RADIATION EFFECTS
SOLUTIONS
XANTHINES
400201* - Chemical & Physicochemical Properties
550000 - Biomedical Sciences
Basic Studies