Reaction of HO/sub 2//O/sub 2//sup -/ with. cap alpha. -tocopherol in ethanolic solutions
The HO/sub 2/ perhydroxyl radical reacts with ..cap alpha..-tocopherol in 85% ethanol containing some H/sub 2/SO/sub 4/, EDTA, and O/sub 2/. The resulting transient has a spectral maximum near 390 ..mu... The final product is mostly ..cap alpha..-tocopherylquinone. Best reproducibility for reaction of O/sub 2//sup -/ with ..cap alpha..-tocopherol was obtained in a deoxygenated reaction mixture of 26 +- 3 ..mu..M O/sub 2//sup -/, 0.0565M ..cap alpha..-tocopherol, 5..mu..M EDTA, and 0.005 M KOH in 85% EtOH; the upper limit for the reaction was 6.0 +- 3.0 M/sup -1/ s/sup -1/, indicating that for all practical purposes O/sub 2//sup -/ does not react at all with ..cap alpha..-tocopherol. Preliminary experiments with Trolox, a vitamin E model compound, indicates that it too reacts with HO/sub 2/ but not with O/sub 2//sup -/. Membrane-bound tocopherols in vivo may fulfil a dual antioxidant role. (DLC)
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6869523
- Report Number(s):
- BNL-31889; CONF-821032-1; ON: DE82022303
- Resource Relation:
- Conference: 3. international conference on superoxide and superoxide dismutase, Ellenville, NY, USA, 3 Oct 1982; Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROPEROXY RADICALS
CHEMICAL REACTIONS
SUPEROXIDE RADICALS
VITAMIN E
ABSORPTION SPECTRA
EDTA
ETHANOL
POTASSIUM HYDROXIDES
SULFURIC ACID
ALCOHOLS
ALKALI METAL COMPOUNDS
AMINO ACIDS
CARBOXYLIC ACIDS
CHELATING AGENTS
HYDROGEN COMPOUNDS
HYDROXIDES
HYDROXY COMPOUNDS
INORGANIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
RADICALS
SPECTRA
VITAMINS
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)