Spectra and structure of alpha-tocopherol radicals produced in anoxic media.
Free Radic Biol Med
; 11(4): 349-52, 1991.
Article
em En
| MEDLINE
| ID: mdl-1665834
ABSTRACT
Electron spin resonance and flash photolysis studies have been combined to determine, amid conflicting reports from radiolysis studies, the spectrum for the phenoxyl radical of alpha-tocopherol. Triplet state ketones were used to abstract the alpha-tocopherol phenolic hydrogen in order to obtain both the transient ESR spectrum and optical spectrum. Analysis of the ESR data yields g = 2.00469, a(H, 5-CCH3) = 6.04G, a(H,7-CCH3) = 4.51G, a(H, CH2) = 1.38G, a(H', CH2) = 1.49G, and a(H,8-CCH3) = 0.89G. The g factor shows large spin population on oxygen in this radical and demonstrates conclusively involvement of the phenoxyl radical. Both spectra were in agreement with those produced by radiolysis of alpha-tocopherol in N2 saturated EtOH. While the spectral characteristics of the phenoxyl radical now appear to be clarified, uncertainties remain concerning optical spectra for radiolysis of alpha-tocopherol in air- and oxygen-containing systems.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina E
Idioma:
En
Revista:
Free Radic Biol Med
Assunto da revista:
BIOQUIMICA
/
MEDICINA
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
França