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Electron spin resonance spectra of the chromanoxyl radicals derived from tocopherols (vitamin E) and their related compounds
Author(s) -
Matsuo Mitsuyoshi,
Matsumoto Shigenobu
Publication year - 1983
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02534695
Subject(s) - radical , electron paramagnetic resonance , chemistry , vitamin e , antioxidant , photochemistry , organic chemistry , nuclear magnetic resonance , physics
The well resolved electron spin resonance (ESR) of the tocopheroxyl and chromanoxyl radicals derived from α‐, β‐, γ‐ and δ‐tocopherols (vitamin E), 5,7‐dimethyltocol, tocol and their model compounds in degassed toluene by treatment with 2,2‐diphenyl‐1‐picrylhydrazyl were recorded. Their hyperfine coupling constants were determined and assigned using spectrum simulation. Their g‐factors were also measured. On the basis of these parameters, the α‐tocopheroxyl radical is similar to the 2,2,5,7,8‐pentamethylchroman‐6‐oxyl, 5,7‐dimethyltocoxyl and 2,2,5,7‐tetramethylchroman‐6‐oxyl radicals. This suggests that the presence of methyl groups at C‐5 and C‐7 in tocopherols and chroman‐6‐ols is of great importance to their antioxidant action. The ESR parameters obtained here are very useful for the identification and quantification of a variety of tocopheroxyl radicals.