Kinetic study of quenching reactions of singlet oxygen and scavenging reactions of free radicals by α‐, β‐, λ‐ and σ‐tocopheramines in ethanol solution and micellar dispersion
- 1 November 1994
- Vol. 29 (11) , 799-802
- https://doi.org/10.1007/bf02536703
Abstract
Quenching reactions of singlet oxygen and scavenging reactions of free radicals by α‐, β‐, λ‐ and σ‐tocopheramines (Toc‐amines) were investigated spectrophotometrically in ethanol and Triton X‐100 micellar dispersions. The rate constants of quenching of singlet oxygen (kQ) by α‐, β‐, λ‐ and σ‐Toc‐amines increased as the total electron donating capacity of the methyl groups at the aromatic ring increased. A plot of logkQ vs. peak oxidation potential (Ep) was found to be linear and the slope was negative. Similar results were obtained for scavenging of a phenoxyl radical (PhO.). The results suggest that charge transfer plays an important role in these reactions. ThekQ values were found to be 1.30–2.57 times as large askQ for α‐tocopherol (α‐Toc). Although α‐Toc has the highest antioxidant activity among natural tocopherols and related phenols, Toc‐amines also can serve as antioxidants.Keywords
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