Effect of Temperature, Cholesterol Content, and Antioxidant Structure on the Mobility of Vitamin E Constituents in Biomembrane Models Studied by Laterally Diffusion-Controlled Fluorescence Quenching

摘要: Kinetic parameters relevant for the antioxidant activity of vitamin E constituents (α, β, γ, and δ homologues tocopherols tocotrienols) an amphiphilic C derivative, l-ascorbyl 6-palmitate, were determined. Fluorescence quenching experiments 2,3-diazabicyclo[2.2.2]oct-2-ene in homogeneous acetonitrile−water mixtures afforded reactivity trends terms intermolecular rate constants, while Fluorazophore-L liposomes provided lateral diffusion coefficients understanding their biological membranes. The solution was not influenced by nature isoprenoid tail (tocopherol versus tocotrienol), but dependent on methylation pattern. resulting order (α > β = γ δ) found to be line with reactivities toward peroxyl radicals as well phenolic O−H bond dissociation energies. mutual coefficient POPC same, within error, di...