Tocopherols, lipid-soluble antioxidants play a crucial role in the antioxidant defense system in higher plants. The antioxidant function of α-tocopherol has been widely studied; however, experimental data on the formation of its oxidation products is missing. In this study, we attempt to provide spectroscopic evidence on the detection of oxidation products of α-tocopherol formed by its interaction with singlet oxygen and lipid peroxyl radical. Singlet oxygen was formed using photosensitizer rose bengal and thylakoid membranes isolated from Arabidopsis thaliana. Singlet oxygen reacts with polyunsaturated fatty acid forming lipid hydroperoxide which is oxidized by ferric iron to lipid peroxyl radical. The addition of singlet oxygen to double bond carbon on the chromanol head of α-tocopherol forms α-tocopherol hydroperoxide detected using fluorescent probe swallow-tailed perylene derivative. The decomposition of α-tocopherol hydroperoxide forms α-tocopherol quinone. The hydrogen abstraction from α-tocopherol by lipid peroxyl radical forms α-tocopheroxyl radical detected by electron paramagnetic resonance. Quantification of lipid and protein hydroperoxide from the wild type and tocopherol deficient (vte1) mutant Arabidopsis leaves using a colorimetric ferrous oxidation-xylenol orange assay reveals that α-tocopherol prevents formation of both lipid and protein hydroperoxides at high light. Identification of oxidation products of α-tocopherol might contribute to a better understanding of the protective role of α-tocopherol in the prevention of oxidative damage in higher plants at high light.

• MeSH
• alfa-tokoferol chemie   metabolismus   MeSH
• antioxidancia chemie   metabolismus   MeSH
• Arabidopsis genetika   růst a vývoj   metabolismus   účinky záření   MeSH
• lipidové peroxidy chemie   metabolismus   MeSH
• oxidace-redukce MeSH
• oxidační stres * MeSH
• peroxid vodíku chemie   metabolismus   MeSH
• singletový kyslík chemie   metabolismus   MeSH
• světlo škodlivé účinky   MeSH
• vitamin E chemie   metabolismus   MeSH
• volné radikály chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alfa-tokoferol MeSH
• antioxidancia MeSH
• lipidové peroxidy MeSH
• peroxid vodíku MeSH
• singletový kyslík MeSH
• tocopheroxy radical MeSH Prohlížeč
• vitamin E MeSH
• volné radikály MeSH