Application Notes:
beta-tocopherol is one of the forms of vitamin E, which is well known for its antioxidant activity.1,2 beta-tocopherol, due to
its having only one methyl group ortho to the phenolic hydroxyl group, has slightly less antioxidant activity in vivo than
alpha-tocopherol which has two ortho-methyl groups. Vitamin E inhibits lipid oxidation by donating its phenolic hydrogen to
lipid free radicals.3 Antioxidant activity in vivo is normally lpha>beta>delta>gamma but the antioxidant potency may
depend on various chemical and physical situations.4 The ortho-methyl substitution of the chroman head plays a vital role in
the antioxidant activity of tocopherols while the phytyl tail is very important for proper positioning in the biomembranes. The
antioxidant properties of vitamin E may delay memory loss in Down’s syndrome patients due to their protection from
harmful oxidation caused by excess activity of Superoxide dismutase. Vitamin E is only naturally produced in plants, algae,
and some cyanobacteria and is therefore an important dietary nutrient for humans and animals.
References:
1. Afaf Kamal-Eldin and Lars-Ake Appelqvist The chemistry and antioxidant properties of tocopherols and tocotrienols, Lipids, July; 31 (7): 671-701, 1996
2. G. W. Burton, and M. G. Traber Vitamin E: Antioxidant Activity, Biokinetics, and Bioavailability, Annual Review of Nutrition, July Vol. 10: 357-382, 1990
3. G. W. Burton and K. Ingold Autoxidation of biological molecules. 1. Antioxidant activity of vitamin E and related chain-breaking phenolic antioxidants in vitro, U. J. Am. Chem. Soc., 103, 6472-6477, 1981
4. Anchalee Sirikhachornkit, Jai W. Shin, Irene Baroli, and Krishna K. Niyogi Replacement of a -tocopherol by ß -tocopherol enhances resistance to photo-oxidative stress in a xanthophyll-deficient strain of Chlamydomonas reinhardtii, Eukaryotic Cell, doi:10.1128, 2009