Gamma tocopherol

Reboul, E, Thap, S, Perrot, E, Amiot, MJ, Lairon, D, and Borel, P, 2007a. Effect of the main dietary antioxidants (carotenoids, gamma-tocopherol, polyphenols, and vitamin C) on alpha-tocopherol absorption. Eur J Clin Nutr 61, 1167-1173. 

Li, D., Saldeen, T., Mehta, J.L., 1999, gamma-tocopherol decreases ox-LDL-mediated activation of nuclear factor-kappaB and apoptosis in human coronary artery endothelial cells. Biochem. Biophys. Res. Commun. 259 157-161. 

Wyatt CJ, Carballido SP, Mendez RO, Alpha- and gamma-tocopherol content of selected foods in the Mexican diet Effect of cooking losses, J Agricultural and Food Chemistry 46 4657-4661, 1998. 

Com and sesame oils increase serum gamma-tocopherol concentrations in S1017 healthy Swedish women. J Nutr 2001 ... 

Hensley, K., Williamson, K. S., and Floyd, R. A. (2000). Measurement of 3-nitrotyrosine and 5-nitro-gamma-tocopherol by high-performance liquid chromatography with electrochemical detection. Free Radic. Biol. Med. 28 520-528. 

Helzlsouer, K.J. Huang, H.Y. Alberg, A.J. Hoffman, S. Burke, A. Norkus, A.E.P. Morris, J.S. Comstock, G.W. 2000. Association between alpha-tocopherol, gamma-tocopherol, selenium, and subsequent prostate cancer. J. Natl. Cancer Inst. 92 2018-2023. 

Jiang, C.S. Shigenaga, M.K. Ames, B.N. 2001. Gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention. Am. J. Clin. Nutr. 74 714-722. 

Wagner, K.H. Kamal-Eldin, A. Elmadfa, I. 2004. Gamma-tocopherol - an underestimated vitamin Ann. Nutr. Metab. 48 169-188. 

Jiang Q, Christen S, Shigenaga MK, and Ames BN (2001) Gamma-tocopherol, the major form ofvitaminEintheUS diet, deserves mote attention. American Journalof Clinical... 

Milatovic, D., VanRollins, M., Li, K., Montine, K.S., Montine, T.J. (2005b). Suppression of murine cerebral F2-isoprostanes and F4-neuroprostanes bom excitotoxicity and innate immune response in vivo by alpha- or gamma-tocopherol. J. Chroma-togr. B Analyt. Technol. Biomed. Life Set 827 88-93. 

The dominance of tocopherols, namely, alpha-, beta-, gamma-, and delta- and the corresponding tocotrienols, depends on the type of oil under investigation. Thus, tocotrienols occur primarily in palm and rice bran oils. Meanwhile, tocopherols are more widely present in different oils. However, their proportions in different oils is dependent on the source material. As an example, sunflower oil contains mainly alpha-tocopherol and very small amounts of other tocopherols, whereas soybean oil contains mainly gamma-tocopherol with decreasing amounts of delta-, alpha-, and beta-tocopherols as determined by high-performance liquid chromatography. 

Flaxseed oils contain much lower amounts of tocopherols, half of the amount present in sunflower and canola oils and one-third of that present in soybean oil (Table 2). A lower content of these antioxidants makes these oils even more susceptible to oxidation. Gamma-tocopherol was found as the main tocopherol in flax oils, with a contribution of about 80% to the total amount. This makes flax oil comparable with soybean oil. Among unique antioxidants detected in flax oils was plasto-chromanol-8. This compound is a derivative of gamma tocotrienol with twice as long unsaturated side chain. Plastochromanol-8 was found to be a more efficient antioxidant than any tocopherols isomer (15). A low content of tocopherols in flaxseed did not make them more susceptible to oxidation experiments showed that milled flaxseed could be stored for 28 months at ambient temperatures without measurable changes in oxidation products. This can be attributed to the presence of antioxidants other than tocopherols in the seeds (16). 

The amount of tocopherols in perilla oil is higher compared with flax oil, and a similar contribution of gamma-tocopherol, above 90%, was observed (Table 4). Shin and Kim (49) analyzed perilla oil for lipid composition and established that it contained more than 90% triacylglycerols, 4% glycolipids, and 2% of each phospholipids and sterol esters. 

Tocopherols are considered a moderate antioxidant in the peanut oil. The Codex Alimentaris standard for tocopherols in peanut oil (103) indicates a range of 48-373 mg/kg for alpha-tocopherol, 0-140 mg/kg for beta-tocopherol, 88-389 mg/kg for gamma-tocopherol, and 0-22 mg/kg for delta-tocopherol. Total tocopherol... 

Alfa-tocopherol is a good antioxidant against photooxidation (38). Table 2 shows that corn and cottonseed oils are rich in gamma-tocopherol, while sunflower oil contains very little gamma-tocopherol. This may explain why cottonseed oil and com oil have superior frying stability than the sunflower oil even without hydrogenation. 

Wolf, G. (1997) gamma-Tocopherol an efficient protector of lipids against nitric oxide- initiated peroxidative damage. NutrRev 55, 376-8. 

Christen, S., Woodall, A. A., Shigenaga, M. K., Southwell-Keely, P. T., Duncan, M. W., and Ames, B. N. (1997) gamma-tocopherol traps mutagenic electrophiles such as NO(X) and complements alpha-tocopherol physiological implications. Proc Natl Acad Sci USA94, 3217-22. 

Goss, S. P., Hogg, N., and Kalyanaraman, B. (1999) The effect of alpha-tocopherol on the nitration of gamma-tocopherol by peroxynitrite. Arch Biochem Biophys 363, 333-40. 

Saldeen, T.. Li, D., and Mehta, J. L. (1999) Differential effects of alpha- and gamma-tocopherol on low-density lipoprotein oxidation, superoxide activity, platelet aggregation and arterial thrombogenesis. J Am Coll Cardiol 34, 1208-15. 

Similar considerations apply to beta, delta, and gamma tocopherol and tocopherol esters. 

Naturally occurring tocopherols are obtained by the extraction or molecular distillation of steam distillates of vegetable oils for example, alpha tocopherol occurs in concentrations of 0.1-0.3% in corn, rapeseed, soybean, sunflower, and wheat germ oils. Beta and gamma tocopherol are usually found in natural sources along with alpha tocopherol. Racemic synthetic tocopherols may be prepared by the condensation of the appropriate methylated hydroquinone with racemic isophy-tol.<">... 

Comments less active biologically than alpha tocopherol. Obtained along with alpha tocopherol and gamma tocopherol from natural sources. Beta tocopherol is very stable to heat and alkalis and is slowly oxidized by atmospheric oxygen. 

Comments occurs in natural sources along with alpha and beta tocopherol. Gamma tocopherol is biologically less active than alpha tocopherol. Very stable to heat and alkalis slowly oxidized by atmospheric oxygen and gradually darkens on exposure to light. 

Comments tocopherols excipient is described in the USPNF 23 as a vegetable oil solution containing not less than 50.0% of total tocopherols, of which not less than 80.0% consists of varying amounts of beta, delta, and gamma tocopherols. 

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