tocopherol

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Related to Alpha tocopherol: vitamin E

tocopherol:

see vitaminvitamin,
group of organic substances that are required in the diet of humans and animals for normal growth, maintenance of life, and normal reproduction. Vitamins act as catalysts; very often either the vitamins themselves are coenzymes, or they form integral parts of coenzymes.
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The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Tocopherol

 

any vitamin of the E group. Tocopherols are similar in chemical structure and are contained in large quantities in vegetable oils. Eight tocopherols that have vitamin activity are known; they are designated by the Greek letters et, β, 7, and so on. Although only a tocopherol, which is the most active, was formerly considered to be vitamin E, the term subsequently came to include the entire group of natural and synthetic tocopherols, which have the activity of α-tocopherol to varying degrees (α-tocopherol was discovered in the 1920’s and was extracted in pure form in 1936; P. Karrer synthesized it chemically in 1938).

Chemically, tocopherols are derivatives of chromane (a two-ring aromatic system) combined with an isoprenoid side chain. Tocopherols are transparent, oily liquids that are soluble only in organic solvents; they remain stable upon heating. They are widespread in nature but are synthesized only by plants. Animals and man obtain them from food. The highest tocopherol content is found in the germs of cereals and in the oils extracted from them. With a normal diet, E avitaminosis and hypovitaminosis occur rarely. Insufficient intake of vitamin E in experimental animals leads to sterility, muscular dystrophy, disorders of the central nervous system, increased hemolysis, and hypothyroidism. Tocopherol deficiency causes increased permeability or complete disintegration of biological membranes, including the membranes of the mitochondria and lysosomes. It is assumed that one of the functions of tocopherols in cells is to prevent the formation of peroxides from unsaturated fatty acids—that is, to play the role of natural antioxidants. In many cases, pathological symptoms that result from a tocopherol-deficient diet may be eliminated or prevented by certain antioxidants. The biochemical functions of tocopherols are also associated with tissue respiration processes.

Tocopherols are used in medicine to treat certain nervous, skin, gynecological, and cardiovascular disorders. Supplements added to animal feeds sharply reduce miscarriages in cows and eliminate motor disorders and paralyses in young birds. Tocopherols are used as natural antioxidants to stabilize vitamins A and D and to prevent vegetable oils from becoming rancid.

REFERENCE

Shaternikov, V. A. “Vitamin E.” In Vitaminy. Moscow, 1974. Chapter 5.

N. N. ZAITSEVA

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

tocopherol

[tə′käf·ə‚röl]
(organic chemistry)
Any of several substances having vitamin E activity that occur naturally in certain oils; α-tocopherol possesses the highest biological activity.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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A simple micro method for determination of plasma levels of alpha tocopherol (Vitamin E) in Pakistani normal adults.
this change in the alpha tocopherol group translated into a delay in clinical progression of 19% per year compared with placebo, or a delay of approximately 6.2 months over the follow-up period.
Alpha tocopherol is the form of vitamin E used most commonly in commercial supplements.
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Retinol, alpha tocopherol, lycopene and beta-carotene, simultaneously determined in plasma by isocratic liquid chromatography.
There is no evidence that antioxidants like alpha tocopherol and selenium would protect against this kind of prostate cancer induced by prolonged excess estrogen exposure.
Alpha tocopherol is the major form of vitamin E found in human tissues.
Evidence for alpha tocopherol regeneration reaction of green tea polyphenols in SDS micelles.
Only one of these stereoisomers is bioidentical to natural alpha tocopherol (RRR-alpha-tocopherol or d-alphatocopherol).
A rat study showed that gamma tocopherol, but not alpha tocopherol, exhibited potent reduction of PGE2 and leukotriene B4, powerful pro-inflammatory end products of the COX-2 and 5-LOX pathways, respectively.
In 1997, the Life Extension Foundation[R] warned that taking-only the alpha tocopherol form of vitamin E could displace critically important gamma tocopherol in the body.