tocopherol

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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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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

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.
References in periodicals archive ?
Each strain had a control while the other subgroups were provided with ginger, alpha-tocopherol and L-carnitine at the rate of 2%, 250 and 500 mg/kg respectively.
Changes in erythrocytes following supplementation with alpha-tocopherol in children suffering from sickle cell anaemia.
A study in 2012 with approximately 370,000 participants showed higher alpha-tocopherol levels decreased the risk of prostate cancer and diabetes.
That ratio is in line with the ratio of gamma- to alpha-tocopherol in the European diet, although it is lower than the ratio in the American diet.
Al though quantitatively, alpha-tocopherol comprises the bulk of vitamin E found in the epidermis, tocotrienols-applied orally or topically-also deliver to viable skin layers.
in 2008 found that a stable topical preparation of 15% L-ascorbic acid, 1% alpha-tocopherol, and 0.5% ferulic acid protected human skin in vivo from UV-induced damage, specifically erythema and apoptosis.
The bactericidal activity of Levofloxacin and immune stimulant activity of Alpha-tocopherol is the basis for superior efficacy in treatment bovine endometritis.
Alpha-Tocopherol in human spermatozoa and seminal plasma: relationships with motility, antioxidant enzymes and leukocytes.
An increasing amount of positive research is pointing towards natural fullspectrum palm tocotrienol complex as having unique and far more significant health improvement potential than conventional vitamin E alpha-tocopherol. Recent clinical trials with Tocomin and Tocomin SupraBio have shown that these two branded ingredients support neuro-, cardiovascular and prostate health, as well as skin health.
Effect of vitamin e supplementation and partial substitution of poly with mono-unsaturated fatty acids in pig's diets on muscle, and microssome extract alpha-tocopherol concentration and lipid oxidation.