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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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 ?
What researchers fail to comprehend is that giving aged men a single antioxidant like alpha tocopherol is not going to reverse seven decades of genetic damage to prostate DNA.
However, similar to our results, Mudgal (2005) and Rajeesh (2006) reported that supplementation of Se and alpha tocopherol, respectively, in the diet of buffalo calves had no effect on blood retinol concentration.
Unfortunately, studies show that high intakes of alpha tocopherol suppress blood and tissue levels of the more important gamma tocopherol.
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.
3) Interestingly, the effects were even more pronounced when 800 mg of alpha tocopherol was added, demonstrating that both forms of vitamin E are synergistically vital for optimal cardiovascular health.
Life Extension long ago warned of increased disease risk in those who only took alpha tocopherol supplements without also taking gamma tocopherol.
Our results support the hypothesis that higher concentrations of serum alpha tocopherol may protect against pancreatic carcinogenesis in smokers," the authors concluded.
If one were to rely only on synthetic alpha tocopherol, the minimum daily dose needed has been shown to exceed 800 IU, (11,12) far greater than the 400 IU ingested every other day by the subjects in this poorly designed study.
We have known for over 10 years that when alpha tocopherol is taken by itself, it displaces critically important gamma tocopherol in our cells.
Subjects taking vitamin E as alpha tocopherol were divided into four groups from the lowest intake ([less than or equal to] 4.
The antioxidant synergism between components extracted from leaves of green tea and endogenous alpha tocopherol in the oxidative damage of red blood cells was observed.
Eighty men and women who had at least three metabolic syndrome features (such as increased waist circumference, elevated triglycerides, hypertension, elevated fasting blood sugar, or low HDL [high-density lipoprotein]) supplemented with 800 milligrams alpha tocopherol, 800 milligrams gamma tocopherol, 800 mg alpha tocopherol plus 800 milligrams gamma tocopherol, or a placebo daily for six weeks.