tocopherol


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to 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.
..... Click the link for more information.
.

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 ?
Tocopherol and Free fatty acids analysis: Tocopherol analysis was carried out according to the method suggested by Swiglo and Sikorska (2004).
Importance of tocopherols beyond alpha-tocopherol: evidence from animal and human studies.
The significant variation among the reduced palmitate lines for the individual tocopherols and their percentages of the total tocopherol indicated that it should be possible to select for the amount and proportion of each component (Table 1).
Vitamin E (tocopherols) is considered to be an essential dietary nutrient for crustaceans (Conklin 1997).
Participants were divided into thirds, ranked according to their serum concentrations of carotenoids, alpha tocopherol and selenium measured in 1996 and monitored for histologically confirmed BCC and SCC tumors through until 2004.
This study revealed that Zendehrood variety had the highest level of tocopherol and was more stable in the Rancimat test and it is the most useful variety for future commercial production in the region.
Hitherto, alpha tocopherol supplementation alone and in combination with ascorbic acid significantly protected the experimental animals against oxidative stress induced by restraint stress in mesh wire restrainers in our study.
Efficacy of intrauterine use of levofloxacin and alpha tocopherol on conception rate in repeat breeder crossbred cows.
The antioxidant functions of tocopherol and tocotrienol homologues in oils, fats and food systems.