| tocopherol | 1. Name given to vitamin E by its discoverer, but now a generic term for vitamin E and compounds chemically related to it, with or without biological activity; similar in chemical structure and properties to vitamins K and coenzyme Q. 2. A methylated tocol or methylated tocotrienol. Mixed tocopherols concentrate, a source of vitamin E, obtained by vacuum distillation of edible vegetable oils or their by-products. (05 Mar 2000) |
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| tocopherol cyclase | <enzyme> Catalyses cyclization of phytyl-hydroquinone to gamma-tocopherol; isolated from the blue-green alga anabaena variabilis Registry number: EC 5.4.99.- (26 Jun 1999) |
| tocopherolquinone | An oxidised tocopherol, formed from the isomeric 2-methyl-2-phytyl-6-chromenol with methyl groups in one or more of positions 5,7, and 8, by migration of H atom from 6-OH to C-4, which yields a 1,4-benzoquinone. Abbreviated TQ and preceded by alpha-, beta-, etc., as in the tocopherols, to indicate degree of methylation. Synonym: tocopherylquinone. (05 Mar 2000) |
| tocopherols | Functions as an antioxidant, binds oxygen free radicals that can cause tissue damage, may also play a protective role in the coronary arteries from the damaging effects of cholesterol. (27 Sep 1997) |
| alpha-tocopherol | <chemical> A light yellow, viscous, odourless, oily liquid that deteriorates on exposure to light, is obtained from wheat germ oil or by synthesis, biologically exhibits the most vitamin E activity of the alpha-tocopherol's, and is an antioxidant retarding rancidity by interfering with the autoxidation of fats. Prepared from natural phytol, it is called 2-ambo-alpha-tocopherol; from synthetic phytol, all-rac-alpha-tocopherol or synt-alpha-tocopherol; also available are d-alpha-tocopheryl acetate, dl-alpha-tocopheryl acetate, d-alpha-tocopheryl acid succinate, and d-alpha-tocopheryl acetate concentrate. One of several forms of vitamin E. Chemical name: 2,5,7,8-tetramethyl-2-(4',8',12'-trimeth yltridecyl)-6-chromanol; 5,7,8-trimethyltocol Synonym: vitamin E. (14 Aug 2000) |
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| beta-tocopherol | 5,8-Dimethyltocol;a lower homolog of alpha-tocopherol, that contains one less methyl group in the aromatic nucleus and is less active biologically; accompanies alpha-T and gamma-beta-tocopherol (05 Mar 2000) |
| gamma-tocopherol | 7,8-Dimethyltocol;a form biologically less active than alpha-gamma-tocopherol (05 Mar 2000) |
| gamma-tocopherol methyltransferase | <enzyme> Forms alpha-tocopherol; enzyme nomenclature name of tocopherol o-methyltransferase is incorrect, since there are no -och3 groups in the product Registry number: EC 2.1.1.95 Synonym: gtc methyltransferase (26 Jun 1999) |
| S-adenosylmethionine-tocopherol methyltransferase | <enzyme> Catalyses methylation of positions 7 or 8 of the tocol ring, forming gamma-tocopherol (7,8-dimethyltocol); see also EC 2.1.1.95, which converts gamma-tocopherol to alpha-tocopherol (5,7,8-trimethyltocol) Registry number: EC 2.1.1.- Synonym: sam-tocopherol methyltransferase (26 Jun 1999) |