| 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) |
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| 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) |
| tocopherylquinone | 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) |
| tocophobia | <psychology> Fear of childbirth. (12 Dec 1998) |
| tocoquinone | Class name for the 2,3,5-trimethyl-6-multiprenyl-1,4-benzoquinones. (05 Mar 2000) |
| tocororo | <zoology> A cuban trogon (Priotelus temnurus) having a serrated bill and a tail concave at the end. Origin: Probably from the native name through the Spanish: cf. Sp. Tocororo. Source: Websters Dictionary (01 Mar 1998) |
| tocotrienol | A tocol with three double bonds in the side chain, i.e., with three additional double bonds in the phytyl chain, thus a 6-(3',7',11',15'-tetramethyl-2',6',10',14'-hexadecatetraenyl)-1,4-hydroquinone or a 2-methyl-2-(4,8,12-trimethyltrideca-3,7,11-trienyl)chroman-6-ol. The natural products carry methyls at one or more of positions 5, 7, and 8 of the chromanol and are thus identical, except for the unsaturation in the phytyl-like side chain, to the tocopherols; also analogous is the cyclization to form a chromanol derivative and oxidation to form the tocotrienolquinones (or chromenols). Abbreviated T-n (hydroquinone form) or TQ-n (quinone form) and preceded by alpha-, beta-, etc., as in the tocopherols, to indicate degree of methylation (the n indicates the number of intact isoprene or prenyl units remaining in the chromanol or chromenol form). Tocotrienol terminology is used to indicate relationships to tocols and tocoenols (vitamin E-like), the chromanol terminology to indicate relationship to the isoprenoidal compounds of the vitamin K and coenzyme Q series. (05 Mar 2000) |
| tocotrienolquinone | A tocotrienol in which the hydroquinone has been oxidised to a quinone (the chromanol has become a chromenol); the tocotrienolquinone's carry a, b, g, and d prefixes in accordance with the degree of methylation, as do the tocotrienols. (05 Mar 2000) |