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A tocol with three double bonds in the side chain, that is, with three additional double bonds in the phytyl chain. 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 α-, β-, 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.