Editing Tocopherol (section)

===Tocotrienols===
{{Main|Tocotrienol}}
Tocotrienols also belong to the vitamin E family. Tocotrienols have four natural 2' d-isomers (they have a stereoisomeric carbon only at the 2' ring-tail position). The four tocotrienols (in order of decreasing methylation: d-α-, d-β-, d-γ-, and d-δ-tocotrienol) have structures corresponding to the four tocopherols, except with an unsaturated bond in each of the three [[isoprene]] units that form the hydrocarbon tail, whereas tocopherols have a saturated phytyl tail (the phytyl tail of tocopherols gives the possibility for 2 more stereoisomeric sites in these molecules that tocotrienols do not have). Tocotrienols have seen less research as compared to tocopherols.<ref>{{cite journal | vauthors = Sen CK, Khanna S, Roy S | title = Tocotrienols: Vitamin E beyond tocopherols | journal = Life Sciences | volume = 78 | issue = 18 | pages = 2088–2098 | date = March 2006 | pmid = 16458936 | pmc = 1790869 | doi = 10.1016/j.lfs.2005.12.001 }}</ref>