Faytamiin E waa fiitamiin aan ur lahayn oo aan dhadhamin lahayn dufan huruud ah oo khafiif ah oo milmay oo leh antioxidant, kansarka, ka hortagga bararka iyo hawlo kale. Marka loo eego qaab-dhismeedka molecular, waxa loo qaybin karaa laba qaybood: tocopherols iyo tocotrienols. Qayb kasta waxaa loo qaybiyaa afar nooc oo ku salaysan booska methyl ee giraanta koromophore: alfa, beta, gamma, iyo delta [1-2]. Isku-dhafka la xidhiidha tocopherols, sida tocotrienols, waxay leeyihiin waxqabad gaar ah marka beddelayaashu ay kala duwan yihiin, laakiin waxqabadka tocopherols si weyn ayaa loo yareeyaa.

Tocopherol iyo tocotrienol labaduba waxay leeyihiin saameyn antioxidant xoog leh. Sababtoo ah dhaqdhaqaaqa alfa tocopherol wareejinta borotiinka (alpha TP) iyo borotiinka isku xidhka tocopherol (TBP) ee jirka, tocopherol si fudud ayaa loo nuugo oo jidhku u isticmaalo. Sidaa darteed, alfa tocopherol waxaa loo arkaa inay tahay muujinta ugu weyn ee fitamiin E ee firfircoonida antioxidant ee jirka. Alpha tocopherol, oo leh qaacido molecular oo ah C29H50O2 iyo miisaanka kelli ee 430.5, ayaa loo qaybiyaa laba nooc oo ku salaysan isha laga helo: dabiiciga iyo synthetic, oo lagu tilmaamay nooca D iyo nooca L, siday u kala horreeyaan. Alfa tocopherol-ka dabiiciga ah wuxuu ku jiraa qaabka R (RRR), halka alfa tocopherol si macmal ah loo sameeyay uu ku jiro qaabka RS (RRR, RSR, RRS, RSS, SRR, SSR, SRS, SSS). Isbeddelku wuxuu la xiriiraa dhaqdhaqaaqiisa, cilmi-baaristu waxay ogaatay in kaliya alfa tocopherol oo leh 2R ama ka badan uu isticmaali karo oo nuugi karo jirka. Sidaa darteed, alfa tocopherol ee dabiiciga ah waxay leedahay qiime nafaqo oo sarreeya waxayna ka badbaadsan tahay alfa tocopherol si dabiici ah loo farsameeyey.