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Names | |
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IUPAC name
(2R)-2,5,7,8-Tetramethyl-2-[(4R,8R)-(4,8,12-trimethyltridecyl)]chroman-6-ol
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Identifiers | |
3D model (JSmol)
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ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.000.375 ![]() |
EC Number |
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E number | E307a (antioxidants, ...) |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C29H50O2 | |
Molar mass | 430.71 g/mol |
Appearance | yellow-brown viscous liquid |
Density | 0.950 g/cm3 |
Melting point | 2.5 to 3.5 °C (36.5 to 38.3 °F; 275.6 to 276.6 K) |
Boiling point | 200 to 220 °C (392 to 428 °F; 473 to 493 K) at 0.1 mmHg |
Pharmacology | |
A11HA03 (WHO) | |
Hazards | |
NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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Infobox references | |
?-Tocopherol is a type of vitamin E. It has E number "E307". Vitamin E exists in eight different forms, four tocopherols and four tocotrienols. All feature a chromane ring, with a hydroxyl group that can donate a hydrogen atom to reduce free radicals and a hydrophobic side chain which allows for penetration into biological membranes. Compared to the others, ?-tocopherol is preferentially absorbed and accumulated in humans.
Vitamin E is found in a variety of tissues, being lipid-soluble, and taken up by the body in a wide variety of ways. The most prevalent form, ?-tocopherol, is involved in molecular, cellular, biochemical processes closely related to overall lipoprotein and lipid homeostasis. Ongoing research is believed to be "critical for manipulation of vitamin E homeostasis in a variety of oxidative stress-related disease conditions in humans."[2] One of these disease conditions is the ?-tocopherol role in the use by malaria parasites to protect themselves from the highly oxidative environment in erythrocytes.[3]
?-Tocopherol has three stereocenters, so it is a chiral molecule.[4] The eight stereoisomers of ?-tocopherol differ in the configuration of these stereocenters. RRR-?-tocopherol is the natural one.[5] The older name of RRR-?-tocopherol is d-?-tocopherol, but this d/l naming should be no longer used, because whether l-?-tocopherol should mean SSS enantiomer or the SRR diastereomer is not clear, from historical reasons. The SRR may be named 2-epi-?-tocopherol, the diastereomeric mixture of RRR-?-tocopherol and 2-epi-?-tocopherol may be called 2-ambo-?-tocopherol (formerly named dl-?-tocopherol). The mixture of all eight diastereomers is called all-rac-?-tocopherol[6]
One IU of tocopherol is defined as 2/3 milligram of RRR-?-tocopherol (formerly named d-?-tocopherol). 1 IU is also defined as 0.9 mg of an equal mix of the eight stereoisomers, which is a racemic mixture, all-rac-?-tocopheryl acetate. This mix of stereoisomers is often called dl-?-tocopheryl acetate.[7] Starting with May 2016, the IU unit is made obsolete, such that 1 mg of "Vitamin E" is 1 mg of d-alpha-tocopherol or 2 mg of dl-alpha-tocopherol.[8]