Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Α-Tocopherol: Difference between pages

{{lowercasetitle}}

{{Chembox

| verifiedrevid = 477319727

| Name = α-Tocopherol

| Reference = <ref>''Merck Index'', 11th Edition, '''9931'''.</ref>

| ImageFile = Tocopherol, alpha-.svg

| ImageSize = 300px

| ImageFile1 = Vitamin-E-from-xtal-3D-bs-17.png

| ImageSize1 = 300px

| ImageFile2 = Sample of alpha-tocopherol.jpg

| ImageSize2 = 300px

| PIN = (2''R'')-2,5,7,8-Tetramethyl-2-[(4''R'',8''R'')-4,8,12-trimethyltridecyl]-3,4-dihydro-2''H''-1-benzopyran-6-ol

| OtherNames =

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo = 59-02-9

}}

|Section2={{Chembox Properties

| Formula = C₂₉H₅₀O₂

| MolarMass = 430.71 g/mol

| Appearance = yellow-brown viscous liquid

| Density = 0.950 g/cm³

| MeltingPtC = 2.5 to 3.5

| BoilingPtC = 200 to 220

| BoilingPt_notes = at 0.1 mmHg

| Solubility = insoluble

| SolubleOther = soluble in alcohol, [[ether]], [[acetone]], oils

}}

|Section6={{Chembox Pharmacology

|Section7={{Chembox Hazards

| NFPA-H = 1

| NFPA-F = 1

| NFPA-R = 0

| MainHazards =

| FlashPt =

| AutoignitionPt =

}}

'''α-Tocopherol''' (''alpha''-tocopherol) is a type of [[vitamin E]]. Its [[E number]] is "E307". Vitamin E exists in eight different forms, four [[tocopherol]]s and four [[tocotrienol]]s. 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, α-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, α-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."<ref>{{cite journal | vauthors = Rigotti A | title = Absorption, transport, and tissue delivery of vitamin E | journal = Molecular Aspects of Medicine | volume = 28 | issue = 5–6 | pages = 423–36 | year = 2007 | pmid = 17320165 | doi = 10.1016/j.mam.2007.01.002 }}</ref> One of these disease conditions is the α-tocopherol role in the use by [[malaria]] parasites to protect themselves from the highly oxidative environment in [[erythrocytes]].<ref>{{cite journal | vauthors = Shichiri M, Ishida N, Hagihara Y, Yoshida Y, Kume A, Suzuki H | title = Probucol induces the generation of lipid peroxidation products in erythrocytes and plasma of male cynomolgus macaques | journal = Journal of Clinical Biochemistry and Nutrition | volume = 64 | issue = 2 | pages = 129–142| year = 2019 | pmid = 30936625 |pmc = 6436040 | doi = 10.3164/jcbn.18-7}}</ref>

== Stereoisomers ==

α-Tocopherol has three [[stereocenter]]s, so it is a [[Chirality (chemistry)|chiral]] molecule.<ref>{{cite journal | vauthors = Jensen SK, Lauridsen C | title = Alpha-tocopherol stereoisomers | journal = Vitamins and Hormones | volume = 76 | pages = 281–308 | year = 2007 | pmid = 17628178 | doi = 10.1016/S0083-6729(07)76010-7 | isbn = 9780123735928 }}</ref> The eight [[Stereoisomerism|stereoisomers]] of α-tocopherol differ in the configuration of these stereocenters. ''RRR''-α-tocopherol is the natural one.<ref>{{cite journal | vauthors = Brigelius-Flohé R, Traber MG | title = Vitamin E: function and metabolism | journal = FASEB Journal | volume = 13 | issue = 10 | pages = 1145–55 | date = July 1999 | pmid = 10385606 | doi = 10.1096/fasebj.13.10.1145 | s2cid = 7031925 | url = http://www.fasebj.org/cgi/pmidlookup?view=long&pmid=10385606 | doi-access = free }}</ref> The older name of ''RRR''-α-tocopherol is ''d''-α-tocopherol, but this ''d/l'' naming should no longer be used, because whether ''l''-α-tocopherol should mean ''SSS'' enantiomer or the ''SRR'' diastereomer is not clear, from historical reasons. The ''SRR'' may be named 2-''epi''-α-tocopherol, the diastereomeric mixture of ''RRR''-α-tocopherol and 2-''epi''-α-tocopherol may be called 2-''ambo''-α-tocopherol (formerly named ''dl''-α-tocopherol). The mixture of all eight diastereomers is called ''all''-''rac''-α-tocopherol.<ref name="IUPAC1">[https://web.archive.org/web/20201122071533/https://www.qmul.ac.uk/sbcs/iupac/misc/toc.html IUPAC Nomenclature of Tocopherols and Related Compounds], from https://www.degruyter.com/document/doi/10.1351/pac198254081507/pdf</ref>

One IU of tocopherol is defined as {{frac|2|3}} milligram of ''RRR''-α-tocopherol (formerly named ''d''-α-tocopherol). 1 IU is also defined as 0.9 mg of an equal mix of the eight stereoisomers, which is a [[racemic mixture]], [[tocopheryl acetate|''all''-''rac''-α-tocopheryl acetate]]. This mix of stereoisomers is often called ''dl''-α-tocopheryl acetate.<ref>{{cite web|archive-url=https://web.archive.org/web/20120219164132/http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/SR20_doc.pdf |archive-date=2012-02-19 |url=https://www.ars.usda.gov/ARSUserFiles/80400525/Data/SR20/SR20_doc.pdf |title=Composition of Foods Raw, Processed, Prepared USDA National Nutrient Database for Standard Reference, Release 20 |publisher=[[USDA]] |date=February 2008 |url-status=dead }}</ref> Starting with May 2016, the IU unit is made obsolete, such that 1&nbsp;mg of "Vitamin E" is 1&nbsp;mg of d-alpha-tocopherol or 2&nbsp;mg of dl-alpha-tocopherol.<ref name=NIH-Calc>{{cite web |title=Unit Conversions |url=https://dietarysupplementdatabase.usda.nih.gov/Conversions.php |publisher=[[National Institutes of Health]] |access-date=2018-11-21}}</ref>

<!-- already cited == See also ==

* [[Tocopherol]]

* [[Tocotrienol]]

-->

== References ==

{{Reflist}}

{{Vitamin}}

{{DEFAULTSORT:Tocopherol, Alpha-}}

[[Category:Vitamin E]]