Α-Tocopheryl acetate

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α-Tocopheryl acetate
Tocopheryl acetate.png
Tocopheryl acetate 3d structure.png
Names
Preferred IUPAC name
(2R)-2,5,7,8-Tetramethyl-2-[(4R,8R)-4,8,12-trimethyltridecyl]-3,4-dihydro-2H-1-benzopyran-6-yl acetate
Other names
α-Tocopherol acetate
Vitamin E acetate
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.369 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C31H52O3/c1-21(2)13-10-14-22(3)15-11-16-23(4)17-12-19-31(9)20-18-28-26(7)29(33-27(8)32)24(5)25(6)30(28)34-31/h21-23H,10-20H2,1-9H3/t22-,23-,31-/m1/s1 Yes check.svgY
    Key: ZAKOWWREFLAJOT-CEFNRUSXSA-N Yes check.svgY
  • InChI=1/C31H52O3/c1-21(2)13-10-14-22(3)15-11-16-23(4)17-12-19-31(9)20-18-28-26(7)29(33-27(8)32)24(5)25(6)30(28)34-31/h21-23H,10-20H2,1-9H3/t22-,23-,31-/m1/s1
    Key: ZAKOWWREFLAJOT-CEFNRUSXBQ
  • O=C(Oc2c(c(c1O[C@](CCc1c2C)(C)CCC[C@H](C)CCC[C@H](C)CCCC(C)C)C)C)C
Properties
C31H52O3
Molar mass 472.743 g/mol
Appearancepale yellow, viscous liquid [1]
Melting point –27.5 °C [1]
Boiling point 240 °C decays without boiling [2]
insoluble [1]
Solubility soluble in acetone, chloroform, diethyl ether; poorly soluble in ethanol [1]
Hazards
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

α-Tocopheryl acetate (alpha-tocopherol acetate), also known as vitamin E acetate, is a form of vitamin E with D-Alpha Tocpheryl Acetate as the natural form and DL-Alpha Tocopheryl Acetate as the synthetic form. DL-indicates the synthetic form where as D- indicates the natural form. It is the ester of acetic acid and α-tocopherol . [2]

The U.S. Centers for Disease Control and Prevention says that vitamin E acetate is a very strong culprit of concern in the 2019 outbreak of vaping-associated pulmonary injury (VAPI), [3] but there is not yet sufficient evidence to rule out contributions from other chemicals. [4] [5] Vaporization of this ester produces toxic pyrolysis products. [6]

Use in cosmetics

α-Tocopheryl acetate is often used in dermatological products such as skin creams. It is not oxidized and can penetrate through the skin to the living cells, where about 5% is converted to free tocopherol. Claims are made for beneficial antioxidant effects. [7] α-Tocopheryl acetate is used as an alternative to tocopherol itself because the phenolic hydroxyl group is blocked, providing a less acidic product with a longer shelf life. It is believed that the acetate is slowly hydrolyzed after it is absorbed into the skin, regenerating tocopherol and providing protection against the sun's ultraviolet rays. [8] Tocopheryl acetate was first synthesized in 1963 by workers at Hoffmann-La Roche. [9]

Although there is widespread use of tocopheryl acetate as a topical medication, with claims for improved wound healing and reduced scar tissue, [10] reviews have repeatedly concluded that there is insufficient evidence to support these claims. [11] [12] There are reports of vitamin E-induced allergic contact dermatitis from use of vitamin E derivatives such as tocopheryl linoleate and tocopherol acetate in skin care products. Incidence is low despite widespread use. [13]

Misuse

Ingredient in vape liquids

On September 5, 2019, the United States Food and Drug Administration (US FDA) announced that 10 out of 18, or 56% of the samples of vape liquids sent in by states, linked to the recent vaping-related lung disease outbreak in the United States, tested positive for vitamin E acetate [14] which had been used as a thickening agent by illicit THC vape cartridge manufacturers. [15] On November 8, 2019, the Centers for Disease Control and Prevention (CDC) identified vitamin E acetate as a very strong culprit of concern in the vaping-related illnesses, but has not ruled out other chemicals or toxicants as possible causes. [3] The CDC's findings were based on fluid samples from the lungs of 29 patients with vaping-associated pulmonary injury, which provided direct evidence of vitamin E acetate at the primary site of injury in all the 29 lung fluid samples tested. [3] Research suggests when vitamin E acetate is inhaled, it may interfere with normal lung functioning. [5] A 2020 study found that vaporizing vitamin E acetate produced carcinogenic alkenes and benzene, but also exceptionally toxic ketene gas, which may be a contributing factor to the pulmonary injuries. [6]

Chemistry

At room temperature, α-tocopheryl acetate is a fat-soluble liquid. It has 3 chiral centers and thus 8 stereoisomers. It is made by esterifying α-tocopherol with acetic acid. 2R,4R,8R-isomer, also known as RRR-α-tocopheryl acetate, is the most common isomer used for various purposes. This is because α-tocopherol occurs in nature primarily as RRR-α-tocopherol. [2]

α-Tocopherol acetate does not boil at atmospheric pressure and begins to degrade at 240 °C. [2] It can be vacuum distilled: it boils at 184 °C at 0.01  mmHg, at 194 °C (0.025 mmHg) and at 224 °C (0.3 mmHg). In practice, it is not degraded notably by air, visible light or UV-radiation. It has a refractive index of 1.4950–1.4972 at 20 °C. [1]

α-Tocopherol acetate is hydrolyzed to α-tocopherol and acetic acid under suitable conditions or when ingested by people. [2]

Related Research Articles

Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E, can cause nerve problems. Vitamin E is a fat-soluble antioxidant which may help protect cell membranes from reactive oxygen species. Worldwide, government organizations recommend adults consume in the range of 3 to 15 mg per day. As of 2016, consumption was below recommendations according to a worldwide summary of more than one hundred studies that reported a median dietary intake of 6.2 mg per day for alpha-tocopherol. Foods rich in vitamin E include seeds and nuts, seed oils, peanut butter, and vitamin E-fortified foods, such as margarine.

Tocopherols are a class of organic compounds comprising various methylated phenols, many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named tocopherol, from Greek τόκοςtókos 'birth' and φέρεινphérein 'to bear or carry', that is 'to carry a pregnancy', with the ending -ol signifying its status as a chemical alcohol.

<span class="mw-page-title-main">Dermatitis</span> Inflammatory disease of the skin

Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can vary from small to covering the entire body. Dermatitis is often called eczema, and the difference between those terms is not standardized.

<span class="mw-page-title-main">Corticosteroid</span> Class of steroid hormones

Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.

<span class="mw-page-title-main">Propylene glycol</span> Chemical compound

Propylene glycol (IUPAC name: propane-1,2-diol) is a viscous, colorless liquid. It is almost odorless and has a faintly sweet taste. Its chemical formula is CH3CH(OH)CH2OH. As it contains two alcohol groups, it is classed as a diol. An aliphatic diol may also be called a glycol. It is miscible with a broad range of solvents, including water, acetone, and chloroform. In general, glycols are non-irritating and have very low volatility.

The vitamin E family comprises four tocotrienols and four tocopherols. The critical chemical structural difference between tocotrienols and tocopherols is that tocotrienols have unsaturated isoprenoid side chains with three carbon-carbon double bonds versus saturated side chains for tocopherols.

Phytol is an acyclic hydrogenated diterpene alcohol that is used as a precursor for the manufacture of synthetic forms of vitamin E and vitamin K1, as well as in the fragrance industry. Its other commercial uses include cosmetics, shampoos, toilet soaps, and detergents, as well as in some cannabis distillates as a diluent or for flavoring. Its worldwide use has been estimated to be approximately 0.1–1.0 metric tons per year.

α-Tocopherol Chemical compound

α-Tocopherol (alpha-tocopherol) is a type of vitamin E. Its E number is "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, α-tocopherol is preferentially absorbed and accumulated in humans.

Rose hip seed oil is a pressed seed oil, extracted from the seeds of the wild rose bush Rosa rubiginosa in the southern Andes. Rosehip seed oil can also be extracted from Rosa canina, a wild rose species native to Europe, northwest Africa, and western Asia. The fruits of the rosehip have been used in folk medicine for a long time. Rosehips have prophylactic and therapeutic actions against the common cold, infectious diseases, gastrointestinal disorders, urinary tract diseases, and inflammatory diseases.

<span class="mw-page-title-main">THC-O-acetate</span> Acetate ester of tetrahydrocannabinol (THC)

THC-O-acetate is the acetate ester of THC. The term THC-O-acetate and its variations are commonly used for two types of the substance, dependent on which cannabinoid it is synthesized from. The difference between Δ8-THC and Δ9-THC is bond placement on the cyclohexene ring.

<span class="mw-page-title-main">Ethenone</span> Organic compound with the formula H2C=C=O

In organic chemistry, ethenone is the formal name for ketene, an organic compound with formula C2H2O or H2C=C=O. It is the simplest member of the ketene class. It is an important reagent for acetylations.

Vitamins occur in a variety of related forms known as vitamers. A vitamer of a particular vitamin is one of several related compounds that performs the functions of said vitamin and prevents the symptoms of deficiency of said vitamin.

<span class="mw-page-title-main">Duroquinone</span> Chemical compound

Duroquinone is an organic oxidant (C6(CH3)4O2). It is related to 1,4-benzoquinone by replacement of four H centres with methyl (Me) groups. The C10O2 core of this molecule is planar with two pairs of C=O and C=C bonds.

<span class="mw-page-title-main">Acetic acid</span> Colorless and faint organic acid found in vinegar

Acetic acid, systematically named ethanoic acid, is an acidic, colourless liquid and organic compound with the chemical formula CH3COOH. Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. It has been used, as a component of vinegar, throughout history from at least the third century BC.

<span class="mw-page-title-main">Hash oil</span> Oleoresin obtained by the extraction of cannabis or hashish

Hash oil or cannabis oil is an oleoresin obtained by the extraction of cannabis or hashish. It is a cannabis concentrate containing many of its resins and terpenes – in particular, tetrahydrocannabinol (THC), cannabidiol (CBD), and other cannabinoids. Hash oil is usually consumed by smoking, vaporizing or eating. Preparations of hash oil may be solid or semi-liquid colloids depending on both production method and temperature and are usually identified by their appearance or characteristics. Color most commonly ranges from transparent golden or light brown, to tan or black. There are various extraction methods, most involving a solvent, such as butane or ethanol.

<span class="mw-page-title-main">Aluminium diacetate</span> Chemical compound

Aluminium diacetate, also known as basic aluminium acetate, is a white powder with the chemical formula C4H7AlO5. It is one of a number of aluminium acetates and can be prepared in a reaction of sodium aluminate (NaAlO2) with acetic acid.

The health effects of electronic cigarettes (e-cigarettes) include a range of potential risks such as exposure to toxic chemicals, the possibility of increased likelihood of respiratory and cardiovascular diseases, and concerns about their possible role in cancer development. Upon their introduction, there were marketing claims that they were a safer alternative to traditional tobacco products.

α-Tocopheryl palmitate Chemical compound

α-Tocopheryl palmitate is the palmitate ester of α-tocopherol and is a form of vitamin E. Related compounds include α-tocopheryl acetate and α-tocopheryl succinate.

<span class="mw-page-title-main">2019–2020 vaping lung illness outbreak</span> Outbreak of vaping-associated pulmonary injury

An outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) started in 2019 among users of illegal, unregulated cannabis vaping products, almost exclusively in the United States. The first cases of this particular outbreak were identified in Illinois and Wisconsin in April 2019; as of 18 February 2020, a total of 2,807 hospitalized cases, including 68 deaths, have been confirmed. According to the U.S. Centers for Disease Control (CDC), "Vitamin E acetate is strongly linked to the EVALI outbreak...Evidence is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC or non-THC products, in some of the reported EVALI cases".

Vaping-associated pulmonary injury (VAPI), also known as vaping-associated lung injury (VALI) or e-cigarette, or vaping, product use associated lung injury (E/VALI), is an umbrella term, used to describe lung diseases associated with the use of vaping products that can be severe and life-threatening. Symptoms can initially mimic common pulmonary diagnoses, such as pneumonia, but sufferers typically do not respond to antibiotic therapy. Differential diagnoses have overlapping features with VAPI, including COVID-19. According to a systematic review article, "Initial case reports of vaping-related lung injury date back to 2012, but the ongoing outbreak of EVALI began in the summer of 2019." According to an article in the Radiological Society of North America news published in March 2022, EVALI cases continue to be diagnosed. “EVALI has by no means disappeared,” Dr. Kligerman said. “We continue to see numerous cases, even during the pandemic, many of which are initially misdiagnosed as COVID-19.”

References

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  2. 1 2 3 4 5 "Safety assessment of the substance α-tocopherol acetate for use in food contact materials". EFSA Journal. 14 (3): 4412. 2016. doi: 10.2903/j.efsa.2016.4412 .
  3. 1 2 3 "Transcript of CDC Telebriefing: Update on Lung Injury Associated with E-cigarette Use, or Vaping". Centers for Disease Control and Prevention. November 8, 2019.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  4. Feldman R, Meiman J, Stanton M, Gummin DD (June 2020). "Culprit or correlate? An application of the Bradford Hill criteria to Vitamin E acetate". Archives of Toxicology. 94 (6): 2249–2254. doi:10.1007/s00204-020-02770-x. ISSN   1432-0738. PMID   32451600. S2CID   218878143.
  5. 1 2 "Outbreak of Lung Injury Associated with E-Cigarette Use, or Vaping". Centers for Disease Control and Prevention. November 8, 2019.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  6. 1 2 Wu D, O'Shea DF (March 24, 2020). "Potential for release of pulmonary toxic ketene from vaping pyrolysis of vitamin E acetate". Proceedings of the National Academy of Sciences of the United States of America. 117 (12): 6349–6355. Bibcode:2020PNAS..117.6349W. doi: 10.1073/pnas.1920925117 . PMC   7104367 . PMID   32156732.
  7. Linus Pauling Institute Research Report: All About E at the Wayback Machine (archived February 23, 2015)
  8. Beijersbergen van Henegouwen G, Junginger H, de Vries H (1995). "Hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the skin and its UV protecting activity (an in vivo study with the rat)". J Photochem Photobiol B. 29 (1): 45–51. doi:10.1016/1011-1344(95)90251-1. PMID   7472802.
  9. Mayer H, Schudel P, Rüegg R, Isler O (1963). "Über die Chemie des Vitamins E. 3. Mitteilung. Die Totalsynthese von (2R, 4′R, 8′R)- und (2S, 4′R, 8′R)-α-Tocopherol". Helvetica Chimica Acta. 46 (2): 650–671. doi:10.1002/hlca.19630460225. ISSN   0018-019X.
  10. Panin G, Strumia R, Ursini F (2004). "Topical alpha-tocopherol acetate in the bulk phase: eight years of experience in skin treatment" (PDF). Ann. N. Y. Acad. Sci. 1031 (1): 443–447. Bibcode:2004NYASA1031..443P. doi:10.1196/annals.1331.069. PMID   15753192. S2CID   45771699 .
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