Tocopheryl acetate
| Structural formula | |||||||||
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| ( R , R , R ) -isomer (structural formula of one of eight isomers) | |||||||||
| General | |||||||||
| Common name | Vitamin E acetate | ||||||||
| other names |
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| Molecular formula | C 31 H 52 O 3 | ||||||||
| CAS number |
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| PubChem | 86472 | ||||||||
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| Brief description |
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| Occurrence | only synthetic | ||||||||
| physiology | |||||||||
| function | antioxidant | ||||||||
| Daily need | Vitamin E equivalent | ||||||||
| Consequences in case of deficiency | see vitamin E. | ||||||||
| Overdose | > 300 mg / day | ||||||||
| properties | |||||||||
| Molar mass | 472.76 g mol −1 | ||||||||
| Physical state |
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| density | 0.9533 g cm −3 | ||||||||
| Melting point |
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| boiling point |
Bp. 184 ° C at 0.01 mmHg (racemate) |
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| solubility |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||
α -Tocopheryl acetate ( vitamin E acetate ) is a synthetic vitamin E derivative . In the body it is converted to vitamin E and is therefore one of the provitamins .
structure
α-tocopheryl acetate is a Essigsäureester of Vitamin E . It contains three stereocenters , so there are eight stereoisomeric α-tocopheryl acetates. The commercially available α-tocopheryl acetate is a mixture of these isomers. This is usually referred to as all-rac -α-tocopheryl acetate, also outdated as DL - α -tocopheryl acetate .
In addition, there are three other derivatives (β, γ and δ) that differ in the methylation of the chroman ring . There are also eight stereoisomers of β-, γ- and δ-tocopheryl acetate.
| Structure of the ( RRR ) isomers | ||
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-Tocopheryl_Acetate_Structural_Formulae_V.1.svg)
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| Surname | R 1 | R 2 |
| α-tocopheryl acetate | CH 3 | CH 3 |
| β-tocopheryl acetate | CH 3 | H |
| γ-tocopheryl acetate | H | CH 3 |
| δ-tocopheryl acetate | H | H |
Manufacturing
The production of vitamin E acetate is a multi-step process. A possible synthetic chain based on 2,3,6-trimethylphenol is:
- Sulphonation of 2,3,6-trimethylphenol (TMP) (solid) with sulfuric acid to 2,3,5-trimethyl-4-hydroxybenzenesulphonic acid (solid)
- Oxidation with manganese dioxide to 2,3,6-trimethyl- 1,4 - benzoquinone (TMQ), liquid
- Reduction z. B. with sodium dithionite or hydrazine to 2,3,5-trimethyl-1,4- hydroquinone , in powder form
- Condensation with isophytol to form DL - α -tocopherol
- Acetylation with acetic anhydride to DL - α- tocopheryl acetate - the acetylation is necessary because DL - α- tocopherol is not resistant to oxidation.
- Vacuum distillation for cleaning - the product can thus easily comply with the degree of purity in accordance with the provisions of the German Additives Traffic Ordinance and the strict pharmaceutical regulations.
Vitamin E acetate is u. a. manufactured by BASF , E. Merck (India) and DSM Nutritional Products .
The synthetic provitamin E is also often used as a feed additive and an additive for cosmetics.
properties
α-Tocopheryl acetate is an oily, odorless, water-insoluble liquid. Since it is synthesized with a high degree of purity, it can also be used for the production of medicines. In contrast to natural vitamin E, α-tocopheryl acetate is relatively stable and can be stored for a longer period of time.
pharmacology
The provitamin itself has no effect as a fat-soluble antioxidant . The hydroxyl group required for this task is esterified in tocopheryl acetate and is therefore inaccessible. In the body, however, it is quickly converted into the active vitamin E by esterases . This also happens when it is absorbed through the skin. Here, however, the type of preparation plays a decisive role: with aqueous preparations, up to 50% can be absorbed, with oily preparations only less than 5%, where it can be converted into vitamin E.
In the USA in 2019, tocopherol acetate was added en masse in exclusively illegal cannabis products for e-cigarettes (so-called e-joints) as a blending agent and caused severe lung damage in a number of cases when inhaled.
Analytics
For a reliable qualitative and quantitative determination of tocopheryl acetate may for adequate sample preparation the gas chromatography or thin-layer chromatography may be used.
literature
- Jean-Marc Zingg: Molecular and cellular activities of vitamin E analogues . In: Mini-Rev Med Chem . , 7 (5), 2007, pp. 543-558, PMID 17504191 , doi: 10.2174 / 138955707780619608 .
Individual evidence
- ↑ a b c d e f g Michael Ash, Irene Ash: Handbook of preservatives. Synapse Information Resources, 2004, ISBN 1-890595-66-7 , p. 569.
- ^ A b David R. Lide: CRC Handbook of Chemistry and Physics . 87th edition, CRC Press, 2006, ISBN 0-8493-0487-3 , chap. 3, p. 520.
- ↑ Data sheet Vitamin E acetate from Sigma-Aldrich , accessed on April 24, 2011 ( PDF ).
- ↑ a b Entry on tocopheryl acetate in the ChemIDplus database of the United States National Library of Medicine (NLM), accessed on May 14, 2017.
- ↑ a b Gekkan Yakuji. ( Pharmaceuticals Monthly. ) Vol. 9, Pg. 759, 1967.
- ↑ Data sheets for evaluating the effectiveness of active ingredients in cosmetic products - Vitamin E (PDF; 148 kB), Lebensmittelchemische Gesellschaft.
- ^ New York State Department of Health Announces Update on Investigation into Vaping-Associated Pulmonary Illnesses. New York State Department of Health press release, September 5, 2019 (accessed November 10, 2019)
- ↑ W. Wachs, H.-U. Melchert: A new method for the quantitative determination of tocopherols in vegetable oils . In: Deutsche Lebensmittel-Rundschau , 67 (7), 1971, pp. 221-225.
- ↑ Trevithick JR, Mitton KP: Topical application and uptake of vitamin E acetate by the skin and conversion to free vitamin E . In: Biochem Mol Biol Int. , 1993 Dec; 31 (5), pp. 869-878, PMID 8136705 .
