Triacetin

Last updated

Contents

Triacetin [1]
Triacetin.svg
Triacetin 3D ball.png
Names
Systematic IUPAC name
Propane-1,2,3-triyl triacetate
Other names
  • Glycerol triacetate [2]
  • glycerin triacetate
  • 1,2,3-triacetylglycerol
  • 1,2,3-triacetoxypropane
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.002.775 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-051-9
E number E1518 (additional chemicals)
KEGG
PubChem CID
RTECS number
  • AK3675000
UNII
  • InChI=1S/C9H14O6/c1-6(10)13-4-9(15-8(3)12)5-14-7(2)11/h9H,4-5H2,1-3H3 Yes check.svgY
    Key: URAYPUMNDPQOKB-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C9H14O6/c1-6(10)13-4-9(15-8(3)12)5-14-7(2)11/h9H,4-5H2,1-3H3
    Key: URAYPUMNDPQOKB-UHFFFAOYAH
  • CC(=O)OC(COC(=O)C)COC(C)=O
Properties
C9H14O6
Molar mass 218.205 g·mol−1
AppearanceOily liquid
Density 1.155 g/cm3 [3]
Melting point −78 °C (−108 °F; 195 K)
at 760 mmHg [2]
Boiling point 259 °C (498 °F; 532 K)
at 760 mmHg [2]
6.1 g/100 mL [2]
Solubility Miscible in EtOH
Soluble in C6H6, (C2H5)2O, acetone [2]
Vapor pressure 0.051 Pa (11.09 °C)
0.267 Pa (25.12 °C)
2.08 Pa (45.05 °C) [4]
ln(P/Pa)=22.819-4493/T(K)-807000/T(K)²
1.4301 (20 °C) [2]
1.4294 (24.5 °C) [4]
Viscosity 23 cP (20 °C) [3]
Thermochemistry
389 J/mol·K [5]
Std molar
entropy
(S298)
458.3 J/mol·K [5]
−1330.8 kJ/mol [5]
4211.6 kJ/mol [5]
Hazards
NFPA 704 (fire diamond)
[3]
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
Flash point 138 °C (280 °F; 411 K) [3]
430 °C (806 °F; 703 K) [3]
Explosive limits 7.73% [3]
Lethal dose or concentration (LD, LC):
1100 mg/kg (mice, oral) [3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Triacetin is the organic compound with the formula C3H5(OCOCH3)3. It is classified as a triglyceride, i.e., the triester of glycerol with acetic acid. [6] It is a colorless, viscous, and odorless liquid with a high boiling point and a low melting point. It has a mild, sweet taste in concentrations lower than 500 ppm, but may appear bitter at higher concentrations. [7] It is one of the glycerine acetate compounds.

Uses

Triacetin is a common food additive, for instance as a solvent in flavorings, and for its humectant function, with E number E1518 and Australian approval code A1518. It is used as an excipient in pharmaceutical products, where it is used as a humectant, a plasticizer, and as a solvent. [8]

Potential uses

The plasticizing capabilities of triacetin have been utilized in the synthesis of a biodegradable phospholipid gel system for the dissemination of the cancer drug paclitaxel (PTX). [9] In the study, triacetin was combined with PTX, ethanol, a phospholipid and a medium chain triglyceride to form a gel-drug complex. This complex was then injected directly into the cancer cells of glioma-bearing mice. The gel slowly degraded and facilitated sustained release of PTX into the targeted glioma cells.

Triacetin can also be used as a fuel additive as an antiknock agent which can reduce engine knocking in gasoline, and to improve cold and viscosity properties of biodiesel. [10]

It has been considered as a possible source of food energy in artificial food regeneration systems on long space missions. It is believed to be safe to get over half of one's dietary energy from triacetin. [11]

Synthesis

Triacetin was first prepared in 1854 by the French chemist Marcellin Berthelot. [12] Triacetin was prepared in the 19th century from glycerol and acetic acid. [13]

Its synthesis from acetic anhydride and glycerol is simple and inexpensive.

3 (CH3CO)2O + 1 C3H5(OH)3 → 1 C3H5(OCOCH3)3 + 3 CH3CO2H

This synthesis has been conducted with catalytic sodium hydroxide and microwave irradiation to give a 99% yield of triacetin. [14] It has also been conducted with a cobalt(II) Salen complex catalyst supported by silicon dioxide and heated to 50 °C for 55 minutes to give a 99% yield of triacetin. [15]

Safety

The US Food and Drug Administration has approved it as Generally Recognized as Safe [16] food additive and included it in the database according to the opinion from the Select Committee On GRAS Substances (SCOGS). Triacetin is included in the SCOGS database since 1975. [17]

Triacetin was not toxic to animals in studies of exposure through repeated inhalation over a relatively short period. [18]

Related Research Articles

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

Sorbitol, less commonly known as glucitol, is a sugar alcohol with a sweet taste which the human body metabolizes slowly. It can be obtained by reduction of glucose, which changes the converted aldehyde group (−CHO) to a primary alcohol group (−CH2OH). Most sorbitol is made from potato starch, but it is also found in nature, for example in apples, pears, peaches, and prunes. It is converted to fructose by sorbitol-6-phosphate 2-dehydrogenase. Sorbitol is an isomer of mannitol, another sugar alcohol; the two differ only in the orientation of the hydroxyl group on carbon 2. While similar, the two sugar alcohols have very different sources in nature, melting points, and uses.

<span class="mw-page-title-main">Formic acid</span> Simplest carboxylic acid (HCOOH)

Formic acid, systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure H−C(=O)−O−H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Esters, salts and the anion derived from formic acid are called formates. Industrially, formic acid is produced from methanol.

<span class="mw-page-title-main">Glycerol</span> Chemical compound widely used in food and pharmaceuticals

Glycerol, also called glycerine or glycerin, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pharmaceutical formulations. Because of its three hydroxyl groups, glycerol is miscible with water and is hygroscopic in nature.

<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.

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

Dihydroxyacetone, also known as glycerone, is a simple saccharide with formula C
3
H
6
O
3
.

A humectant is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moisture in the food. Humectants are sometimes used as a component of antistatic coatings for plastics.

In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed acetate esters or simply acetates. Deacetylation is the opposite reaction, the removal of an acetyl group from a chemical compound.

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

Acrolein is the simplest unsaturated aldehyde. It is a colorless liquid with a foul and acrid aroma. The smell of burnt fat is caused by glycerol in the burning fat breaking down into acrolein. It is produced industrially from propene and mainly used as a biocide and a building block to other chemical compounds, such as the amino acid methionine.

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

Magnesium stearate is the chemical compound with the formula Mg(C
18
H
35
O
2
)
2
. It is a soap, consisting of salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Magnesium stearate is a white, water-insoluble powder. Its applications exploit its softness, insolubility in many solvents, and low toxicity. It is used as a release agent and as a component or lubricant in the production of pharmaceuticals and cosmetics.

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

Epichlorohydrin is an organochlorine compound and an epoxide. Despite its name, it is not a halohydrin. It is a colorless liquid with a pungent, garlic-like odor, moderately soluble in water, but miscible with most polar organic solvents. It is a chiral molecule generally existing as a racemic mixture of right-handed and left-handed enantiomers. Epichlorohydrin is a highly reactive electrophilic compound and is used in the production of glycerol, plastics, epoxy glues and resins, epoxy diluents and elastomers.

<span class="mw-page-title-main">Polyglycerol polyricinoleate</span> Emulsion used in food production

Polyglycerol polyricinoleate (PGPR), E476, is an emulsifier made from glycerol and fatty acids. In chocolate, compound chocolate and similar coatings, PGPR is mainly used with another substance like lecithin to reduce viscosity. It is used at low levels, and works by decreasing the friction between the solid particles in molten chocolate, reducing the yield stress so that it flows more easily, approaching the behaviour of a Newtonian fluid. It can also be used as an emulsifier in spreads and in salad dressings, or to improve the texture of baked goods. It is made up of a short chain of glycerol molecules connected by ether bonds, with ricinoleic acid side chains connected by ester bonds.

In organic chemistry, the acetoxy group, is a functional group with the formula −OCOCH3 and the structure −O−C(=O)−CH3. As the -oxy suffix implies, it differs from the acetyl group by the presence of an additional oxygen atom. The name acetoxy is the short form of acetyl-oxy.

<span class="mw-page-title-main">Bath salts</span> Bath water additives

Bath salts are water-soluble, pulverized minerals that are added to water to be used for bathing. It is said that these salts improve cleaning, enhance the enjoyment of bathing, and serve as a vehicle for cosmetic agents. Bath salts have been developed which mimic the properties of natural mineral baths or hot springs. Some bath salts contain glycerine so the product will act as an emollient, humectant, or lubricant. Fragrances and colors are often added to bath salts; the fragrances are used to increase the users' enjoyment of the bathing experience.

Lanthanide triflates are triflate salts of the lanthanides. These salts have been investigated for application in organic synthesis as Lewis acid catalysts. These catalysts function similarly to aluminium chloride or ferric chloride, but they are water-tolerant (stable in water). Commonly written as Ln(OTf)3·(H2O)9 the nine waters are bound to the lanthanide, and the triflates are counteranions, so more accurately lanthanide triflate nonahydrate is written as [Ln(H2O)9](OTf)3.

<span class="mw-page-title-main">Cellulose acetate phthalate</span> Chemical compound

Cellulose acetate phthalate (CAP), also known as cellacefate (INN) and cellulosi acetas phthalas, is a commonly used polymer phthalate in the formulation of pharmaceuticals, such as the enteric coating of tablets or capsules and for controlled release formulations. It is a cellulose polymer where about half of the hydroxyls are esterified with acetyls, a quarter are esterified with one or two carboxyls of a phthalic acid, and the remainder are unchanged. It is a hygroscopic white to off-white free-flowing powder, granules, or flakes. It is tasteless and odorless, though may have a weak odor of acetic acid. Its main use in pharmaceutics is with enteric formulations. It can be used together with other coating agents, e.g. ethyl cellulose. Cellulose acetate phthalate is commonly plasticized with diethyl phthalate, a hydrophobic compound, or triethyl citrate, a hydrophilic compound; other compatible plasticizers are various phthalates, triacetin, dibutyl tartrate, glycerol, propylene glycol, tripropionin, triacetin citrate, acetylated monoglycerides, etc.

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

Glycerine acetate is a mixture of esters produced from the esterification of glycerol (1) with acetic acid. This reaction produces five congeners:

<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. Acetic acid is also known as acetyl hydroxide (AcOH).

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

Glyceryl diacetate is a food additive with the E number E1517. This diglyceride is more generally known as diacetin. It is the diester of glycerol and acetylating agents, such as acetic acid and acetic anhydride. It is a colorless, viscous and odorless liquid with a high boiling point. Glycerol diacetate is typically a mixture of two isomers, 1,2-glyceryl diacetate and 1,3-glyceryl diacetate.

<span class="mw-page-title-main">Glycerol-1,2-carbonate</span> Organic chemical compound

Glycerol-1,2-carbonate is formally the cyclic ester of carbonic acid with glycerol and has aroused great interest as a possible product from the "waste materials" carbon dioxide CO2 and glycerol (especially from biodiesel production) with a wide range of applications.

References

  1. Merck Index (11th ed.). p. 9405.
  2. 1 2 3 4 5 6 Lide DR, ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN   978-1-4200-9084-0.
  3. 1 2 3 4 5 6 7 "MSDS of Triacetin". fishersci.ca. Fisher Scientific. Retrieved 2014-06-20.
  4. 1 2 Woodman AL, Adicoff A (1963). "Vapor Pressure of Tiracetin, Triethylene Glycol Dinitrate, and Metriol Trinitrate". Journal of Chemical & Engineering Data. 8 (2): 241–242. doi:10.1021/je60017a033.
  5. 1 2 3 4 Triacetin in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD)
  6. Kong P, Aroua MK, Daud WM, Lee HV, Cognet P, Pérès Y (2016). "Catalytic role of solid acid catalysts in glycerol acetylation for the production of bio-additives: a review". RSC Advances. 6 (73): 68885–68905. Bibcode:2016RSCAd...668885K. doi:10.1039/C6RA10686B. S2CID   102384754.
  7. Arctander S (1969). Perfume and Flavor Chemicals (II K - Z). Elizabeth, N.J.: Published by the Author. p. 2971. ISBN   978-0-931710-37-7.
  8. "Triacetin". drugtopics.modernmedicine.com. Advanstar Communications, Inc. Archived from the original on 2012-02-19. Retrieved 2014-06-20.
  9. Chen T, Gong T, Zhao T, Liu X, Fu Y, Zhang Z, et al. (August 2017). "Paclitaxel loaded phospholipid-based gel as a drug delivery system for local treatment of glioma". International Journal of Pharmaceutics. 528 (1–2): 127–132. doi:10.1016/j.ijpharm.2017.06.013. PMID   28596136.
  10. Gupta M, Kumar N (2012). "Scope and opportunities of using glycerol as an energy source". Renewable & Sustainable Energy Reviews. 16 (7): 4551–4556. Bibcode:2012RSERv..16.4551G. doi:10.1016/j.rser.2012.04.001.
  11. Shapira J, Mandel AD, Quattrone PD, Bell NL (1968). "Current Research On Regenerative Systems" (PDF). Life Sciences in Space Research. 7. Tokyo: Committee On Space Research, Eleventh Annual Meeting: 123–9. PMID   12197534 . Retrieved 2024-07-16.
  12. Berthelot M (1854). "Sur les combinaisons de le glycérine avec les acides et sur la synthèse des principes immédiats des graisses des animaux" [On the compounds of glycerin with acids and on the synthesis of immediate principles of animal fats]. Annales de Chimie et de Physique. 3rd series (in French). 41: 216–319. ; see "Triacétine", pp. 282–283.
  13. "Preparation of glyceryl triacetate". Journal of the Chemical Society, Abstracts. 38: 312. 1880. doi: 10.1039/CA8803800307 .
  14. Rajabi F, Saidi MR (2005). "A Cheap, Simple, and Versatile Method for Acetylation of Alcohols and Phenols and Selective Deprotection of Aromatic Acetates Under Solvent-Free Condition". Synthetic Communications. 35 (3): 483–491. doi:10.1081/SCC-200048988. ISSN   0039-7911. S2CID   96001761.
  15. Rajabi F (2009). "A heterogeneous cobalt(II) Salen complex as an efficient and reusable catalyst for acetylation of alcohols and phenols". Tetrahedron Letters. 50 (4): 395–397. doi:10.1016/j.tetlet.2008.11.024.
  16. "21 CFR § 184.1901 Listing of Specific Substances Affirmed as GRAS: Triacetin". eCFR.gov. FDA. 21 Feb 1989. Retrieved 25 Apr 2023.
  17. "Glycerin and Glycerides". www.fda.gov. U.S. Food and Drug Administration. Archived from the original on 2017-10-31. Retrieved 2014-06-20. Triacetin and two types of acetooleins have been found to be without toxic effects in long-term feeding tests in rats at levels that were several orders of magnitude greater than those to which consumers are exposed. Three types of acetostearins have been found to be without toxic effects in long-term feeding tests in rats at levels up to 5 g per kg per day. This contrasts with an estimated human consumption of a fraction of a milligram per kg per day. It is recognized that at an even higher feeding level (10 g per kg per day) male rats developed testicular atrophy and female rats, uterine discoloration. However, such a level which would amount to 50 g or more for an infant and 600 g for an adult per day, is vastly higher than would be possible in the consumption of foods to which acetostearins are added for functional purposes.
  18. Fiume MZ (2003). "Final report on the safety assessment of triacetin". International Journal of Toxicology. 22 Suppl 2 (3): 1–10. doi:10.1080/747398359. PMID   14555416.