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IUPAC name 3-phenylprop-2-enyl acetate | |
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3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.002.838 |
EC Number |
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KEGG | |
PubChem CID | |
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UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C11H12O2 | |
Molar mass | 176.215 g·mol−1 |
Appearance | Colorless liquid |
Odor | Sweet, floral, balsamic odor [3] |
Density | 1.057 g/mL [4] |
Boiling point | 265 °C (509 °F; 538 K) [3] |
212.3 mg/L [1] | |
log P | 2.85 [5] [6] |
Vapor pressure | 0.008 mm Hg (20°C) [1] |
Refractive index (nD) | 1.539 - 1.543 [3] |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | Causes eye irritation, may cause an allergic skin reaction [7] |
GHS labelling: | |
[7] | |
Warning [7] | |
H317, H319 [7] | |
P261, P264, P272, P280, P302+P352, P305+P351+P338, P321, P333+P313, P337+P313, P363, P501 [7] | |
NFPA 704 (fire diamond) | |
Flash point | 103–113 °C (217–235 °F; 376–386 K) [3] [8] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Cinnamyl acetate (3-phenylprop-2-enyl acetate) is a chemical compound of the cinnamyl ester family, in which the variable R group is substituted by a methyl group. As a result of the non-aromatic carbon-carbon double bond, cinnamyl acetate can exist in a Z and an E configuration: [9]
Cinnamyl acetate naturally occurs in fresh bark of cinnamon (Cinnamomum zeylanicum Blume and other Cinnamomum species), with concentrations of 2,800–51,000 ppm. [10] [5]
Cinnamyl acetate is used as a flavour ester in for example bread and animal feed and has a sweet floral-fruity fragrance. [6] [11] [12] Moreover, it is used in several cosmetics, some toiletries but also in non-cosmetic products, for example detergents. [9]
Cinnamyl acetate, used in fragrances and as flavour ingredient, has been discussed by several institutions. In 1965, the compound was annotated as 'Generally Recognized as Safe as a flavor ingredient’ by the Flavor and Extract Manufacturers" Association (FEMA). The association determined the average maximum use levels in several products that were considered to be safe: [13]
Beverages | Ice cream, ices, etc. | Candy | Baked goods | Chewing gum |
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2.7 ppm | 6.5 ppm | 16 ppm | 11 ppm | 8.7 ppm |
The European Parliament registered cinnamyl acetate as both a flavouring substance and a cosmetic compound in 1996. [14] [15] The Joint (FAO/WHO) Expert Committee on Food Additives (JECFA) described in 2000 that “the substance does not present a safety concern at current levels of intake when used as a flavouring agent”. [1] In 2009, the EFSA Panel on Food Contact Materials, Enzyme, Flavourings and Processing Aids (CEF) concluded that cinnamyl acetate does not give rise to safety concerns when used as flavour ingredient in food. [6] Cinnamyl acetate is also permitted by the U.S. Food & Drug administration for use as flavouring agent in food if the minimum quantity needed for its effect is used. [16]
Estimates of the average annual production and daily intake of cinnamyl acetate as flavouring agent are reported by the WHO. According to this report, the annual volume of production in Europe is 1498 kg, and in the USA 2255 kg. The daily intake per person in Europe is estimated to be 210 μg, and in the USA 300 μg. Per kg body weight the daily intake is estimated for Europeans to be 4 μg/kg and for Americans to be 5 μg/kg. [17]
Since cinnamyl acetate is naturally occurring in plants, it can be extracted and purified to obtain the compound. However, this has a low yield and therefore the production costs are high. The use of chemical methods can offer more efficient strategies to produce cinnamyl acetate. [10]
There are multiple ways to synthesize cinnamyl acetate 2. One way is the synthesis from cinnamyl alcohol 1 and vinyl acetate. This reaction is catalyzed by the enzyme triacylglycerol ester hydrolase, which is a lipase that is very specific towards the ester bond. The byproduct of this reaction is acetaldehyde. The reaction equation for this reaction is: [18]
Since acetaldehyde has an unfavourable deactivating effect on the lipase used in the synthesis, ethyl acetate can be used as reactant instead of vinyl acetate. In this transesterification reaction cinnamyl alcohol 1 reacts with ethyl acetate to form cinnamyl acetate 2 and ethanol. This synthesis requires the lipase Novozym 435, and is performed in a solvent-free system. The reaction is as follows: [12]
Cinnamyl acetate 2 can also be synthesized via a non-enzymatic reaction. An example of such a reaction is one with the use of cinnamyl bromide 3 and sodium acetate as reactants. Since these compounds are immiscible substrates, solid-liquid phase transfer catalysis (PTC) can be used, using quaternary ammonium bromide as a phase transfer catalyst. This is shown in the following reaction: [19]
Besides these three examples, there are many more ways to synthesize cinnamyl acetate.
The addition reaction of dinitrogen trioxide to cinnamyl acetate produces an intermediate in the synthesis of chloramphenicol. [20]
Cinnamyl acetate belongs to the group of cinnamyl derivatives. In general, these cinnamyl derivatives are absorbed from the gut very quickly, after which they are metabolized and excreted as polar metabolites in the urine or feces within 24 hours. [5] [21]
Within the cinnamyl derivatives, cinnamyl acetate belongs to the group of cinnamyl esters. After absorption from the gut, this group of compounds is first hydrolyzed to cinnamyl alcohol by carboxylesterases. Carboxylesterases are a group of enzymes. The most important enzymes within this group are the A-esterases. These are present in most body tissues, but they are prevalent in the hepatocytes. Subsequently, the cinnamyl alcohol is oxidized which leads to the formation of cinnamaldehyde. This reaction is catalyzed by human NAD+-dependent alcohol dehydrogenase. Now, there are two routes for the further biotransformation of cinnamaldehyde. The minor route of biotransformation is the S-glutathionylation. The major route, however, is the conversion of cinnamaldehyde into cinnamic acid by the enzyme aldehyde dehydrogenase. Next, the cinnamic acid is transformed into cinnamoyl CoA which is again converted to either cinnamoylglycine by N-acyl transferase or to benzoyl CoA through β-oxidation, the latter being the major route. Intermediate metabolites in the β-oxidation pathway can be converted to 3-hydroxy-3-phenylpropionic acid and acetophenone, which can be excreted via the urine. However, the conversions of these intermediate metabolites are minor routes. Finally, the benzoyl CoA is conjugated with glycine under formation of hippuric acid or it is hydrolyzed generating free benzoic acid. This can be excreted via the urine directly or after glucuronidation. Hippuric acid, which is the major metabolite, is also excreted via the urine. [5] [21] [6]
Since cinnamyl acetate is used as both a fragrance material and a food flavouring ingredient, dermal and oral exposure are considered to be the major routes of absorption. The dermal systematic exposure of cinnamyl acetate via cosmetic products is estimated to be 0.0115 mg/kg body weight/day. [5]
Several experiments using animals were conducted in the past to assess the toxicity of cinnamyl acetate. In one experiment, the oral toxicity was tested in rats. The rats received oral doses of cinnamyl acetate and the LD50 was found to be 3.3 g/kg. During the experiment, symptoms as slow respiration and coarse tremors were observed for high doses. [1] Other experiments showed LD50 values of 4.750 g/kg for oral administration in mice and guinea pigs. Also, the LD50 value for intraperitoneal administration was investigated and found to be 1.200 g/kg. [22]
Furthermore, studies on the dermal toxicity were performed. Experiments on rabbits resulted in an LD50 of more than 5.0 g/kg, but no clinical effects were observed. Moreover, the level of skin irritation in swines was tested via a 48-h patch test. In this study, 0.05 g of cinnamyl acetate was applied and no irritation was observed. Another two experiments examined the skin irritation caused by 0.1 mL cinnamyl acetate on guinea pigs and rabbits via a direct application on the skin (open application). Mild to moderate irritation was observed in these experiments. [1]
A NOAEL for oral administration of 275 mg/kg body weight/day was determined from toxicological data by the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP). [6]
Besides these experiments on animals, some human studies were executed. A 48-h closed patch test on five healthy, male volunteers was performed using 5% cinnamyl acetate in petrolatum. In this study, no irritation was observed. Mild irritation was observed in another 48-h patch test on fifty male volunteers using 32% cinnamyl acetate in acetone. Finally, a human study on skin sensitization was executed on 25 healthy, male volunteers. In this experiment a maximization test (48-h patch) was done using 5% cinnamyl acetate in petrolatum. Skin sensitization reactions were not observed. [1]
Moreover, standard Draize tests were used to assess the dermal toxicity in humans, guinea pigs and rabbits. This resulted in mild skin irritation for doses of 16 mg per 48 hours for humans and for doses of 100 mg per 24 hours for guinea pigs. Moderate skin irritation was observed for rabbits exposed to doses of 100 mg per 24 hours. [22]
Lastly, the potential of cinnamyl acetate to cause sister chromatid exchanges was tested using Chinese Hamster Ovary Cells. This was done because it was found that another component of plant essence and cinnamyl derivative, cinnamaldehyde, increased the frequency of sister chromatid exchanges induced by mitomycin C. However, the result of this test proved that cinnamyl acetate does not cause sister chromatid exchange due to the absence of an alpha-beta unsaturated carbonyl group. [23]
Cinnamyl acetate is found in the leaf oils of the Cinnamomum osmophloeum tree, which grows in central and northern Taiwan. It is found that these oils have antibacterial, antimildew, antitermite, antimite, antifungal and anti-inflammatory activities. Furthermore, the oils show mosquito larvicidal activity against Aedes aegypti and Aedes albopictus larvae. However, cinnamyl acetate serves only a minor role in these activities. [24] [25] [26] [27]
Moreover, cinnamyl acetate has a repellent effect on Anopheles gambiae , and is therefore useful to protect against these insects. [28]
Benzoic acid is a white solid organic compound with the formula C6H5COOH, whose structure consists of a benzene ring with a carboxyl substituent. The benzoyl group is often abbreviated "Bz", thus benzoic acid is also denoted as BzOH, since the benzoyl group has the formula –C6H5CO. It is the simplest aromatic carboxylic acid. The name is derived from gum benzoin, which was for a long time its only source.
In chemistry, an ester is a compound derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.
Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. Strong acids catalyze the reaction by donating a proton to the carbonyl group, thus making it a more potent electrophile. Bases catalyze the reaction by removing a proton from the alcohol, thus making it more nucleophilic. The reaction can also be accomplished with the help of other enzymes, particularly lipases.
Cinnamaldehyde is an organic compound with the formula or C6H5CH=CHCHO. Occurring naturally as predominantly the trans (E) isomer, it gives cinnamon its flavor and odor. It is a phenylpropanoid that is naturally synthesized by the shikimate pathway. This pale yellow, viscous liquid occurs in the bark of cinnamon trees and other species of the genus Cinnamomum. The essential oil of cinnamon bark is about 90% cinnamaldehyde. Cinnamaldehyde decomposes to styrene because of oxidation as a result of bad storage or transport conditions. Styrene especially forms in high humidity and high temperatures. This is the reason why cinnamon contains small amounts of styrene.
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions of transesterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols. The alcohols used should be of low molecular weight. Ethanol is the most used because of its low cost, however, greater conversions into biodiesel can be reached using methanol. Although the transesterification reaction can be catalyzed by either acids or bases, the base-catalyzed reaction is more common. This path has lower reaction times and catalyst cost than those acid catalysis. However, alkaline catalysis has the disadvantage of high sensitivity to both water and free fatty acids present in the oils. August 10 is international biodiesel day
Benzyl alcohol (also known as α-cresol) is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful as a solvent for its polarity, low toxicity, and low vapor pressure. Benzyl alcohol has moderate solubility in water (4 g/100 mL) and is miscible in alcohols and diethyl ether. The anion produced by deprotonation of the alcohol group is known as benzylate or benzyloxide.
Cinnamic acid is an organic compound with the formula C6H5-CH=CH-COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.
Ethyl acetate is the organic compound with the formula CH3CO2CH2CH3, simplified to C4H8O2. This colorless liquid has a characteristic sweet smell and is used in glues, nail polish removers, and in the decaffeination process of tea and coffee. Ethyl acetate is the ester of ethanol and acetic acid; it is manufactured on a large scale for use as a solvent.
Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, basil and bay leaf. It is present in concentrations of 80–90% in clove bud oil and at 82–88% in clove leaf oil. Eugenol has a pleasant, spicy, clove-like scent. The name is derived from Eugenia caryophyllata, the former Linnean nomenclature term for cloves. The currently accepted name is Syzygium aromaticum.
Vinyl acetate is an organic compound with the formula CH3CO2CH=CH2. This colorless liquid is the precursor to polyvinyl acetate, ethene-vinyl acetate copolymers, polyvinyl alcohol, and other important industrial polymers.
The phenylpropanoids are a diverse family of organic compounds that are synthesized by plants from the amino acids phenylalanine and tyrosine. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of coumaric acid, which is the central intermediate in phenylpropanoid biosynthesis. From 4-coumaroyl-CoA emanates the biosynthesis of myriad natural products including lignols, flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and phenylpropanoids. The coumaroyl component is produced from cinnamic acid.
1-Butanol, also known as butan-1-ol or n-butanol, is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of 1-butanol are isobutanol, butan-2-ol and tert-butanol. The unmodified term butanol usually refers to the straight chain isomer.
Cinnamyl alcohol or styron is an organic compound that is found in esterified form in storax, Balsam of Peru, and cinnamon leaves. It forms a white crystalline solid when pure, or a yellow oil when even slightly impure. It can be produced by the hydrolysis of storax.
Benzyl salicylate is a salicylic acid benzyl ester, a chemical compound most frequently used in cosmetics as a fragrance additive or UV light absorber. It appears as an almost colorless liquid with a mild odor described as "very faint, sweet-floral, slightly balsamic" by some, while others smell nothing at all. There is debate whether the odour is caused solely by impurities or a genetic predisposition. It occurs naturally in a variety of plants and plant extracts and is widely used in blends of fragrance materials.
Cinnamomum osmophloeum, commonly known as pseudocinnamomum or indigenous cinnamon, is a medium-sized evergreen tree in the genus Cinnamomum. It is native to broad-leaved forests of central and northern Taiwan.
Rosavin are a family of cinnamyl mono- and diglycosides that are key ingredients of Rhodiola rosea L.,. R. rosea is an important medicinal plant commonly used throughout Europe, Asia, and North America, that has been recognized as a botanical adaptogen by the European Medicines Agency. Rosavin production is specific to R. rosea and R. sachalinenis, and the biosynthesis of these glycosides occurs spontaneously in Rhodiola roots and rhizomes. The production of rosavins increases in plants as they get older, and the amount of the cinnamyl alcohol glycosides depends on the place of origin of the plant.
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.
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 and trace elements.
4-Methylcyclohexanemethanol (MCHM, systematic name 4-methylcyclohexylmethanol) is an organic compound with the formula CH3C6H10CH2OH. Classified as a saturated higher alicyclic primary alcohol. Both cis and trans isomers exist, depending on the relative positions of the methyl (CH3) and hydroxymethyl (CH2OH) groups on the cyclohexane ring. Commercial samples of MCHM consists of a mixture of these isomers as well as other components that vary with the supplier.
Benzyl cinnamate is the chemical compound which is the ester derived from cinnamic acid and benzyl alcohol.