Myrcene
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Preferred IUPAC name
7-Methyl-3-methylideneocta-1,6-diene | |
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3D model (
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ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard
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100.004.203 |
KEGG | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C10H16 | |
Molar mass | 136.238 g·mol−1 |
Density | 0.794 g/cm3 |
Melting point | < −10 °C (14 °F; 263 K) |
Boiling point | 166 to 168 °C (331 to 334 °F; 439 to 441 K)[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from Myrcia, from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature.[3]
Production
Myrcene is often produced commercially by the pyrolysis (400 °C) of β-pinene, which is obtained from turpentine.[3] It is rarely obtained directly from plants.[4]
Plants biosynthesize myrcene via geranyl pyrophosphate (GPP), which isomerizes into linalyl pyrophosphate. The release of the pyrophosphate (OPP) and a proton completes the conversion.[5]
Occurrence
It could in principle be extracted from any number of plants, such as
Of the several terpenes extracted from Humulus lupulus (hops), the largest monoterpenes fraction is β-myrcene. One study of the chemical composition of the fragrance of Cannabis sativa found β-myrcene to compose between 29.4% and 65.8% of the steam-distilled essential oil for the set of fiber and drug strains tested.[8] Additionally, myrcene is thought to be the predominant terpene found in modern cannabis cultivars within North America. Interestingly, photo-oxidation of myrcene has been shown to rearrange the molecule into a novel terpene known as "hashishene" which is named for its abundance in hashish.[9]
It is found in the South African Adenandra villosa (50%).[10] & Brazilian Schinus molle (40%)[11] Myrcene is also found in Myrcia cuprea petitgrain (up to 48%),[12] bay leaf, juniper berry, cannabis, and hops.[3][13]
Use in fragrance and flavor industries
Myrcene is an intermediate used in the
Both myrcene and myrcenol undergo
Myrcene also contributes a peppery and balsam aroma in beer.[14][15]
As of October 2018, the U.S. FDA withdrew authorization for the use of myrcene as a synthetic flavoring substance for use in food, without regard to its continuing stance that this substance does not pose a risk to public health under the conditions of its intended use.[16]
Health and safety
In 2015, beta-myrcene was added to California's Prop 65 list of chemicals known to the state of California to cause cancer or reproductive harm.[17]
See also
- Perfume allergy
References
- ^ Merck Index, 11th Edition, 6243
- ^ ISBN 3-527-30673-0.
- ^ PMID 20013989.
- ^ ISBN 3-527-30673-0.
- ISBN 0-471-49641-3.
- PMID 28355238.
- PMID 15453700.
- ^ "Essential oil of Cannabis sativa L. strains". druglibrary.net. Retrieved 2017-06-08.
- ^ "Myrcene Terpene for Extracts, vape and concentrates". ElevationTerpenes. Retrieved 2020-12-03.
- ^ Baser, K. H. C.; Demirci, B.; Ozek, T.; Viljoen, A. M.; Victor, J. E. (2006). "Composition of the essential oils of two Adenandra species from South Africa". Journal of Essential Oil Research.
- S2CID 92548775.
- doi:10.1002/ffj.1242.
- .
- PMID 23627300.
- PMID 23483584.
- ^ 83 FR 50490
- ^ "Proposition 65". oehha.ca.gov. OEHHA - California Office of Environmental Health Hazard Assessment.