Farnesene
From Wikipedia, the free encyclopedia
| (E,E)-α-Farnesene | |
|---|---|
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| IUPAC name | α: 3,7,11-trimethyl-1,3,6,10-dodecatetraene |
| Identifiers | |
| CAS number | |
| SMILES | α: CC(C)=CCCC(C)=CCC=C(C)C=C β: CC(C)=CCCC(C)=CCCC(C=C)=C |
| Properties | |
| Molecular formula | C15H24 |
| Molar mass | 204.36 g/mol |
| Boiling point |
α-(Z): 125 at 12 mmHg |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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The term farnesene refers to a set of six closely related chemical compounds which all are sesquiterpenes. α-Farnesene and β-farnesene are isomers, differing by the location of one double bond. α-Farnesene is 3,7,11-trimethyl-1,3,6,10-dodecatetraene and β-farnesene is 7,11-dimethyl-3-methylene-1,6,10-dodecatriene. The alpha form can exist as four stereoisomers that differ about the geometry of two of its three internal double bonds (the stereoisomers of the third internal double bond are identical). The beta isomer exists as two stereoisomers about the geometry of its central double bond.
Two of the α-farnesene stereoisomers are reported to occur in Nature. (E,E)-α-Farnesene is the most common isomer. It is found in the coating of apples, and other fruits, and it is responsible for the characteristic green apple odour. Its oxidation by air gives compounds that are damaging to the fruit. The oxidation products injure cell membranes which eventually causes cell death in the outermost cell layers of the fruit, resulting in a storage disorder known as scald. (Z,E)-α-Farnesene has been isolated from the oil of perilla. Both isomers are also insect semiochemicals; they act as alarm pheremones in termites or food attractants for the apple tree pest, the codling moth. α-Farnesene is also the chief compound contributing to the scent of gardenia, making up ~65% of the headspace constituents[1].
β-Farnesene has one naturally occurring isomer. The E isomer is a constituent of various essential oils. It is also released by aphids as an alarm pheremone upon death to warn away other aphids. Several plants, including potato species, have been shown to synthesize this pheromone as a natural insect repellent.
[edit] See also
[edit] References
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The references in this article would be clearer with a different or consistent style of citation, footnoting, or external linking. |
- ^ Wang, Shau-Chun; Tseng, Ting-Yu; Huanga, Chih-Min & Tsaic, Tung-Hu (5 December 2004), “Gardenia herbal active constituents: applicable separation procedures”, Journal of Chromatography B 812 (1-2)
- Avé, D. A., Gregory, P., Tingey, W. M., "Aphid repellent sesquiterpenes in glandular trichomes of Solanum berthaultii and S. tuberosum", Entomologia Experimentalis et Applicata 44, 131 - 138 (July 1987)
- Gibson, R. W. & Pickett, J. A., "Wild potato repels aphids by release of aphid alarm pheromone", Nature 302, 608 - 609 (14 April 1983)
- Hern, A. & Dorn, S., "Sexual dimorphism in the olfactory orientation of adult Cydia pomonella in response to alpha-farnesene", Entomologia Experimentalis et Applicata 92, 63 - 72 (July 1999)
- Šobotník, J., Hanus, R., Kalinová, B., Piskorski, R., Cvačka, J., Bourguignon, T., Roisin, Y., "(E,E)-α-Farnesene, an Alarm Pheromone of the Termite Prorhinotermes canalifrons", Journal of Chemical Ecology 34, 478 - 486 (April 2008)
