View source for Eucalyptol

{{chembox
| Watchedfields = changed
| verifiedrevid = 302586552
|   Name = Eucalyptol
|   ImageFile1 = Eucalyptol.png
<!-- | ImageSize = 200px -->
|   ImageName = Eucalyptol
|   ImageFileL1 = Eucalyptol3D-3.png
|   ImageSizeL1 = 100px
|   ImageFileR1 = Eucalyptol3D-4.png
|   ImageSizeR1 = 100px
|   IUPACName = 1,3,3-trimethyl- 2-oxabicyclo[2,2,2]octane
| OtherNames = 1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane<br> 1,8-Cineole<br> 1,8-Epoxy-p-menthane
| Section1 = {{Chembox Identifiers
|   CASNo_Ref = {{cascite}}
| CASNo = 470-82-6
| ChemSpiderID  = 2656
|   SMILES = CC1(C2CCC(O1)(CC2)C)C
  }}
| Section2 = {{Chembox Properties
|   Formula = C<sub>10</sub>H<sub>18</sub>O
|   MolarMass = 154.249 g/mol
|   Density = 0.9225 g/cm<sup>3</sup>
|   MeltingPt = 1.5 °C (274.6 K)
|   BoilingPt = 176–177 °C (449–450 K)
  }}
}}

'''Eucalyptol''' is a natural [[organic compound]] which is a colorless [[liquid]].  It is a cyclic [[ether]] and a [[monoterpenoid]].

Eucalyptol is also known by a variety of synonyms: 1,8-cineol, 1,8-cineole, [[limonene]] oxide, cajeputol, 1,8-epoxy-p-menthane, 1,8-oxido-p-menthane, eucalyptol, eucalyptole, 1,3,3-trimethyl-2-oxabicyclo[2,2,2]octane, cineol, cineole.

In 1870, [[F.S. Cloez]] identified and ascribed the name ''eucalyptol'' to the dominant portion of ''[[Eucalyptus globulus]]'' oil.<ref name=Boland>{{harvnb|Boland|Brophy|House|1991|p=6}}</ref> ''[[Eucalyptus oil]]'', the generic collective name for oils from the [[Eucalyptus]] genus, should not be confused with the [[chemical compound]] eucalyptol.

==Composition==
Eucalyptol comprises up to 90 percent of the [[essential oil]] of some species of the generic product [[Eucalyptus oil]],<ref name=Boland/> hence the common name of the compound. It is also found in [[camphor laurel]], [[bay leaf|bay leaves]], [[tea tree oil|tea tree]], [[mugwort]], sweet [[basil]], [[Artemisia (genus)|wormwood]], [[rosemary]], [[Common sage|sage]] and other aromatic plant foliage.  Eucalyptol with a purity from 99.6 to 99.8 percent can be obtained in large quantities by fractional distillation of eucalyptus oil.

Although it can be used internally as a [[flavoring]] and [[medicine]] ingredient at very low doses, typical of many [[essential oil]]s (volatile oils), eucalyptol is toxic if ingested at higher than normal doses.<ref name=MSDS/>
==Properties==
Eucalyptol has a fresh [[camphor]]-like smell and a spicy, cooling taste.  It is insoluble in water, but [[miscible]] with ether, ethanol and chloroform. The boiling point is 176&nbsp;°C and the [[flash point]] is 49&nbsp;°C.

==Uses==
===Flavoring and fragrance===
Because of its pleasant spicy aroma and taste, eucalyptol is used in flavorings, fragrances, and cosmetics. Cineole based eucalyptus oil is used as a flavouring at low levels (0.002%) in various products, including [[baked goods]], [[confectionery]], [[meat]] products and [[beverages]].<ref>{{cite book |author=Harborne, J.B., Baxter, H. |title=Chemical Dictionary of Economic Plants |isbn=0-471-49226-4 }}</ref> In a 1994 report released by five top cigarette companies, eucalyptol was listed as one of the 599 additives to cigarettes. It is claimed that it is added to improve the flavor.

===Medicinal===
[[Image:Eucalyptol suppository.jpg|thumb|left|Eucalyptol [[suppository]], for the treatment of some respiratory ailments]]
Eucalyptol is an ingredient in many brands of mouthwash and cough suppressant. It controls airway [[mucus]] hypersecretion and [[asthma]] via [[anti-inflammatory]] [[cytokine]] inhibition.<ref>{{cite journal |doi=10.1053/rmed.2003.1432 |author=Juergens UR, Dethlefsen U, Steinkamp G, Gillissen A, Repges R, Vetter H |title=Anti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial |journal=Respir Med |volume=97 |issue=3 |pages=250–6 |year=2003 |month=March |pmid=12645832 }}</ref><ref>{{cite journal |doi=10.1016/j.pupt.2004.06.002 |author=Juergens, U., Engelen, T., Racké, K., Stöber, M.,  Gillissen, A., Vetter, H. |title=Inhibitory activity of 1,8-cineol (eucalyptol) on cytokine production in cultured human lymphocytes and monocytes |journal=[[Pulmonary Pharmacology & Therapeutics]] |volume=17 |issue=5 |pages=281–7 |year=2004 |url=http://linkinghub.elsevier.com/retrieve/pii/S1094553904000562}}</ref>
Eucalyptol is an effective treatment for nonpurulent [[rhinosinusitis]].<ref>{{cite journal |author=Kehrl W, Sonnemann U, Dethlefsen U |title=Therapy for acute nonpurulent rhinosinusitis with cineole: results of a double-blind, randomized, placebo-controlled trial |journal=Laryngoscope |volume=114 |issue=4 |pages=738–42 |year=2004 |pmid=15064633 |doi =10.1097/00005537-200404000-00027 }}</ref> Research showed that treated subjects experienced less headache on bending, frontal headache, sensitivity of pressure points of trigeminal nerve, impairment of general condition, nasal obstruction, and rhinological secretion. Side effects from treatment were minimal.

Eucalyptol reduces inflammation and pain when applied topically.<ref>{{cite journal |doi=10.1002/1099-1573(200006)14:4<240::AID-PTR573>3.0.CO;2-X |author=Santos FA, Rao VSN |title=Antiinflammatory and antinociceptive effects of 1,8-cineole a terpenoid oxide present in many plant essential oils |journal=[[Phytotherapy research]] |volume=14 |issue=4 |pages=240–4 |year=2000 }}</ref> It kills [[leukaemia]] cells ''[[in vitro]]''.<ref>{{cite journal |author=Moteki H, Hibasami H, Yamada Y, Katsuzaki H, Imai K, Komiya T |title=Specific induction of apoptosis by 1,8-cineole in two human leukemia cell lines, but not a in human stomach cancer cell line |journal=Oncol. Rep. |volume=9 |issue=4 |pages=757–60 |year=2002 |pmid=12066204 }}</ref>


===Insecticide and repellent===
Eucalyptol is used as an [[insecticide]] and [[insect repellent]].<ref>{{cite journal |author=Klocke, J.A., Darlington, M.V., Balandrin11, M.F. |title=8-Cineole (Eucalyptol), a mosquito feeding and ovipositional repellent from volatile oil of ''Hemizonia fitchii (Asteraceae)'' |journal=[[Journal of Chemical Ecology]] |volume=13 |issue=12 |month=December |year=1987 |url=http://www.springerlink.com/content/k702041145w0373j/}}</ref><ref>{{cite journal |doi=10.1603/033.046.0315 |author=Sfara V, Zerba EN, Alzogaray RA |title=Fumigant Insecticidal Activity and Repellent Effect of Five Essential Oils and Seven Monoterpenes on First-Instar Nymphs of ''[[Rhodnius prolixus]]'' |journal=[[Journal of Medical Entomology]] |volume=46 |issue=3 |pages=511–5 |month=May |year=2009 }}</ref>

Conversely, eucalyptol is one of many compounds that is attractive to males of various species of [[orchid bee]]s, who apparently gather the chemical to synthesize pheromones; it is commonly used as bait to attract and collect these bees for study.<ref>{{cite journal |doi=10.1023/A:1021932131526 |author=Schiestl FP, Roubik DW |title=Odor Compound Detection in Male Euglossine Bees |journal=Journal of Chemical Ecology |volume=29 |issue=1 |pages=253–7 |year=2004 |url=http://www.springerlink.com/content/kv52574k74438848/ |pmid=12647866}}</ref>

==List of plants that contain the chemical==
* ''[[Cinnamomum camphora]]'', Camphor laurel (50%)<ref>{{cite journal |author=Stubbs, B.J., Brushett, D. |title=Leaf oil of ''Cinnamomum camphora (L.)'' Nees and Eberm. From Eastern Australia |journal=Journal of Essential Oil Research |volume=13 |pages=51–4 |year=2001 }}</ref>
* ''[[Eucalyptus cneorifolia]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus dives]]'', {{Citation needed|date=January 2010}}
* ''[[Eucalyptus dumosa]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus globulus]]''<ref>{{cite journal |author = Maciel M.V. ''et al'' |year=2010 |title=Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis |journal=Veterinary Parasitology |volume=167 |issue=1 |pages=1–7 |doi=10.1016/j.vetpar.2009.09.053 |pmid = 19896276 }}</ref>
* ''[[Eucalyptus goniocalyx]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus horistes]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus kochii]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus leucoxylon]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus oleosa]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus polybractea]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus radiata]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus staigeriana]]''<ref>{{cite journal |last1=Gilles |first1=M. |last2=Zhao |first2=J. |last3=An |first3=Min |last4=Agboola |first4=Samson |year=2010 |title=Chemical composition and antimicrobial properties of essential oils of three Australian Eucalyptus species |journal=Food Chemistry |volume=119 |issue=2 |pages=731–737 |doi=10.1016/j.foodchem.2009.07.021 }}</ref>
* ''[[Eucalyptus sideroxylon]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus smithii]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus tereticornis]]'' {{Citation needed|date=January 2010}}
* ''[[Eucalyptus viridis]]'' {{Citation needed|date=January 2010}}
* ''[[Kaempferia galanga]]'', Galangal, (5.7%)<ref name=ceor>{{cite journal
  | last = Wong
  | first = K. C.
  | title = Compositon of the essential oil of rhizomes of ''Kaempferia Galanga L.''
  | journal = Flavour and Fragrance Journal
  | volume = 7
  | issue = 5
  | pages = 263–6
  | date = 2006
  | doi = 10.1002/ffj.2730070506
  | last2 = Ong
  | first2 = K. S.
  | last3 = Lim
  | first3 = C. L.}}</ref>
* ''[[Laurus nobilis]]'', Bay Laurel, (45%) {{Citation needed|date=January 2010}}
* ''[[Melaleuca alternifolia]]'', Tea-tree, (0–15%) {{Citation needed|date=January 2010}}

==Toxicology==
In higher than normal doses eucalyptol is hazardous via [[ingestion]], [[skin]] contact or [[inhalation]]. It can have acute health effects on [[behaviour]], [[respiratory tract]] and [[nervous system]]. The [[acute]] [[oral]] [[toxicity]] ([[LD50]]) is 2480&nbsp;mg/kg (rat). It is classified as a [[reproductive]] [[toxin]] for males and females.<ref name=MSDS>[http://www.bioorg.com/New%20Docs%204-11/BioScent/BioScent%20Eucalyptol/BioScent%20Eucalyptol%20FCC%20MSDS.doc''Material Safety Data Sheet - Cineole MSDS'', Bio Org]</ref>

==Compendial status==
* [[British Pharmacopoeia]] <ref name=ib29>{{cite web
  | last = The British Pharmacopoeia Secretariat
  | first =
  | authorlink =
  | coauthors =
  | title = Index, BP 2009
  | work =
  | publisher =
  | date = 2009
  | url = http://www.pharmacopoeia.co.uk/pdf/2009_index.pdf
  | format =
  | doi =
  | accessdate = 5 July 2009
  }}</ref>
* [[Martindale: The Extra Pharmacopoeia]] 31 <ref name=cs>{{cite web
  | last = [[Therapeutic Goods Administration]]
  | first =
  | authorlink =
  | coauthors =
  | title = Chemical Substances
  | work =
  | publisher =
  | date =
  | url = http://www.tga.gov.au/docs/pdf/aan/aanchem.pdf
  | format =
  | doi =
  | accessdate = 5 July 2009
  }}</ref>

N.B. Listed as "cineole" in some pharmacopoeia.

==Notes and references==
{{Reflist}}

==Further reading==
*{{cite book |last1=Boland |first1=D.J. |last2=Brophy |first2=J.J. |first3=A.P.N. |last3=House |title=Eucalyptus Leaf Oils |year=1991 |isbn=0-909605-69-6 |ref=harv }}

==See also==
* [[Camphor]]
* [[Citral]]
* [[Eucalyptus oil]]
* [[Lavender]]
* [[Menthol]]
* [[Mouthwash]]
* [[Vaporizer]]

==External links==
* [http://www.botanical.com/botanical/mgmh/e/eucaly14.html Eucalyptus] at Botanical.com
* [http://www.henriettesherbal.com/eclectic/bpc1911/eucalyptus_oleu.html Oleum Eucalypti, B.P. Oil of Eucalyptus] at Henriette's Herbal
* [http://ptcl.chem.ox.ac.uk/MSDS/CI/1,8-cineole.html Safety data for eucalyptol] from Oxford University Chemistry Department

[[Category:Cigarette additives]]
[[Category:Ethers]]
[[Category:Cooling flavors]]
[[Category:Epoxides]]
[[Category:Monoterpenes]]

[[de:1,8-Cineol]]
[[es:Aceite de eucalipto]]
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[[it:Eucaliptolo]]
[[hu:Cineol]]
[[ja:シネオール]]
[[pl:Eukaliptol]]
[[ru:Цинеол]]
[[Category:2Fix]]