Eucalyptol

Eucalyptol
IUPAC name 1,3,3-trimethyl- 2-oxabicyclo[2,2,2]octane
Other names 1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane 1,8-Cineole 1,8-Epoxy-p-menthane
Identifiers
CAS number	470-82-6 Y
PubChem	2758
ChemSpider	2656 Y
UNII	RV6J6604TK Y
DrugBank	DB03852
KEGG	D04115 Y
ChEMBL	CHEMBL485259 Y
Jmol-3D images	Image 1
SMILES O2C1(CCC(CC1)C2(C)C)C
InChI InChI=1S/C10H18O/c1-9(2)8-4-6-10(3,11-9)7-5-8/h8H,4-7H2,1-3H3 Y Key: WEEGYLXZBRQIMU-UHFFFAOYSA-N Y InChI=1/C10H18O/c1-9(2)8-4-6-10(3,11-9)7-5-8/h8H,4-7H2,1-3H3 Key: WEEGYLXZBRQIMU-UHFFFAOYAY
Properties
Molecular formula	C10H18O
Molar mass	154.249 g/mol
Exact mass	154.1357652 u
Density	0.9225 g/cm3
Melting point	1.5 °C (274.6 K)
Boiling point	176–177 °C (449–450 K)
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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.^[1] 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,^[1] hence the common name of the compound. It is also found in camphor laurel, bay leaves, tea tree, mugwort, sweet basil, wormwood, rosemary, 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 oils (volatile oils), eucalyptol is toxic if ingested at higher than normal doses.^[2]

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 °C and the flash point is 49 °C. Eucalyptol forms crystalline adducts with halogen acids, o-cresol, resorcinol, and phosphoric acid. Formation of these adducts are useful for purification.

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.^[3] 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

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.^[4][5] Eucalyptol is an effective treatment for nonpurulent rhinosinusitis.^[6] 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.^[7] It kills leukaemia cells in vitro.^[8]

Insecticide and repellent

Eucalyptol is used as an insecticide and insect repellent.^[9][10]

Conversely, eucalyptol is one of many compounds that is attractive to males of various species of orchid bees, who apparently gather the chemical to synthesize pheromones; it is commonly used as bait to attract and collect these bees for study.^[11]

List of plants that contain the chemical

• Cinnamomum camphora, Camphor laurel (50%)^[12]
• Eucalyptus cneorifolia^{[citation needed]}
• Eucalyptus dives,^{[citation needed]}
• Eucalyptus dumosa^{[citation needed]}
• Eucalyptus globulus^[13]
• Eucalyptus goniocalyx^{[citation needed]}
• Eucalyptus horistes^{[citation needed]}
• Eucalyptus kochii^{[citation needed]}
• Eucalyptus leucoxylon^{[citation needed]}
• Eucalyptus oleosa^{[citation needed]}
• Eucalyptus polybractea^{[citation needed]}
• Eucalyptus radiata^{[citation needed]}
• Eucalyptus staigeriana^[14]
• Eucalyptus sideroxylon^{[citation needed]}
• Eucalyptus smithii^{[citation needed]}
• Eucalyptus tereticornis^{[citation needed]}
• Eucalyptus viridis^{[citation needed]}
• Kaempferia galanga, Galangal, (5.7%)^[15]
• Laurus nobilis, Bay Laurel, (45%)^{[citation needed]}
• Melaleuca alternifolia, Tea-tree, (0–15%)^{[citation needed]}

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 LD₅₀ is 2480 mg/kg (rat). It is classified as a reproductive toxin for males and females.^[2]

Compendial status

• British Pharmacopoeia ^[16]
• Martindale: The Extra Pharmacopoeia 31 ^[17]

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

See also

• Camphor
• Citral
• Eucalyptus oil
• Lavender
• Menthol
• Mouthwash
• Vaporizer^{[disambiguation needed ]}

Notes and references

1. ^ ^{a b} Boland, Brophy & House 1991, p. 6
2. ^ ^{a b} Material Safety Data Sheet - Cineole MSDS, Bio Org
3. ^ Harborne, J.B., Baxter, H.. Chemical Dictionary of Economic Plants. ISBN 0-471-49226-4. 
4. ^ Juergens UR, Dethlefsen U, Steinkamp G, Gillissen A, Repges R, Vetter H (March 2003). "Anti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial". Respir Med 97 (3): 250–6. doi:10.1053/rmed.2003.1432. PMID 12645832. 
5. ^ Juergens, U., Engelen, T., Racké, K., Stöber, M., Gillissen, A., Vetter, H. (2004). "Inhibitory activity of 1,8-cineol (eucalyptol) on cytokine production in cultured human lymphocytes and monocytes". Pulmonary Pharmacology & Therapeutics 17 (5): 281–7. doi:10.1016/j.pupt.2004.06.002. PMID 15477123. http://linkinghub.elsevier.com/retrieve/pii/S1094553904000562. 
6. ^ Kehrl W, Sonnemann U, Dethlefsen U (2004). "Therapy for acute nonpurulent rhinosinusitis with cineole: results of a double-blind, randomized, placebo-controlled trial". Laryngoscope 114 (4): 738–42. doi:10.1097/00005537-200404000-00027. PMID 15064633. 
7. ^ Santos FA, Rao VSN (2000). "Antiinflammatory and antinociceptive effects of 1,8-cineole a terpenoid oxide present in many plant essential oils". Phytotherapy research 14 (4): 240–4. doi:10.1002/1099-1573(200006)14:4<240::AID-PTR573>3.0.CO;2-X. 
8. ^ Moteki H, Hibasami H, Yamada Y, Katsuzaki H, Imai K, Komiya T (2002). "Specific induction of apoptosis by 1,8-cineole in two human leukemia cell lines, but not a in human stomach cancer cell line". Oncol. Rep. 9 (4): 757–60. PMID 12066204. 
9. ^ Klocke, J.A., Darlington, M.V., Balandrin11, M.F. (December 1987). "8-Cineole (Eucalyptol), a mosquito feeding and ovipositional repellent from volatile oil of Hemizonia fitchii (Asteraceae)". Journal of Chemical Ecology 13 (12). http://www.springerlink.com/content/k702041145w0373j/. 
10. ^ Sfara V, Zerba EN, Alzogaray RA (May 2009). "Fumigant Insecticidal Activity and Repellent Effect of Five Essential Oils and Seven Monoterpenes on First-Instar Nymphs of Rhodnius prolixus". Journal of Medical Entomology 46 (3): 511–5. doi:10.1603/033.046.0315. 
11. ^ Schiestl FP, Roubik DW (2004). "Odor Compound Detection in Male Euglossine Bees". Journal of Chemical Ecology 29 (1): 253–7. doi:10.1023/A:1021932131526. PMID 12647866. http://www.springerlink.com/content/kv52574k74438848/. 
12. ^ Stubbs, B.J., Brushett, D. (2001). "Leaf oil of Cinnamomum camphora (L.) Nees and Eberm. From Eastern Australia". Journal of Essential Oil Research 13: 51–4. 
13. ^ Maciel M.V. et al (2010). "Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis". Veterinary Parasitology 167 (1): 1–7. doi:10.1016/j.vetpar.2009.09.053. PMID 19896276. 
14. ^ Gilles, M.; Zhao, J.; An, Min; Agboola, Samson (2010). "Chemical composition and antimicrobial properties of essential oils of three Australian Eucalyptus species". Food Chemistry 119 (2): 731–737. doi:10.1016/j.foodchem.2009.07.021. 
15. ^ {{cite journal
    • Zingiber officinale^{[citation needed]}
    | 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.}}
16. ^ The British Pharmacopoeia Secretariat (2009). "Index, BP 2009". http://www.pharmacopoeia.co.uk/pdf/2009_index.pdf. Retrieved 5 July 2009. 
17. ^ Therapeutic Goods Administration. "Chemical Substances". http://www.tga.gov.au/docs/pdf/aan/aanchem.pdf. Retrieved 5 July 2009. 

Further reading

• Boland, D.J.; Brophy, J.J.; House, A.P.N. (1991). Eucalyptus Leaf Oils. ISBN 0-909605-69-6. 

External links

• Eucalyptus at Botanical.com
• Oleum Eucalypti, B.P. Oil of Eucalyptus at Henriette's Herbal
• Safety data for eucalyptol from Oxford University Chemistry Department