1,8-cineole  (Eucalyptol) is a natural component, terpenoid oxide or monoterpene  that is mainly obtained from the plant Eucalyptus (Eucalyptus globulus) belonging to the Myrtaceae family.

1,8-Dihydroxy-10-carboxy-p-menthane, 2-hydroxy-cineole and 3-hydroxy-cineole are the main metabolites of eucalyptol.

It is also found in all mint species and in spices such as Aframomum melegueta and Aframomum danielli.

Industrially it appears as a colourless to yellowish liquid. Stable. Inflammable. Incompatible with acids, bases and strong oxidising agents.

What it is used for and where

Medical

Included in cough mouthwashes, it controls hypersecretion in the airways and asthma through the inhibition of anti-inflammatory cytokines. 

The most interesting ingredients, from a health point of view, of Eucalyptus are mainly alkaloids, flavonoids, pigments, phenolics, terpenes, amides, steroids and essential oils. Recent studies have shown its antimicrobial effects against bacterial, fungal, parasitic and viral agents (1).

Methanol extract (8:2) has shown significant anti-inflammatory activity through membrane stabilisation and other processes involving protein denaturation (2).

Another interesting application of eucalyptus essential oil is its larvicidal and insecticidal potential and can therefore be used in the community in artificial water bodies as an eco-friendly vector control measure in the era of increasing resistance to chemical insecticides (3).

The data emerging from this study clarify other health-oriented characteristics of the use of the aqueous leaf extract of Eucalyptus globulus that may play an important role as an antihypertensive agent to reduce the burden of cardiovascular complications (4).

Cosmetics

Antiseptic and healing agent.

Food

Flavouring at low levels (0.002%) in meat products, bakery products, confectionery.

The most relevant studies on this ingredient have been selected with a summary of their contents:

Eucalyptol studies

Appearance	Yellowish liquid
Boiling Point	174.0±8.0°C at 760 mmHg
Melting Point	1.5ºC
Flash Point	50.9±15.3°C
Density	0.9±0.1 g/cm3
Vapor Pressure	1.6±0.3 mmHg at 25°C
Refraction Index	1.461
PSA	9.23000
LogP	2.82
Specific gravity	0.920－0.925（20℃）
Refractive index	1.4550－1.4600（20℃）
Optical rotation	-0.5°—﹢0.5°（20℃）
Solubility	1:5 / 60% alcohol solution
Chemical Safety

• Molecular Formula   C₁₀H₁₈O
• Molecular Weight  154.25
• Exact Mass    154.135757
• CAS   470-82-6
•  UNII    RV6J6604TK
• EC Number   207-431-5
• DSSTox Substance ID  DTXSID4020616
• IUPAC  1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane
• InChl=1S/C10H18O/c1-9(2)8-4-6-10(3,11-9)7-5-8/h8H,4-7H2,1-3H3
• InChl Key      WEEGYLXZBRQIMU-UHFFFAOYSA-N
• SMILES  CC1(C2CCC(O1)(CC2)C)C
• MDL number  MFCD00167977
• PubChem Substance ID    24893017
• ChEBI  27961
• RTECS  OS9275000
• FEMA    2465
• JECFA    1234
• Beilstein     105109
• NCI    C107375    C65603    C76772
• RXCUI    21116    
• NSC      760388     6171
• UN    1993

Synonyms:

• Cineole
• Eucalyptol
• 1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane
• 1,8-Epoxy-p-menthane

References____________________________________________________________________

(1) Ghasemian A, Eslami M, Hasanvand F, Bozorgi H, Al-Abodi HR.  Eucalyptus camaldulensis properties for use in the eradication of infections.  Comp Immunol Microbiol Infect Dis. 2019 Aug;65:234-237. doi: 10.1016/j.cimid.2019.04.007.

(2) Ashour RMS, Okba MM, Menze ET, El Gedaily RA.  J  Eucalyptus Sideroxylon Bark Anti-inflammatory Potential, Its UPLC-PDA-ESI-qTOF-MS Profiling, and Isolation of a New Phloroglucinol.  Chromatogr Sci. 2019 Jul 1;57(6):565-574. doi: 10.1093/chromsci/bmz029.

(3) Kaura T, Mewara A, Zaman K, Sharma A, Agrawal SK, Thakur V, Garg A, Sehgal R. Utilizing larvicidal and pupicidal efficacy of Eucalyptus and neem oil against Aedes mosquito: An approach for mosquito control.    Trop Parasitol. 2019 Jan-Jun;9(1):12-17. doi: 10.4103/tp.TP_35_18. Epub 2019 May 22.

(4)  Ajebli M, Eddouks M.  Eucalyptus globulus possesses antihypertensive activity in L-NAME-induced hypertensive rats and relaxes isolated rat thoracic aorta through nitric oxide pathway.   Nat Prod Res. 2019 Apr 10:1-3. doi: 10.1080/14786419.2019.1598992