Eucalyptol is a

monoterpenoid Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen funct ...

. A colorless liquid, it is a bicyclic

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be c ...

. Eucalyptol has a fresh

mint MiNT is Now TOS (MiNT) is a free software alternative operating system kernel for the Atari ST system and its successors. It is a multi-tasking alternative to TOS and MagiC. Together with the free system components fVDI device drivers, XaA ...

-like smell and a spicy, cooling taste. It is insoluble in water, but

miscible Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies ...

with organic solvents. Eucalyptol makes up ~70% - 90% of

eucalyptus oil Eucalyptus oil is the generic name for distilled oil from the leaf of ''Eucalyptus'', a genus of the plant family Myrtaceae native to Australia and cultivated worldwide. Eucalyptus oil has a history of wide application, as a pharmaceutical, ant ...

. Eucalyptol forms crystalline

adduct An adduct (from the Latin ''adductus'', "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all co ...

s with

hydrohalic acids In chemistry, hydrogen halides (hydrohalic acids when in the aqueous phase) are diatomic, inorganic compounds that function as Arrhenius acids. The formula is HX where X is one of the halogens: fluorine, chlorine, bromine, iodine, or astat ...

, ''o''-cresol,

resorcinol Resorcinol (or resorcin) is an organic compound with the formula C6H4(OH)2. It is one of three isomeric benzenediols, the 1,3-isomer (or '' meta''-isomer). Resorcinol crystallizes from benzene as colorless needles that are readily soluble in w ...

, and

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...

. Formation of these adducts is useful for purification. In 1870, F. S. Cloez identified and ascribed the name "eucalyptol" to the dominant portion of ''

Eucalyptus globulus ''Eucalyptus globulus'', commonly known as southern blue gum or blue gum, is a species of tall, evergreen tree endemic to southeastern Australia. This ''Eucalyptus'' species has mostly smooth bark, juvenile leaves that are whitish and waxy on ...

'' oil.

Uses

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 Baking is a method of preparing food that uses dry heat, typically in an oven, but can also be done in hot ashes, or on hot stones. The most common baked item is bread but many other types of foods can be baked. Heat is gradually transferred " ...

confectionery Confectionery is the art of making confections, which are food items that are rich in sugar and carbohydrates. Exact definitions are difficult. In general, however, confectionery is divided into two broad and somewhat overlapping categories ...

meat Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...

products, and

beverages A drink or beverage is a liquid intended for human consumption. In addition to their basic function of satisfying thirst, drinks play important roles in human culture. Common types of drinks include plain drinking water, milk, juice, smoothies a ...

. In a 1994 report released by five top cigarette companies, eucalyptol was listed as one of the 599 additives to cigarettes. It is claimed to be added to improve the flavor. Eucalyptol is an ingredient in commercial

mouthwash Mouthwash, mouth rinse, oral rinse, or mouth bath is a liquid which is held in the mouth passively or swilled around the mouth by contraction of the perioral muscles and/or movement of the head, and may be gargling, gargled, where the head is ti ...

es, and has been used in

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

as a

cough suppressant Cold medicines are a group of medicinal, medications taken individually or in Combination drug, combination as a Symptomatic treatment, treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The t ...

Other

Eucalyptol exhibits

insecticidal Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

and

insect repellent An insect repellent (also commonly called "bug spray") is a substance applied to skin, clothing, or other surfaces to discourage insects (and arthropods in general) from landing or climbing on that surface. Insect repellents help prevent and cont ...

properties. In contrast, eucalyptol is one of many compounds that are attractive to males of various species of

orchid bee The tribe Euglossini, in the subfamily Apinae, commonly known as orchid bees or euglossine bees, are the only group of corbiculate bees whose non-parasitic members do not all possess eusocial behavior. Description Most of the tribe's species ...

s, which gather the chemical to synthesize pheromones; it is commonly used as bait to attract and collect these bees for study. One such study with '' Euglossa imperialis'', a nonsocial orchid bee species, has shown that the presence of cineole (also eucalyptol) elevates territorial behavior and specifically attracts the male bees. It was even observed that these males would periodically leave their territories to forage for chemicals such as cineole, thought to be important for attracting and mating with females, to synthesize pheromones.

Toxicology

It has low toxicity (hence its use in foods), with an

LD50 In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the ...

of 2.48g/kg (rabbits).

List of plants that contain eucalyptol

* ''

Aframomum corrorima ''Aframomum corrorima'' is a species of flowering plant in the ginger family, Zingiberaceae. It's a herbaceous perennial that produces leafy stems 1–2 meters tall from rhizomatous roots. The alternately-arranged leaves are dark green, 10–30&n ...

'' * ''

Artemisia tridentata ''Artemisia tridentata'', commonly called big sagebrush,MacKay, Pam (2013), ''Mojave Desert Wildflowers'', 2nd ed., , p. 264. Great Basin sagebrush or (locally) simply sagebrush, is an aromatic shrub from the family Asteraceae, which grows in ari ...

'' * ''

Cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: ''Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternatively ...

'' * ''

Cinnamomum camphora ''Camphora officinarum'' is a species of evergreen tree that is commonly known under the names camphor tree, camphorwood or camphor laurel. Description ''Camphora officinarum'' is native to China south of the Yangtze River, Taiwan, southern ...

'', camphor laurel (50%) * ''

Eucalyptus cneorifolia ''Eucalyptus cneorifolia'', the Kangaroo Island narrow-leaf mallee, is a native tree of Kangaroo Island, South Australia. Description The mallee tree will grow to in height, it has an upright habit and can have a single or multiple stems with a ...

'' * ''

Eucalyptus dives ''Eucalyptus dives'', commonly known as the broad-leaved peppermint or blue peppermint, is a species of tree that is endemic to south-eastern Australia. It has rough, finely fibrous bark on the trunk and larger branches, smooth bark above, lance- ...

'' * ''

Eucalyptus dumosa ''Eucalyptus dumosa'', commonly known as the white mallee, dumosa mallee, or Congoo mallee, is a species of mallee that is endemic to south eastern Australia. It usually has rough, flaky grey bark on the lower trunk, smooth bark above, lance-shap ...

'' * ''

Eucalyptus goniocalyx ''Eucalyptus goniocalyx'', commonly known as long-leaved box, olive-barked box or bundy, is a species of small to medium-sized tree that is Endemism, endemic to southeastern Australia. It has rough, fibrous or flaky bark, lance-shaped to curved a ...

'' * ''

Eucalyptus horistes ''Eucalyptus horistes'' is a species of Mallee (habit), mallee or small tree that is Endemism, endemic to Western Australia. It has smooth greyish bark, often with rough, firm fibrous bark on the base or all of the trunk, lance-shaped to ellipti ...

'' * ''

Eucalyptus kochii ''Eucalyptus kochii'', commonly known as oil mallee, is a species of mallee, sometimes a tree, and is endemic to Western Australia. It has rough, flaky or fibrous bark on the trunk, smooth grey bark above, linear to narrow lance-shaped adult lea ...

'' * ''

Eucalyptus leucoxylon ''Eucalyptus leucoxylon'', commonly known as yellow gum, blue gum or white ironbark, is a species of small to medium-sized tree that is endemic to south-eastern continental Australia. It has smooth yellowish bark with some rough bark near the bas ...

'' * ''

Eucalyptus largiflorens ''Eucalyptus largiflorens'', or black box or river box, is a tree that is endemic to Australia. It has rough, fibrous or flaky bark, dull greenish-grey, lance-shaped leaves, oval to club-shaped green to yellow flower buds, white flowers and hemi ...

'' * ''

Eucalyptus oleosa ''Eucalyptus oleosa'', commonly known as the red mallee, glossy-leaved red mallee, acorn mallee, oil mallee or giant mallee, is a tree or mallee that is native to Australia. The leaves were once harvested for the production of cineole based e ...

'' * ''

Eucalyptus polybractea ''Eucalyptus polybractea'', commonly known as the blue-leaved mallee or simply blue mallee, is a species of mallee that is endemic to south-eastern Australia. It has rough, fibrous or flaky bark on the lower part of the trunk, smooth greyish o ...

'' * ''

Eucalyptus radiata ''Eucalyptus radiata'', commonly known as the narrow-leaved peppermint or Forth River peppermint, is a species of tree that is endemic to south-eastern Australia. It has rough, fibrous to flaky bark on the trunk and larger branches, smooth grey b ...

'' * ''

Eucalyptus rossii ''Eucalyptus rossii'', commonly known as inland scribbly gum or white gum, is a species of small to medium-sized tree that is endemic to New South Wales and the Australian Capital Territory. It has smooth bark with insect scribbles, lance-shap ...

'' * ''

Eucalyptus sideroxylon ''Eucalyptus sideroxylon'', commonly known as mugga ironbark, or red ironbark is a small to medium-sized tree that is endemic to eastern Australia. It has dark, deeply furrowed ironbark, lance-shaped adult leaves, flower buds in groups of se ...

'' * ''

Eucalyptus smithii ''Eucalyptus smithii'', commonly known as the gully gum, gully peppermint, blackbutt peppermint, or ironbark peppermint, is a species of medium-sized to tall tree, sometimes a mallee, that is endemic to southeastern Australia. It has rough, comp ...

'' * ''

Eucalyptus staigeriana ''Eucalyptus staigeriana'', commonly known as the lemon-scented ironbark, is a species of small ironbark tree that is endemic to the Cape York Peninsula. It has rough ironbark on the trunk and branches, lance-shaped to egg-shaped leaves that sme ...

'' * ''

Eucalyptus tereticornis ''Eucalyptus tereticornis'', commonly known as forest red gum, blue gum or red irongum, is a species of tree that is native to eastern Australia and southern New Guinea. It has smooth bark, lance-shaped to curved adult leaves, flower buds in grou ...

'' * ''

Eucalyptus viridis ''Eucalyptus viridis'', commonly known as the green mallee, is a species of mallee or small tree that is endemic to south-eastern, continental Australia. It has rough fibrous or flaky bark on the lower trunk, smooth bark above, linear to narrow ...

'' * ''

Hedychium coronarium ''Hedychium coronarium'', the white garland-lily or white ginger lily, is a perennial plant, perennial flowering plant in the ginger family Zingiberaceae, native species, native to the forest understorey of Asia. Other common names include butt ...

'', butterfly lily * ''

Helichrysum gymnocephalum ''Helichrysum gymnocephalum'' is a species of flowering plant in the family Asteraceae found in Madagascar. It is used locally for its alleged aphrodisiac, antiseptic, and stimulant properties, and also as a treatment for bronchitis. The essent ...

'' * ''

Kaempferia galanga ''Kaempferia galanga'', commonly known as kencur, aromatic ginger, sand ginger, cutcherry, is a monocotyledonous plant in the ginger family, and one of four plants called galangal. It is found primarily in open areas in Indonesia, southern Ch ...

'', galangal, (5.7%) * ''

Laurus nobilis ''Laurus nobilis'' is an aromatic evergreen tree or large shrub with green, glabrous (smooth) leaves. It is in the flowering plant family Lauraceae. It is native to the Mediterranean region and is used as bay leaf for seasoning in cooking. I ...

'', bay laurel, (45%) * ''

Melaleuca alternifolia ''Melaleuca alternifolia'', commonly known as tea tree, is a species of tree or tall shrub in the myrtle family, Myrtaceae. Endemic to Australia, it occurs in southeast Queensland and the north coast and adjacent ranges of New South Wales wher ...

'', tea tree, (0–15%) * '' Salvia lavandulifolia'', Spanish sage (13%) * ''

Turnera diffusa ''Turnera diffusa'', known as damiana, is a shrub native to southern Texas in the United States, Central America, Mexico, South America, and the Caribbean. It belongs to the family Passifloraceae. Damiana is a relatively small, woody shrub tha ...

'', damiana * ''

Umbellularia californica ''Umbellularia californica'' is a large hardwood tree native to coastal forests and the Sierra foothills of California, and to coastal forests extending into Oregon. It is endemic to the California Floristic Province. It is the sole species in th ...

'', pepperwood (22.0%) * ''

Zingiber officinale Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice and a folk medicine. It is a herbaceous perennial which grows annual pseudostems (false stems made of the rolled bases of l ...

'', ginger

Compendial status

British Pharmacopoeia The ''British Pharmacopoeia'' (''BP'') is the national pharmacopoeia of the United Kingdom. It is an annually published collection of quality standards for medicinal substances in the UK, which is used by individuals and organisations involve ...

* Martindale: The Extra Pharmacopoeia 31 N.B. Listed as "cineole" in some pharmacopoeias.

References

External links

* * * {{Transient receptor potential channel modulators Cooling flavors Monoterpenes Ethers

Uses

Other

Toxicology

List of plants that contain eucalyptol

Compendial status

See also

References

Further reading

External links