Eucalyptol is a
monoterpenoid. 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 ...
. 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, XaAE ...
-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, anti ...
.
Eucalyptol forms crystalline
adducts 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 astatine. ...
,
''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 ...
, and
phosphoric acid. 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'' 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,
confectionery
Confectionery is the Art (skill), 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 overlappi ...
,
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. 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
mouthwashes, 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 medications taken individually or in combination as a treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including ...
.
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 t ...
and
insect repellent 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
''Euglossa imperialis'' is a bee species in the family Apidae. It is considered to be one of the most important pollinators to many Neotropical orchid species in mainland tropical America. It is also one of the most common non-parasitic euglos ...
'', 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 of 2.48g/kg (rabbits).
List of plants that contain eucalyptol
* ''
Aframomum corrorima''
* ''
Artemisia tridentata''
* ''
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''. Alternative ...
''
* ''
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 dives''
* ''
Eucalyptus dumosa''
* ''
Eucalyptus globulus''
* ''
Eucalyptus goniocalyx''
* ''
Eucalyptus horistes''
* ''
Eucalyptus kochii''
* ''
Eucalyptus leucoxylon''
* ''
Eucalyptus largiflorens''
* ''
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 ...
''
* ''
Eucalyptus polybractea''
* ''
Eucalyptus radiata''
* ''
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 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''
* ''
Hedychium coronarium'', butterfly lily
* ''
Helichrysum gymnocephalum''
* ''
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 C ...
'', 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 cookin ...
'', bay laurel, (45%)
* ''
Melaleuca alternifolia'', tea tree, (0–15%)
* ''
Salvia lavandulifolia'', Spanish sage (13%)
* ''
Turnera diffusa'', damiana
* ''
Umbellularia californica'', pepperwood (22.0%)
* ''
Zingiber officinale'', ginger
Compendial status
*
British Pharmacopoeia
*
Martindale: The Extra Pharmacopoeia 31
N.B. Listed as "cineole" in some pharmacopoeias.
See also
*
Camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the k ...
*
Citral
*
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, anti ...
*
Lavandula
*
Menthol
Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, clear or white crystalline substance, which is solid at room temperature ...
*
Mouthwash
References
Further reading
*
External links
*
*
*
{{Transient receptor potential channel modulators
Cooling flavors
Monoterpenes
Ethers