Eucalyptol
Encyclopedia
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. Eucalyptus oil
, the generic collective name for oils from the Eucalyptus
genus, should not be confused with the chemical compound
eucalyptol.
of some species of the generic product Eucalyptus oil
, 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 oil
s (volatile oils), eucalyptol is toxic if ingested at higher than normal doses.
-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 adduct
s with halogen acids
, o-cresol
, resorcinol
, and phosphoric acid
. Formation of these adducts are useful for purification.
, meat
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 that it is added to improve the flavor.
Eucalyptol is an ingredient in many brands of mouthwash and cough suppressant. It controls airway mucus
hypersecretion and asthma
via anti-inflammatory
cytokine
inhibition.
Eucalyptol is an effective treatment for nonpurulent rhinosinusitis. 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. It kills leukaemia cells in vitro
.
and insect repellent
.
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.
, skin
contact or inhalation
. It can have acute health effects on behaviour, respiratory tract
and nervous system
. The acute
oral
is 2480 mg/kg (rat). It is classified as a reproductive toxin
for males and females.
N.B. Listed as "cineole" in some pharmacopoeia.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
which is a colorless liquid
Liquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
. It is a cyclic ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
and a monoterpenoid.
Eucalyptol is also known by a variety of synonyms: 1,8-cineol, 1,8-cineole, limonene
Limonene
Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The more common D isomer possesses a strong smell of oranges. It is used in chemical synthesis as a precursor to carvone and as a renewably-based solvent in cleaning products....
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
F.S. Cloez
F.S. Cloez was a French chemist, who also authored as "S. Cloez", and is known for his pioneering role in analytical chemistry during the 19th century....
identified and ascribed the name eucalyptol to the dominant portion of Eucalyptus globulus
Eucalyptus globulus
The Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m tall. The tallest currently known specimen in Tasmania is 90.7 m tall...
oil. Eucalyptus oil
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, antiseptic, repellent, flavouring, fragrance and industrial uses...
, the generic collective name for oils from the Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
genus, should not be confused with the chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
eucalyptol.
Composition
Eucalyptol comprises up to 90 percent of the essential oilEssential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
of some species of the generic product Eucalyptus oil
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, antiseptic, repellent, flavouring, fragrance and industrial uses...
, hence the common name of the compound. It is also found in camphor laurel
Camphor Laurel
Cinnamomum camphora is a large evergreen tree that grows up to 20–30 metres tall. The leaves have a glossy, waxy appearance and smell of camphor when crushed. In spring it produces bright green foliage with masses of small white flowers...
, bay leaves
Bay leaf
Bay leaf refers to the aromatic leaf of the bay laurel . Fresh or dried bay leaves are used in cooking for their distinctive flavor and fragrance. The leaves are often used to flavor soups, stews, braises and pâtés in Mediterranean cuisine...
, tea tree
Tea tree oil
Tea tree oil, or melaleuca oil, is a pale yellow colour to nearly clear essential oil with a fresh camphoraceous odor. It is taken from the leaves of the Melaleuca alternifolia, which is native to the northeast coast of New South Wales, Australia...
, mugwort, sweet basil
Basil
Basil, or Sweet Basil, is a common name for the culinary herb Ocimum basilicum , of the family Lamiaceae , sometimes known as Saint Joseph's Wort in some English-speaking countries....
, wormwood, rosemary
Rosemary
Rosemary, , is a woody, perennial herb with fragrant, evergreen, needle-like leaves and white, pink, purple or blue flowers, native to the Mediterranean region. It is a member of the mint family Lamiaceae, which includes many other herbs, and is one of two species in the genus Rosmarinus...
, sage
Common sage
Salvia officinalis is a small, perennial, evergreen subshrub, with woody stems, grayish leaves, and blue to purplish flowers. It is a member of the family Lamiaceae and is native to the Mediterranean region, though it has naturalized in many places throughout the world...
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
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
ingredient at very low doses, typical of many essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
s (volatile oils), eucalyptol is toxic if ingested at higher than normal doses.
Properties
Eucalyptol has a fresh camphorCamphor
Camphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel , a large evergreen tree found in Asia and also of Dryobalanops aromatica, a giant of the Bornean forests...
-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
Flash point
The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...
is 49 °C. Eucalyptol forms crystalline adduct
Adduct
An adduct is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species...
s with halogen acids
Hydrogen halide
Hydrogen halides are acids resulting from the chemical reaction of hydrogen with one of the halogen elements , which are found in Group 17 of the periodic table. Astatine is not included in the list because it is very rare, unstable and not found as the acid in substantial quantities...
, o-cresol
O-Cresol
ortho-Cresol, also 2-methylphenol, is a phenol, with formula C6H4.It is an isomer of p-cresol, m-cresol and anisole-Chemistry:...
, resorcinol
Resorcinol
Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...
, and phosphoric acid
Phosphoric acid
Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...
. Formation of these adducts are useful for purification.
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, confectioneryConfectionery
Confectionery is the set of food items that are rich in sugar, any one or type of which is called a confection. Modern usage may include substances rich in artificial sweeteners as well...
, meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
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 that it is added to improve the flavor.
Medicinal
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
hypersecretion and asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
via anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
cytokine
Cytokine
Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...
inhibition.
Eucalyptol is an effective treatment for nonpurulent rhinosinusitis. 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. It kills leukaemia cells in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
.
Insecticide and repellent
Eucalyptol is used as an insecticideInsecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
and insect repellent
Insect repellent
An insect repellent is a substance applied to skin, clothing, or other surfaces which discourages insects from landing or climbing on that surface. There are also insect repellent products available based on sound production, particularly ultrasound...
.
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.
List of plants that contain the chemical
- Cinnamomum camphora, Camphor laurel (50%)
- Eucalyptus cneorifoliaEucalyptus cneorifoliaEucalyptus cneorifolia, the Kangaroo Island narrow-leaf mallee, is a native tree of Kangaroo Island, South Australia. It will grow to roughly 5m in height, and produces a small white flower...
- Eucalyptus divesEucalyptus divesEucalyptus dives or broad-leaved peppermint is a small tree native to temperate dry sclerophyll woodlands and forests of south-eastern Australia. The juvenile leaves are ovate and glaucus, and adult leaves are lanceolate to broad-lanceolate. Leaves are aromatic.-Uses:There are two notable...
, - Eucalyptus dumosaEucalyptus dumosaEucalyptus dumosa, White Mallee is a mallee of the relatively dry country of South Australia from the northern Flinders Ranges and Murray Mallee eastwards to central western New South Wales and north western Victoria...
- Eucalyptus globulusEucalyptus globulusThe Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m tall. The tallest currently known specimen in Tasmania is 90.7 m tall...
- Eucalyptus goniocalyxEucalyptus goniocalyxEucalyptus goniocalyx, Long-leaved box is a small to medium-sized tree with rough and persistent bark to the small branches. It is fibrous, greyish, becoming deeply fissured, thick and shaggy in larger trees...
- Eucalyptus horistesEucalyptus horistesEucalyptus horistes is a mallee type Eucalyptus that is native to Western Australia....
- Eucalyptus kochiiEucalyptus kochiiEucalyptus kochii is a native tree of Western Australia.There are two subspecies:* Eucalyptus kochii subsp. kochii* Eucalyptus kochii subsp. plenissimaIt is cultivated in plantations for the production of eucalyptus oil...
- Eucalyptus leucoxylonEucalyptus leucoxylonEucalyptus leucoxylon, commonly known as the Yellow Gum, Blue Gum or White Ironbark, is a small to medium-sized tree with rough bark on the lower 1-2 metres of the trunk, above this, the bark becomes smooth with a white, yellow or bluish-grey surface...
- Eucalyptus oleosaEucalyptus oleosaEucalyptus oleosa, red mallee, is a native tree of Australia. The leaves were once harvested for the production of cineole based eucalyptus oil. These days Eucalyptus cneorifolia is used because of a higher oil content in new growth....
- Eucalyptus polybractea
- Eucalyptus radiataEucalyptus radiataEucalyptus radiata is a medium to tall tree to 30 m high with persistent bark on the trunk and larger branches or persistent to smaller branches. The bark shortly fibrous , grey to grey-brown, shedding in long ribbons...
- Eucalyptus staigerianaEucalyptus staigerianaEucalyptus staigeriana, Lemon Ironbark or Lemon-scented Ironbark, is a small rough barked sclerophyll tree that grows naturally in pure stands on hills in the Palmer River region of Cape York, North Queensland, Australia.-Uses:...
- Eucalyptus sideroxylonEucalyptus sideroxylonEucalyptus sideroxylon, or Mugga, Red Ironbark or Mugga Ironbark, is a small to medium-sized or occasionally tall tree. The bark is persistent on the trunk and large branches, hard and deeply furrowed, dark grey to black, with upper limbs smooth and whitish.Adult leaves are stalked, lanceolate to...
- Eucalyptus smithiiEucalyptus smithiiEucalyptus smithii, or gully gum, is a native tree of northern Victoria and southern New South Wales, Australia. In its natural situation it occurs on the lower slopes, gullies, and swamps - where soils do not dry out....
- Eucalyptus tereticornisEucalyptus tereticornisEucalyptus tereticornis is a species of tree native to eastern Australia.It has a great many common names, of which Forest Red Gum is perhaps the most widely known...
- Eucalyptus viridisEucalyptus viridisEucalyptus viridis is a small native tree of Australia. It naturally occurs in Queensland, New South Wales, Victoria and South Australia....
- Kaempferia galangaKaempferia galangaKaempferia galanga, commonly known as kencur, aromatic ginger, sand ginger, cutcherry or resurrection lily, is a monocotyledonous plant in the ginger family. It is found primarily in open areas in Indonesia, southern China, Taiwan, Cambodia and India, but is also widely cultivated throughout...
, Galangal, (5.7%) - Laurus nobilis, Bay Laurel, (45%)
- Melaleuca alternifoliaMelaleuca alternifoliaMelaleuca alternifolia, commonly known as Narrow-leaved Paperbark, Narrow-leaved Tea-tree, Narrow-leaved Ti-tree, or Snow-in-summer, is a species of tree or tall shrub in the plant genus Melaleuca. Native to Australia, it occurs on the north coast and adjacent ranges of New South Wales...
, Tea-tree, (0–15%)
Toxicology
In higher than normal doses eucalyptol is hazardous via ingestionIngestion
Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in the substance through the mouth into the gastrointestinal tract, such as through eating or drinking...
, skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
contact or inhalation
Inhalation
Inhalation is the movement of air from the external environment, through the air ways, and into the alveoli....
. It can have acute health effects on behaviour, respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
and nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
. The acute
Acute toxicity
Acute toxicity describes the adverse effects of a substance that result either from a single exposure or from multiple exposures in a short space of time...
oral
Oral administration
Oral administration is a route of administration where a substance is taken through the mouth.-Terminology:Per os is an adverbial phrase meaning literally from Latin "by mouth" or "by way of the mouth." The expression is used in medicine to describe a treatment that is taken orally. The...
is 2480 mg/kg (rat). It is classified as a reproductive toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
for males and females.
Compendial status
- British PharmacopoeiaBritish PharmacopoeiaThe British Pharmacopoeia is an annual published collection of quality standards for UK medicinal substances. It is used by individuals and organizations involved in pharmaceutical research, development, manufacture and testing....
- Martindale: The Extra Pharmacopoeia 31
N.B. Listed as "cineole" in some pharmacopoeia.
See also
- CamphorCamphorCamphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel , a large evergreen tree found in Asia and also of Dryobalanops aromatica, a giant of the Bornean forests...
- CitralCitralCitral, or 3,7-dimethyl-2,6-octadienal or lemonal, is either of, or a mixture of, a pair of terpenoids with the molecular formula C10H16O. The two compounds are double bond isomers. The E-isomer is known as geranial or citral A...
- Eucalyptus oilEucalyptus oilEucalyptus 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, antiseptic, repellent, flavouring, fragrance and industrial uses...
- LavenderLavenderThe lavenders are a genus of 39 species of flowering plants in the mint family, Lamiaceae. An Old World genus, distributed from Macaronesia across Africa, the Mediterranean, South-West Asia, Arabia, Western Iran and South-East India...
- MentholMentholMenthol is an organic compound made synthetically or obtained from peppermint or other mint oils. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is -menthol, which is assigned...
- MouthwashMouthwashMouthwash or mouth rinse is a product used to enhance oral hygiene. Some manufacturers of mouthwash claim that antiseptic and anti-plaque mouth rinse kill the bacterial plaque causing cavities, gingivitis, and bad breath. Anti-cavity mouth rinse uses fluoride to protect against tooth decay...
- VaporizerVaporizerA vaporizer or vapouriser is a device used to extract for inhalation the active ingredients of plant material, commonly cannabis, tobacco, or other herbs or blends....
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