Eugenol is a
phenylpropenePhenylpropenes, propenylphenols or allylbenzenes are a class of phenylpropanoids, a type of polyphenols.The phenylpropenes, including eugenol, chavicol, safrole and estragole, are derived from the monolignols. These compounds are the primary constituents of various essential oils....
, an allyl chain-substituted
guaiacolGuaiacol is a naturally occurring organic compound with the formula C6H4. Although it is biosynthesized by a variety of organisms, this colorless aromatic oil is usually derived from guaiacum or wood creosote. Samples darken upon exposure to air and light. Guaiacol is present in wood smoke,...
. Eugenol is a member of the
phenylpropanoidThe phenylpropanoids are a diverse family of organic compounds that are synthesized by plants from the amino acid phenylalanine. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of cinnamic acid, which is synthesized from phenylalanine in the first...
s class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain
essential oilAn 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 especially from
cloveCloves are the aromatic dried flower buds of a tree in the family Myrtaceae. Cloves are native to the Maluku islands in Indonesia and used as a spice in cuisines all over the world...
oil,
nutmegThe nutmeg tree is any of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, an evergreen tree indigenous to the Banda Islands in the Moluccas of Indonesia...
,
cinnamonCinnamon is a spice obtained from the inner bark of several trees from the genus Cinnamomum that is used in both sweet and savoury foods...
,
basilBasil, 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....
and
bay leafBay 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...
. It is slightly soluble in water and soluble in organic
solventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
s. It has a spicy, clove-like aroma.
The name is derived from the scientific name for
cloveCloves are the aromatic dried flower buds of a tree in the family Myrtaceae. Cloves are native to the Maluku islands in Indonesia and used as a spice in cuisines all over the world...
,
Eugenia aromaticum or
Eugenia caryophyllata. Eugenol is responsible for the aroma of cloves. It is the main component in the
essential oilAn 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...
extracted from cloves, comprising 72–90% of the total.
Modern uses
Eugenol is used in
perfumePerfume is a mixture of fragrant essential oils and/or aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces "a pleasant scent"...
ries, flavorings, essential oils and in medicine as a local
antisepticAntiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
and anesthetic. It is a key ingredient in
IndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n
kretek (clove)Kretek are cigarettes made with a blend of tobacco, cloves and other flavors. The word "kretek" itself is an onomatopoetic term for the crackling sound of burning cloves. Haji Jamahri, a resident of Kudus, Java, created kreteks in the early 1880s as a means to deliver the eugenol of cloves to the...
cigaretteA cigarette is a small roll of finely cut tobacco leaves wrapped in a cylinder of thin paper for smoking. The cigarette is ignited at one end and allowed to smoulder; its smoke is inhaled from the other end, which is held in or to the mouth and in some cases a cigarette holder may be used as well...
s. It was used in the production of
isoeugenolIsoeugenol is a phenylpropene, a propenyl-substituted guaiacol. A phenylpropanoid, it occurs in the essential oils of plants such as ylang-ylang . It can be synthesized from eugenol and had been used in the manufacture of vanillin. It may occur as either the cis or trans isomer...
for the manufacture of
vanillinVanillin is a phenolic aldehyde, an organic compound with the molecular formula C8H8O3. Its functional groups include aldehyde, ether, and phenol. It is the primary component of the extract of the vanilla bean. It is also found in Leptotes bicolor, roasted coffee and the Chinese red pine...
, though most
vanillinVanillin is a phenolic aldehyde, an organic compound with the molecular formula C8H8O3. Its functional groups include aldehyde, ether, and phenol. It is the primary component of the extract of the vanilla bean. It is also found in Leptotes bicolor, roasted coffee and the Chinese red pine...
is now produced from
phenolPhenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
or from
ligninLignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants and some algae. The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum, meaning wood...
.
Eugenol can be combined with
zinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
to form a material - known as
zinc oxide eugenolZinc oxide eugenol is a material created by the combination of zinc oxide and eugenol contained in oil of cloves. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence metal salts. ZOE can be used as...
- which has
restorativeA dental restoration or dental filling is a dental restorative material used to restore the function, integrity and morphology of missing tooth structure. The structural loss typically results from caries or external trauma. It is also lost intentionally during tooth preparation to improve the...
and
prosthodonticProsthodontics, also known as dental prosthetics or prosthetic dentistry, is one of nine dental specialties recognized by the American Dental Association, Royal College of Dentists of Canada, and Royal Australasian College of Dental Surgeons...
applications in
dentistryDentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered...
.
Eugenol derivatives or methoxyphenol derivatives in wider classification are used in perfumery and flavoring. They are used in formulating insect attractants and UV absorbers, analgesics,
biocideA biocide is a chemical substance or microorganism which can deter, render harmless, or exert a controlling effect on any harmful organism by chemical or biological means. Biocides are commonly used in medicine, agriculture, forestry, and industry...
s, and
antisepticAntiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
s. They are also used in manufacturing stabilizers and
antioxidantAn antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
s for
plasticA plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
s and
rubberNatural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
s. Attempts have been made to develop eugenol derivatives for intravenous injection, such as
propanididPropanidid is an ultra short-acting phenylacetate general anesthetic. It was originally introduced by Bayer in 1963 but anaphylactic reactions caused it to be withdrawn shortly afterwards....
and G.29.505. The latter produced unacceptable side effects around the site of injection in many patients.
It 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. It also attracts female cucumber beetles.
Clove oil is growing in popularity as an anaesthetic for use on aquarium fish as well as on wild fish when sampled for research and management purposes where, readily available over-the-counter from pharmacies, it may be a humane method to euthanise sick and diseased fish either by direct over-dose or to induce sleep before an overdose of ethanol.
It is also used in some mousetraps.
Eugenol kills certain human colon cancer cell lines
in vitroIn 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...
.
Toxicity
Eugenol is
hepatotoxicHepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...
, meaning it may cause damage to the
liverThe liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
.
Overdose is possible, causing a wide range of symptoms from blood in the patient's urine, to
convulsionA convulsion is a medical condition where body muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body. Because a convulsion is often a symptom of an epileptic seizure, the term convulsion is sometimes used as a synonym for seizure...
s,
diarrheaDiarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
,
nauseaNausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
,
unconsciousnessUnconsciousness is the condition of being not conscious—in a mental state that involves complete or near-complete lack of responsiveness to people and other environmental stimuli. Being in a comatose state or coma is a type of unconsciousness. Fainting due to a drop in blood pressure and a...
,
dizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, or rapid
heartbeatHeart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
. A 2-year old boy nearly died after taking between 5 and 10 ml., according to a published 1993 report.
Some fragrances should be avoided by people with eugenol allergy. An example would be
KourosYves Saint Laurent or YSL is a luxury fashion house founded by Yves Saint Laurent and his partner, Pierre Bergé. Today, its chief designer is Stefano Pilati. Yves Saint Laurent, founder of the brand, died in 2008.-History:...
eau de toilette by
Yves Saint LaurentYves Saint Laurent or YSL is a luxury fashion house founded by Yves Saint Laurent and his partner, Pierre Bergé. Today, its chief designer is Stefano Pilati. Yves Saint Laurent, founder of the brand, died in 2008.-History:...
. Eugenol may cause allergic contact
dermatitis-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
.
List of plants that contain the chemical
- Cloves (Syzygium aromaticum)
- Cinnamon
Cinnamon is a spice obtained from the inner bark of several trees from the genus Cinnamomum that is used in both sweet and savoury foods...
- Cinnamomum tamala
- Nutmeg (Myristica fragrans)
- Ocimum basilicum – Sweet Basil
- Ocimum gratissimum
Ocimum gratissimum, also known as Clove Basil, African Basil, and in Hawaii as Wild Basil, is a species of Ocimum. It is naturalized in Hawaii.-Pharmacology of extracts and essential oils:...
– African Basil
- Ocimum tenuiflorum (Ocimum sanctum) – Tulsi or Holy Basil
- Japanese star anise
Illicium anisatum, commonly known as the Japanese star anise, is a tree similar to Chinese star anise. It is highly toxic, therefore it is not edible; instead, it has been burned as incense in Japan, where it is known as...
- Lemon balm
Lemon balm , not to be confused with bee balm, Monarda species, is a perennial herb in the mint family Lamiaceae, native to southern Europe and the Mediterranean region....
- Dill
Dill is a perennial herb. It is the sole species of the genus Anethum, though classified by some botanists in a related genus as Peucedanum graveolens C.B.Clarke.-Growth:...
External links
- Kegley, S.E., Hill, B.R., Orme S., Choi A.H., Toxicity Information for Eugenol in PAN Pesticide Database, Pesticide Action Network, North America (San Francisco, CA, 2010) (Eugenol entry on the Molecule of the Day blog)