Estragole (''p''-allylanisole, methyl chavicol) is a

phenylpropene Phenylpropenes broadly are compounds containing a phenyl ring bonded to propene, more specifically those with an allyl group bonded to a benzene ring, having the parent structure of allylbenzene. These comprise a class of phenylpropanoids, where ...

, a natural organic compound. Its chemical structure consists of a

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

ring substituted with a

methoxy group In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula . On a benzene ring, the Hammett equation classifies a methoxy substituent at the ''para'' position a ...

and an

allyl In organic chemistry, an allyl group is a substituent with the structural formula . It consists of a methylene bridge () attached to a vinyl group (). The name is derived from the scientific name for garlic, . In 1844, Theodor Wertheim isolated a ...

group. It is an isomer of

anethole Anethole (also known as anise camphor) is an organic compound that is widely used as a flavoring substance. It is a derivative of the aromatic compound allylbenzene and occurs widely in the essential oils of plants. It is in the class of phenylpr ...

, differing with respect to the location of the

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

. It is a colorless liquid, although impure samples can appear yellow. It is a component of various trees and plants, including

turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthine, terebenthene, terebinthine and, colloquially, turps) is a fluid obtainable by the distillation of resin harvested from living trees, mainly pines. Principall ...

(pine oil),

anise Anise (; '), also called aniseed or rarely anix, is a flowering plant in the family Apiaceae native to the eastern Mediterranean region and Southwest Asia. The flavor and aroma of its seeds have similarities with some other spices and herbs, ...

fennel Fennel (''Foeniculum vulgare'') is a flowering plant species in the carrot family. It is a hardy, perennial herb with yellow flowers and feathery leaves. It is indigenous to the shores of the Mediterranean but has become widely naturalized ...

bay A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a ''gulf'', ''sea'', ''sound'', or ''bight''. A ''cove'' is a small, ci ...

tarragon Tarragon (''Artemisia dracunculus''), also known as estragon, is a species of perennial herbaceous plant, herb in the family Asteraceae. It is widespread in the wild across much of Eurasia and North America and is cultivated for culinary and medic ...

, and

basil Basil (, ; , ; ''Ocimum basilicum'' (, )), also called great basil, is a culinary herb of the family Lamiaceae (mints). It is a hardiness (plants), tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" r ...

. It is used in the preparation of fragrances.. The compound is named for ''estragon'', the French name of tarragon.

Production

Hundreds of tonnes of

basil oil Basil (, ; , ; ''Ocimum basilicum'' (, )), also called great basil, is a culinary herb of the family Lamiaceae (mints). It is a tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" refers to the variet ...

are produced annually by steam distillation of ''

Ocimum basilicum Basil (, ; , ; ''Ocimum basilicum'' (, )), also called great basil, is a culinary herb of the family Lamiaceae (mints). It is a hardiness (plants), tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" r ...

'' (common basil). This oil is mainly estragole but also contains substantial amounts of

linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Together with geraniol, nerol, and citronellol, linalool is one of the rose alcohols. Linalool has multiple commercial app ...

. Estragole is the primary constituent of

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

(comprising 60–75%). It is also present in

pine oil Pine oil is an essential oil obtained from a variety of species of pine, particularly ''Pinus sylvestris''. Typically, parts of the trees that are not used for lumber stumps, etc. are ground and subjected to steam distillation. As of 1995, sy ...

(2%),

frankincense Frankincense, also known as olibanum (), is an Aroma compound, aromatic resin used in incense and perfumes, obtained from trees of the genus ''Boswellia'' in the family (biology), family Burseraceae. The word is from Old French ('high-quality in ...

(4%), ''

Clausena anisata :''Should not be confused with syzygium anisatum, a tree native to eastern Australian rainforests, used as a culinary herb.'' ''Clausena anisata'' ( Willd.) Hook.f. ex Benth. is a deciduous shrub or small tree, belonging to the Rutaceae or Cit ...

'', and ''

Syzygium anisatum ''Syzygium anisatum'', with common names ringwood and aniseed tree, is a rare rainforest tree native to New South Wales, Australia. The aromatic leaves contain an essential oil profile comparable to true aniseed. The leaf from cultivated plant ...

''. Estragole is used in perfumes and in

flavoring A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive that is used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of ...

s for foods. In the European Union, it can only be present in a flavor by using an essential oil. Upon treatment with

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

, estragole converts to

. Estragole is used in the synthesis of

magnolol Magnolol is an organic compound that is classified as lignan. It is a bioactive compound found in the bark of the Houpu magnolia ('' Magnolia officinalis'') and in '' M. grandiflora''. Magnolol is a compound that acts on GABA_A receptors and fu ...

Safety

Estragole is suspected to be

carcinogenic A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and Biological agent, biologic agent ...

and

genotoxic Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with mutagenicity, all mutagens are genotoxic, but some genotoxic s ...

, as is indicated by a report of the European Union

Committee on Herbal Medicinal Products The Committee on Herbal Medicinal Products (HMPC), is the European Medicines Agency's committee responsible for elaborating the agency's opinions on herbal medicines. Role HMPC aims at assisting in the harmonization of procedures and provisions co ...

. Several studies have clearly established that the profiles of metabolism, metabolic activation, and covalent binding are dose dependent and that the relative importance diminishes markedly at low levels of exposure (that is, these events are not linear with respect to dose). In particular,

rodent studies Rodents have been employed in biomedical experimentation from the 1650s. Rodent studies up to the early 19th century were mainly physiological or toxicological. The first rodent behavioral study was carried out in 1822, a purely observational st ...

show that these events are minimal probably in the dose range of 1–10 mg/kg body weight, which is approximately 100 to 1,000 times the anticipated human exposure to this substance. For these reasons it is concluded that the present exposure to estragole resulting from consumption of herbal medicinal products (short time use in adults at recommended posology) does not pose a significant cancer risk. In the meantime exposure of estragole to sensitive groups such as young children, pregnant and breastfeeding women should be minimized. The

Scientific Committee on Food The Scientific Committee on Food (SCF), established in 1974, was the main committee providing the European Commission with scientific advice on food safety. "Scientific Committee on Food - FOOD STANDARDS AGENCY" (overview), Gov.uk, F ...

from the

Health and Consumer Protection Directorate Health has a variety of definitions, which have been used for different purposes over time. In general, it refers to physical and emotional well-being, especially that associated with normal functioning of the human body, absent of disease, pain ...

of the

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

took a more concerned position and concluded that "Estragole has been demonstrated to be genotoxic and carcinogenic. Therefore the existence of a threshold cannot be assumed and the Committee could not establish a safe exposure limit. Consequently, reductions in exposure and restrictions in use levels are indicated."

References

External links

Opinion by the Scientific Committee on Food of the European Union on Estragole
{{Phenylpropene Food additives Perfume ingredients Phenylpropenes 4-Methoxyphenyl compounds Allyl compounds O-methylated natural phenols

Production

Safety

See also

References

External links