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

phenylpropene Phenylpropene is the organic compound with the formula C6H5CH2CH=CH2. It is a colorless liquid. The compound consists of a phenyl group attached to allyl. Phenylpropene isomerizes to trans-propenylbenzene. In plant biochemistry, the phenylpro ...

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

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms ...

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 ...

and an

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

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 phenylpropene, a type of aromatic compound that occurs widely in nature, in essential oils. It is in the class of phe ...

, 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 betwee ...

. 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, terebenthene, terebinthine and (colloquially) turps) is a fluid obtained by the distillation of resin harvested from living trees, mainly pines. Mainly used as a special ...

(pine oil),

anise Anise (; '), also called aniseed or rarely anix is a flowering plant in the family Apiaceae native to Eurasia. The flavor and aroma of its seeds have similarities with some other spices and herbs, such as star anise, fennel, licorice, and t ...

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, circular bay with a na ...

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

, and basil. 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 are produced annually by steam distillation of '' Ocimum basilicum'' (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. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of ...

. 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 o ...

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

(2%), ''

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 Ci ...

'' and ''

Syzygium anisatum :''Should not be confused with Clausena anisata, a small tree native to Southeast Asia and Australia.'' ''Syzygium anisatum'', with common names ringwood and aniseed tree, is a rare Australian rainforest tree with an aromatic leaf that has an ...

''. Estragole is used in perfumes and is restricted in flavours as a biologically active principle: it can only be present in a flavour 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 exp ...

, estragole converts to

. A known use of estragole is in the synthesis of magnolol.

Safety

Estragole is suspected to be

carcinogenic A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive sub ...

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 con ...

.EMEA/HMPC/137212/2005, Committee on Herbal Medicinal Products. Final Public Statement on the Use of Herbal Medicinal Products Containing Estragole http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2010/04/WC500089960.pdf 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 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 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."SCF/CS/FLAV/FLAVOUR/6, 26 September 2001, Opinion of the Scientific Committee on Food on Estragole (1-Allyl-4-methoxybenzene)

References

External links

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

Production

Safety

See also

References

External links