Elemicin 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 In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

, and is a constituent of several plant species'

essential oils 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 ...

Natural occurrence

Elemicin is a constituent of the

oleoresin Oleoresins are semi-solid extracts composed of resin and essential or fatty oil, obtained by evaporation of the solvents used for their production. The oleoresin of conifers is known as crude turpentine or gum turpentine, which consists of oil of ...

and the essential oil of ''

Canarium luzonicum ''Canarium luzonicum'', commonly known as elemi, is a tree native to the Philippines. The oleoresin harvested from it is also known as elemi. Synonyms * ''Canarium carapifolium'' G.Perkins * ''Canarium oliganthum'' Merr. * ''Canarium polyanthu ...

'' (also referred to as elemi). Elemicin is named after this tree. One study found it to compose 2.4% of the fresh essential oil. Elemicin is also present in the oils of the spices

nutmeg Nutmeg is the seed or ground spice of several species of the genus ''Myristica''. ''Myristica fragrans'' (fragrant nutmeg or true nutmeg) is a dark-leaved evergreen tree cultivated for two spices derived from its fruit: nutmeg, from its seed, an ...

and mace, with it composing 2.4% and 10.5% of those oils respectively. Structurally, elemicin is similar to myristicin, differing only by myristicin's methyl group that joins the two oxygen atoms that make up its dioxymethy moiety, with both constituents being found in nutmeg and mace.

Isolation

Elemicin was first isolated from elemi oil using

vacuum distillation Vacuum distillation is distillation performed under reduced pressure, which allows the purification of compounds not readily distilled at ambient pressures or simply to save time or energy. This technique separates compounds based on differences i ...

. Specifically, the substance was collected between 162-165 °C at a reduced pressure of 10

torr The torr (symbol: Torr) is a unit of pressure based on an absolute scale, defined as exactly of a standard atmosphere (). Thus one torr is exactly (≈ ). Historically, one torr was intended to be the same as one " millimeter of merc ...

Preparation

Elemicin has been synthesized from

syringol Syringol is the organic compound with the formula HO(CH3O)2C6H3. The molecule is a phenol, with methoxy groups in the flanking (2 and 6) positions. It is the symmetrically dimethylated derivative of pyrogallol. It is a colorless solid, althou ...

and

allyl bromide Allyl bromide (3-bromopropene) is an organic halide. It is an alkylating agent used in synthesis of polymers, pharmaceuticals, synthetic perfumes and other organic compounds. Physically, allyl bromide is a colorless liquid with an irritating and p ...

using

Williamson ether synthesis The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol (alkoxide). This reaction was developed by Alexander Williamson in 1850. Typically it involves the reaction of an alkoxide io ...

and

Claisen rearrangement The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a ,3sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, ...

. The

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic n ...

entering the ''para''-position was made possible by secondary

Cope rearrangement The Cope rearrangement is an extensively studied organic reaction involving the ,3sigmatropic rearrangement of 1,5-dienes. It was developed by Arthur C. Cope and Elizabeth Hardy. For example, 3-methyl-hexa-1,5-diene heated to 300 °C yield ...

. This is due to syringol's allyl

aromatic In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...

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 be ...

being blocked by ethers in both ''ortho''-positions. When blocked the allyl group migrates to the ''para''-position, in this case with yields above 85%.

Uses

Elemicin has been used to synthesize the proto-

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

mescaline.

Pharmacology

Raw nutmeg causes

anticholinergic Anticholinergics (anticholinergic agents) are substances that block the action of the neurotransmitter called acetylcholine (ACh) at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous sys ...

-like effects, which are attributed to elemicin and myristicin. Elemicin inhibits Stearoyl-CoA Desaturase 1 (SCD1) by metabolic activation. Elemicin is one of the main components in aromatic food and has antimicrobial, antioxidant, and antiviral activities. Elemicin possesses genotoxicity and carcinogenicity. Excess consumption of raw nutmeg results in delirium and disorientation.

References