The anethole is an organic compound of molecular formula C10H22Or, derived from phenylpropene. It has a characteristic smell of anise oil and a sweet taste. Naturally found in some essential oils.
Essential oils are liquid at room temperature, being responsible for the smell of plants. They are mainly found in plants of the Labiatae family (mint, lavender, thyme and rosemary) and the Umbelliferae (anise and fennel); from the latter, anethole is extracted by steam entrainment.
Anise and fennel are plants that contain anethole, a phenolic ether, which in the case of anise is found in its fruit. This compound is used as a diuretic, carminative, and expectorant. It is also added to food to give them flavor.
It is synthesized by esterification of p-cresol with methyl alcohol, and subsequent condensation with aldehyde. Anethole can be extracted from plants that contain it by steam distillation..
Anethole has toxic effects, and can cause irritation to the skin, eyes, respiratory tract or digestive tract, depending on the site of contact..
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The structure of an anethole molecule is shown in the image above in a spheres and rods model..
Here you can see why it is a phenolic ether: on the right is the methoxy group, -OCH3, and if the CH is ignored for a moment3, you will have the phenolic ring (with a propene substituent) without hydrogen, ArO-. Therefore, in summary form its structural formula could be visualized as ArOCH3.
It is a molecule whose carbon skeleton can be located in the same plane, by having almost all its atoms hybridization sptwo.
Its intermolecular force is of the dipole-dipole type, with the highest electron density located towards the ring region and the methoxy group. Also note the relatively amphiphilic character of anethole: -OCH3 it is polar, and the rest of its structure is apolar and hydrophobic.
This fact explains its low solubility in water, behaving like any fat or oil. It also explains its affinity for other fats present in natural sources..
Anethole can be present in two isomeric forms. In the first image of the structure, the trans (E) form, the most stable and abundant, was shown. Again, this structure is shown in the upper image, but accompanied by its cis (Z) isomer, at the top.
Note the difference between the two isomers: the relative position of -OCH3 with respect to the aromatic ring. In the cis isomer of anethole, -OCH3 is closer to the ring, resulting in steric hindrance, which destabilizes the molecule.
In fact, such is the destabilization, that properties such as the melting point are altered. As a general rule, cis fats have lower melting points, and their intermolecular interactions are less efficient compared to trans fats..
annexol and 1-methoxy-4-propenyl benzene
C10H22OR
White crystals or colorless liquid, sometimes pale yellow.
454.1ºF to 760mmHg (234ºC).
704 ºF (21.3 ºC).
195ºF.
It is practically insoluble in water (1.0 g / l) at 25 ºC.
In a 1: 8 ratio in 80% ethanol; 1: 1 in 90% ethanol.
Miscible with chloroform and ether. It reaches a concentration of 10 mM in dimethyl sulfoxide. Soluble in benzene, ethyl acetate, carbon disulfide, and petroleum ether.
0.9882 g / ml at 20 ° C.
5.45 Pa at 294 ºK.
2.45 x 10-3 Poise.
1,561
Stable, but it is a combustible compound. Incompatible with strong oxidizing agents.
Between 2 and 8 ºC.
7.0.
Anethole trithione (ATT) is attributed numerous functions, including increased salivary secretion, which helps in the treatment of xerostomia.
In anethole, and in the plants that contain it, an activity related to the respiratory system and the digestive system has been demonstrated, in addition to having an anti-inflammatory, anticholinesterase and chemopreventive action.
There is a relationship between the anethole content of a plant and its therapeutic action. Therefore, the therapeutic action is attributed to atenol.
The therapeutic activities of plants that contain anethole make all of them antispasmodic, carminative, antiseptic and expectorant. They also have eupeptic, secretolytic, galactogogic properties and, at very high doses, emenogogic activity..
Anethole has a structural similarity to dopamine, which is why it is pointed out that it can interact with neurotransmitter receptors, inducing the secretion of the hormone prolactin; responsible for the galactogogic action attributed to atenol.
Star anise, a culinary flavoring, is used to treat stomach aches. In addition, it is attributed analgesic, neurotropic and fever-reducing properties. It is used as a carminative and in the relief of colic in children.
Anise is used against aphid insects (aphids), which suck the leaves and shoots causing them to curl.
Anethole acts as an insecticide on the larvae of mosquito species Ochlerotatus caspices Y Aedes egypti. It also acts as a pesticide on the mite (arachnid). It has an insecticidal action on the cockroach species Blastella germanica.
Likewise, it acts on several adult species of weevils. Finally, anethole is a repellent agent for insects, especially mosquitoes..
Anethole acts on the bacteria Enteric salmonella, acting in a bactericidal and bacteriostatic way. Presents antifungal activity, especially on species Saccharomyces cerevisiae Y Candida albicans, the latter being an opportunistic species.
Anethole exerts an anthelmintic action in vitro on the eggs and larvae of the nematode species Haemonchus contortus, located in the digestive tract of sheep.
Anethole, as well as plants that have a high content of the compound, is used as a flavoring in many foods, beverages and confectioneries, due to its pleasant sweet taste. It is used in alcoholic beverages such as ouzo, raki and Pernoud.
Due to its low solubility in water, anethole is responsible for the ouzo effect. When water is added to the ouzo liquor, tiny drops of anethole are formed that cloud the liquor. This is a proof of its authenticity.
It can cause by contact irritation of the eyes and the skin, manifesting in the skin in erythema and edema causing desquamation. By ingestion it can produce stomatitis, a sign that accompanies the toxicity of anethole. While by inhalation there is irritation of the respiratory tract.
Star anise (high in anethole) can cause allergies, especially in babies. Likewise, excessive consumption of anethole can induce the appearance of symptoms, such as muscle spasms, mental confusion and drowsiness due to its narcotic action.
Star anise poisoning increases when used intensively in the form of pure essential oils.
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