Eugenol compound in cloves

Eugenol (4-allyl-2-methoxyphenol) is the major constituent [70% to 90%] in the aromatic oil extract from cloves, a spice widely used as a flavoring for meats, stews, cakes and teas. Prominent sources of eugenol are clove, cinnamon, tulsi and pepper.

Syzygium aromaticum commonly known as clove, is an median size tree (8-12 m) from the Mirtaceae family native from the Maluku islands in east Indonesia.

Cloves are now grown in several tropical regions and the spice sold as intact flower buds or as a ground powder. This plant represents one of the richest sources of phenolic compounds such as eugenol, eugenol acetate and gallic acid and posses great potential for pharmaceutical, cosmetic, food and agricultural applications.

Clove oils including eugenol have been claimed to have gentle local anesthetic and antiseptic activities and previously were commonly used in dentistry. Eugenol and clove extracts have also been purposed to be beneficial for gastrointestinal complaints such as nausea, diarrhea, abdominal pain and for cough, phlegm and chest congestion. Eugenol has been approved to encompass numerous beneficial aspects against a capacious spectrum of life-threatening indispositions including oxidative stress, inflammation, hyperglycemia, elevated cholesterol level, neural disorders and cancer. In addition, eugenol has also shown strong potential as an antimicrobial agent against wide ranges of pathogenic and spoilage causing microorganisms.

Eugenol is the main bioactive compound of clove, which is found in concentrations ranging from 9 381.70 to 14 650.00 mg per 100 g of fresh plant material.

Clove buds contain 15 to 20 % of oil by weight. The main oil constituents are eugenol (70–95 %), eugenol acetate (up to 20 %) and β-caryophyllene (12–17 %). The oil also contains about 10% acetyleugenol and small quantities of gallic acid, sesquiterpenes, furfural, vanillin, and methyl-n-amyl ketone.

Clove stem oil comprises 5–7 % of oil by weight, the major component being eugenol (90–95 %), while eugenyl acetate and β-caryophyllene and others are present in smaller amounts.

Various extraction methods have been practiced globally for the extraction of eugenol and other nutraceutics from plants. The most extensively employed approaches in this regard include solvent extraction, hydro-distillation, microwave-assisted extraction, supercritical carbon dioxide extraction and ultrasound-based extraction.
Eugenol compound in cloves

Clove oils

Clove oil is an essential oil that’s derived from clove trees. The clove tree, known as Syzygium aromaticum, is native to Southeast Asia. The clove tree is a tropical evergreen species that produces thousands of small, fragrant flower buds.

Picked by hand in late summer and again in winter, the buds are dried until they turn brown. The buds are then left whole, ground into a spice or are steam-distilled to produce concentrated clove essential oil.

Clove oil is produced by distilling the dried flower buds. Other parts of the tree, such as the stem and leaves, may also be used. Clove oil also can be extracted through cold pressing.

Clove oil is colorless or pale yellow and has a strong, spicy aroma, has been used for centuries in a variety of applications. Clove oil is a mixture of different compounds, with the three main active ingredients being eugenol, eugenyl acetate and caryophyllene.

Clove oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. Clove oil uses range from dulling pain and improving blood circulation to reducing inflammation and acne.

One of the best-known clove oil uses is helping combat dental problems, such as toothaches. Eugenol, cloves principal constituent was used in the dental industry for years to numb gums. Eugenol acts as an anesthetic and antibacterial agent.

Clove oil also showed fungicidal activity against several plant pathogenic fungi such as Fusarium solani, Phythopthora capsici, Sclerotium rolfsii, Rigidoporus lignosus, Colletotrichum, Pseudomonas solanacearum, and nematodes.

Clove oil was reported as an inhibitor of platelet aggregation and thromboxane synthesis and may act as an antithrombotic agent.
Clove oils