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
