ABSTRACT
Medicinal plants serve as a huge reservoir of novel phytoconstituents that can be employed to control the alarming status of diseases. Clove is a plant-based spice that has been employed for the cure of several fatal disorders since ancient times. The clove is collected mainly from the flower buds that are dried to develop whole clove buds. The other byproducts of clove are ground clove, volatile oil, stem or leaf, and oleoresins. Clove oleoresin (COR) is a green-brownish liquid isolated from the buds of clove. Supercritical carbon dioxide extraction, solvent extraction and microwave-assisted extraction are major techniques used for refining clove. Clove oils and oleoresins are being valued for their wide range of properties like antibacterial, antimicrobial, cardioprotective, antiviral, anticancer, and immunomodulatory. It contains major secondary metabolites belonging to terpenoids and phenols. The major bioactive components present in clove oil are eugenol, O-acetyleugenol, 4-allyl-2-methoxyphenyl acetate, and trans-caryophyllene. These phenolic constituents have enormous antioxidant and antimicrobial potential, which enhances the bioactivities of clove spices. This review aims to examine the extraction and characterization methods, phytochemical composition, and pharmacological applications of clove extracts.
