A review of extraction methods, geographic variation in chemical composition and identification of marker compounds in bud, leaf and stem clove oil

Abstract

Clove (Syzygium aromaticum) is one of the most precious spices that has been used since ages. Cloves are well-known for their many medicinal properties. It is also widely used in food, flavours and cosmetics industry. One of the main usage of cloves is in the dentistry field to treat bad odour, toothache etc. Though it is native to Indonesia, it has been cultivated in several parts of the world. Clove oil is the richest source of phenolic compounds such as eugenol, eugenyl acetate. It is most powerful source of antioxidant as per oxygen radical absorption capacity. Many review articles had already been published on clove oil which elucidate its morphology, biological and pharmacological benefits. The characteristics of this review study is the exploration and elaborate discussion about extraction methods, discrepancies between the chemical composition due to geographic conditions and identification of marker compounds in leaf, stem and bud clove oil. The comprehensive review revealed that the clove oil mainly consists of phenolic compounds such as eugenol, eugenyl acetate followed by sesquiterpene namely beta-caryophyllene.