Isolation and Characterization of Eugenol from Clove Bud Oil

Eugenol is a colorless to pale yellow, aromatic oily liquid extracted from some essential oilsfrom nutmeg, clove oil, basil, bay leaf and cinnamon (Bhuiyan et al., 2010). It is an ingredient of many products in the pharmaceutical, food and cosmetic industry. The eugenol derivatives are applied in medicine as a local antiseptic and anesthetic. The wide range of eugenol biological activities includes antimicrobial, anti-inflammatory, analgesic and antioxidant. However, high eugenol concentrations have been reported to be cytotoxic and when applied to the pulp tissues results in tissue damage (Khalil et al., 2017).

Eugenol is preferably extracted from its botanical sources since it is present in high concentrations some plants, 80–90% in clove bud oil and 82–88% in clove leaf oil.It is therefore economical to isolate from natural sources compared to synthetic routes which use expensive chemicals and complex workup procedures (Nejad et al., 2017).

Gas chromatography (GC) is used to separate the different constituents of a mixture, determining the relative amounts of each constituent test the purity of each substance and help to identify the compounds. The NMR spectra are highly predictable for small molecules and well-resolved. The different functional groups of a compound are distinguishable, and similar functional groups with differing neighboring groups afford different NMR signals. This method is non-destructive, ideal for analyzing and recovering small samples (Khalil et al., 2017).

On the other hand, Infrared spectroscopy (IR) is utilized in determining the functional groups in a molecule, determine its purity and also identify compounds by fingerprinting the IR spectrum. It is usually used together with NMR spectroscopy to determine the structure of compounds. This GC and IR methods of analysis are cheaper and faster compared to NMR spectroscopy (Bhuiyan et al., 2010).

Conclusion

Eugenol was successfully isolated in high yields and characterized by using spectroscopic techniques. In GC analysis it was identified by comparing its retention index with that of an authentic sample. The isolated eugenol had a retention time of 10.054 of compared to that of the authentic sample of 9.810. The isolated eugenol was yellow in color and it had its characteristic color.

Works Cited 

Bhuiyan N.I., Begum J., Nandi N.C. and Akter F.(2010). Constituents of the essential oil from leaves and buds of clove (Syzygium caryophyllatum

(L.) Alston). African Journal of Plant Science Vol. 4(11), pp. 451-454.

Khalil A.A, Rahman U., Khan M.R., Sahar A., Mehmood T., Khan M. (2017). Essential oil eugenol: sources, extraction techniques, and nutraceutical perspectives. RSC Adv., 2017, 7,

32669-32681.

Nejad S.M, Ozguneş H., Basaran N.(2017). Pharmacological and Toxicological Properties of Eugenol. Turk J Pharm Sci  14(2).