Synthesis, Characterization And Biological Activities Of Eugenol And Thymol Derivatives

Abstract

Drug development based on natural product especially on monoterpene and phenylpropanoid becomes a subject of interest due to their simple skeletal structures. Therefore, 18 derivatives were synthesized which comprise of 14 eugenol derivatives and five thymol derivatives with seven of them were considered new. These derivatives were synthesized via structural modification at hydroxyl group furnishing ether and ester derivatives in the presence of base. Each derivative was characterized by normal spectroscopic techniques of FTIR, UV-Vis, NMR and MS. The spectroscopic data of FTIR showed few significance peaks which corresponds to v(=CH), v(C-H), v(C=C)aromatic and v(C-O) stretches appeared for both derivatives at the range of 3092-2960 cm -1 -1 , 1600 cm and 1455-1256 cm -1 ; and additional stretch of v(C=O) around 1700 cm -1 for ester derivatives. The absorption band in the UV-Vis spectra for aromatic moiety as π→π electronic transition was observed in both ether and ester derivatives. Meanwhile, additional band was observed in UV-Vis spectra for ester derivatives indicating the presence of n→π transition depicts the C=O moiety. In the NMR spectra analysis, the presence of methylene protons around δH 5.00 ppm in 1 H NMR spectra and the appearance of C=O peak at δC 160 ppm in 13 C NMR confirmed the ether and ester linkages. The structures of the derivatives were also confirmed by MS analysis where peaks in the form of ion [M] + obtained in m/z values were in agreement with the expected molecular weight of the synthesized compound.