Preparation, Spectral Characterization and Anticancer Potential of Cinnamic Esters

Cinnamic acid and its derivatives show a remarkable variety of biological activities and are often studied in search of the development of new and highly effective drugs. This work aims to synthesize, characterize and evaluate the cytotoxic activity of esters derived from cinnamic acid. Eighteen esters were synthesized through Steglich’s esterification, of which eleven were not reported in the literature. All compounds were fully characterized by Fourier transform infrared epectroscopy (FTIR), nuclear magnetic resonance (1H and 13C NMR) and high-resolution mass spectrometry (HRMS) data. The cytotoxic activity of esters obtained was evaluated using four human tumor cell lines: SNB-19 (astrocytoma), HCT-116 (colon carcinoma, human), PC3 (prostate) and HL60 (promyelocytic leukemia) through the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) colorimetric assay. These studies showed that the compound 3-methoxybenzyl (E)-3-(4-methoxyphenyl)acrylate (12) is the most potent against HCT-116, PC3 and SBN-19 cells, with the lowest half maximal inhibitory concentration (IC50) value of 16.2 µM in the HCT-116 strain. The derivatives were obtained in good yields (76.6-95%), except for compounds 5-isopropyl-2-methylphenyl (E)-3-(3-hydroxy-4-methoxyphenyl)acrylate (17) (18.6%) and 2-isopropyl-5-methylphenyl (E)-3-(3-hydroxy-4-methoxyphenyl)acrylate (18) (15.5%).