Cytotoxic activity of new acetoxycoumarin derivatives in cancer cell lines

Coumarin and their derivatives are important and useful compounds with diverse pharmacological properties. In the present study, we evaluated the in vitro cytotoxic activity of new acetoxycoumarin derivatives: 4-(7-methoxy-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (1), 4-(1-methyl-3-oxo-3H-benzo[f]chromen-2-yl)phenyl acetate (2), 4-(6-propionamido-4-methyl-2-oxo-2H-chromen-3-yl) phenyl acetate (3), 4-(7-acetoxy-2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (4), 4-(2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (5), 4-(6-bromo-2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (6), 4-(7-(diethylamino)-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (7), 4-(6,8-dibromo-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (8) against A549 human lung cancer, CRL 1548 rat liver cancer and CRL 1439 normal rat liver cells.

The cytotoxic activity was evaluated by crystal violet dye-binding assay. The effect of compounds 5 and 7 on different phases of the cell cycle was determined using flow cytometry.

In the A549 lung cancer cell line, the 50% lethal dose (LD50) values for compounds 1-4, 6 and 8 were found to be >100 μM while those for 5 and 7 were 89.3 and 48.1 μM, respectively after 48 h treatment. In the CRL 1548 liver cancer cell line, only compound 7 showed toxicity, with an LD50 of 45.1 μM. Compounds 5 and 7 caused different cell phase arrest in lung and liver cancer cell lines.

The results indicate that 4-(7-(diethylamino)-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (7) had the highest cytotoxic activity in all of the examined cell lines.