Antiproliferative assay results indicated that compounds 6o and 6u exhibited the most potent activity against gastric cancer cell SGC-7901, which was more potent than the positive control. Especially, compound 6o exhibited significant telomerase inhibitory activity (IC 50 = 2.3 ± 0.07 μM), which was comparable to the positive control ethidium bromide. Docking simulation was performed to position compound 6o into the active site of telomerase (3DU6) to determine the probable binding model.