A series of 3′,4′,5′-trimethoxy flavonoids with benzimidazole linked by different chain alkanes have been designed and synthesized. The potential activity of these compounds as anti-tumor agents was evaluated by cytotoxicity assay in MGC-803 (human gastric cancer), MCF-7 (human breast cancer), HepG-2 (human hepatoma) and MFC (mouse gastric cancer) tumor cell lines. Among them, compound 15 7-(3-(2-chloro-1H-benzo[d]imidazol-1-yl)propoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one displayed the most potent antiproliferative activity, with IC5...