Synthesis and antitumor activity of novel hybrid compounds between 1,4‐benzodioxane and imidazolium salts

A series of novel hybrid compounds between 1,4-benzodioxane and imidazolium salts was designed and prepared. The compounds were evaluated in vitro against a panel of human tumor cell lines (K562, SMMC-7721, and A-549). The structure-activity relationship results demonstrated that the 2-methyl-benzimidazole or 5,6-dimethyl-benzimidazole ring and substitution of the imidazolyl-3-position with a 4-phenylphenacyl substituent were critical for promoting cytotoxic activity. Particularly, compound 25 was found to be the most potent compound with IC50 values of 1.06-8.31 μM against the three human tumor cell lines and exhibited higher selectivity to K562 and SMMC-7721 cells with IC50 values 4.5- and 4.7-fold lower than cisplatin. Moreover, compound 25 inhibited cell proliferation by inducing the G0/G1 cell cycle arrest and apoptosis in SMMC-7721 cells.