Antiproliferative activities of 2-hydroxyethyl substituted benzimidazolium salts and their palladium complexes against human cancerous cell lines

Benzimidazolium salts (1a and 1b) and respective palladium complexes (2a and 2b) were prepared and characterized with H-1 and C-13 NMR, IR, elemental analysis as well as HRMS (for 2a). All target compounds were screened as potential anticancer agents against human cell lines for assessing their cytotoxicity. Heterocyclic organic compounds (1a and 1b) showed more cytotoxic activity than their complexes (2a and 2b) in the tested two cell lines. Particularly, a benzimidazolium salt including a 4-methylbenzyl group had a high cytotoxic potency towards MDA-MB-231 and DLD-1 cell lines with IC50 values comparable to a well-known anticancer drug cisplatin, which is generally used in clinical studies. Furthermore, a compound namely 1-(2-hydroxyethyl)-3-(2,3,4,5,6-pentamethylbenzyl)-1H-benzo[d]imidazol-3-ium bromide was found to be more cytotoxic activity in MDA-MB-231 cell line compared to cisplatin with following IC50 value of 7.59 +/- 0.68 mu M.