Synthesis and investigation of antiproliferative activity of Ru-NHC complexes against C6 and HeLa cancer cells

The 2-methylpyridine, 2-diethylaminoethyl, and isopentyl linked a series of symmetric and unsymmetric benzimidazolium salts 2a–e were prepared and used in the synthesis of silver-N-heterocyclic carbene (NHC) complexes (3a–e). The Ru(II)-NHC complexes (4a–h) were synthesized via transmetalation reaction from 3a–e. 4a–h complexes were converted to Ru(II)-NHC.HCl complexes (5ah) by HCl solution of diethyl ether and characterized by different spectroscopic techniques such as (1)H and (13)C NMR, LC/MS-Q-TOF, FT-IR, elemental analysis, and melting point detection. We examined the effect of the structural difference of complexes on anticancer activity via different arenes and metal centers. Antiproliferative activity of 5a–h and 3a was tested against human cervix adenocarcinoma (HeLa) and rat glioblastoma (C6) cell lines by ELISA assay. The IC(50) value of 5b, 5c and 5e complexes exhibited good cytotoxic activity than cisplatin on C6 (14.2 ± 0.5 mM; 16.2 ± 0.4 mM; 24.2 ± 0.7 mM, respectively) and HeLa (11.1 ± 0.5 mM; 13.7 ± 0.3 mM; 22.8 ± 0.8 mM, respectively) cell lines.