Abstract
The benzimidazolium salts 2a-d were synthesized by quaternization of 1-(4-tet-buthylbenzyl) benzimidazole, with the corresponding benzysl bromide. The reactions were carried out in dimethylformamide at 70 °C for 48 h. Therefore, Ag
2
O and benzimidazolium salts 2a-d were reacted in dichloromethane at room temperature under dark and Ag(I)-NHC complex 3 was obtained in very good yields. The Ru(II)-NHC complexes (4a-d) were synthesized via transmetalation reaction from 3a-d. The structures of the obtained compounds were characterized by different spectroscopic techniques such as
1
H and
13
C NMR, elemental analysis, and melting point detection. The lowest MICs values were obtained with the two complexes 4b and 4d. Enzymatic inhibitory investigation against acetylcholinesterase (AChE) and tyrosinase (TyrE), showed that the two complexes 4b and 4d are the most potent inhibitors against (AchE) with an IC
50
of 2.52 and 5.06 µg mL
-1
respectively, and against (TyrE) with an IC
50
of 19.88 and 24.95 µg mL
-1
respectively. Screening of the selected N-Heterocyclic carbene (NHC) ligands (2a-2d) and their respective ruthenium (II) complexes (4a-4d) against colon carcinoma cells lines (HCT-116) and hepatocellular carcinoma cells lines (HepG-2). Furthermore, compounds 2c, 2d, 4b were showed weak cytotoxic action with IC
50
ranging from 13.38 to 18.33 µg in human colon carcinoma cancer cell lines and from 14.36 to 18.45 µg in hepatocellular carcinoma cells lines.