Novel benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes: synthesis, characterization and their biological properties

This study was conducted to synthesize and characterize 1,3-dialkyl-5,6-dimethyl-benzimidazolium salts and their silver complexes. Four novel silver(I)-N-heterocyclic carbene complexes were synthesized and characterized by mass analyses, FT-IR and NMR spectroscopy. The biological capacity of the synthesized compounds was evaluated in vitro for their antimicrobial and antitumor activities. The minimum inhibitory concentration (MIC) of the 1,3-dialkyl-5,6-dimethyl-benzimidazolium salts and their complexes was determined for E. coli, P. aeruginosa, S. aureus, C. glabrata and C. albicans in vitro through BMD (Broth Microdilution). The results indicated that silver(I)-NHC complexes exhibit antimicrobial activity. In particular, complex 3c presented a significant broad-spectrum antimicrobial activity. The anticancer properties of the synthesized compounds were evaluated against MCF-7, HCT116, SH-SY5Y and BEAS-2B cell lines. Anticancer activity measurements were carried out according to the Alamar Blue assay. Efficacy was established by comparison of the salts and silver compounds with cisplatin.