New silver N[sbnd]heterocyclic carbenes complexes: Synthesis, molecular docking study and biological activities evaluation as cholinesterase inhibitors and antimicrobials

Abstract

We focused our study for the conception and the synthesis of a new series of Silver (I) N-heterocyclic carbene complexes which were obtained from the corresponding N-heterocyclic carbene (NHC) precursors and their unsymmetrical benzimidazolium salts. These new Ag-NHC complexes were screened for their antibacterial, antifungal, and anti-cholinesterase activities. The biological activities of synthesized products were compared with standard drugs. N-heterocyclic carbenes 2a-f and complexes 3a-f exhibited moderate antibacterial and antifungal activities. The results proved that the compounds indicated moderate to excellent activity against both AChE and BuChE. It was found that most of the complexes displayed good AChE and BuChE inhibitory activities. In particular, compounds 3c and 3e were the most potent inhibitors in the series with IC50 values of 8.56 ± 1.17 μM and 5.05 ± 0.30 μM against AChE and BChE, respectively. Docking studies revealed that compounds 3c and 3e bind manly to the catalytic anionic site (CAS) of the AChE, and BChE respectively.