Analysis of antimicrobial activity and biofilm inhibition of Ag-NHC complexes by in-vitro and molecular docking method.

Abstract

Aims: Metal-N-heterocyclic carben (NHC) complexes have garnered significant attention from synthesis chemistry. Silver is well known for its broad-spectrum antimicrobial activity, and it exhibits their activities with different mechanisms. In this study, we combined these two important scaffolds, analyzed for possible antimicrobial and antibiofilm activity, and evaluated the interactions against DNA Gyrase, SarA, Human Serum Albumin, and DNA for getting insight into the antimicrobial and antibiofilm details.

Materials & methods: Four new Ag-NHC complexes (2a-d) were prepared from corresponding benzimidazolium salts (1a-d) and revealed by elemental analysis, FT-IR, NMR, LC-MS, and HRMS. The antimicrobial and antibiofilm properties of both ligands and complexes were evaluated with in-vitro and molecular docking methods which were performed against DNA Gyrase, SarA, Human Serum Albumin, and DNA.

Results and conclusions: 1d showed superior activity while 2a and 2d were effective against C. albicans, with activity comparable to fluconazole in the range of 8.6-8.7 µM. The highest binding affinity was recorded for 2a as -7.93 kcal/mol against DNA Gyrase, while 2b has the best interactions with -5.49 kcal/mol against SarA. and -7.74 kcal/mol binding affinity was determined for 2a with molecular docking. All the molecules interacted with the same grove of DNA.