Synthesis, antimicrobial and antibiofilm activities of silver(I) complexes with N-alkylbenzimidazole derivatives and their protein interaction modelling study

Abstract

• Synthesis of bis(N-alkylbenzimidazole)silver(I) nitrate. • Antimicrobial activities. • Antibiofilm activities. • Molecular docking study to understand the mechanisms of action. This study investigates the antimicrobial and antibiofilm potential of three silver(I) complexes derived from N -alkylbenzimidazole derivatives: bis[( Z )-1-styryl-benzimidazole]silver(I) nitrate ( 4 ), bis[( E )-1-styryl-benzimidazole]silver(I) nitrate ( 5 ), and bis(1-cinnamyl-benzimidazole)silver(I) nitrate ( 6 ). Detailed synthesis and characterization of these complexes are followed by assessments of their efficacy against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli , and Candida albicans. Among the tested compounds, complex 6 exhibited the highest antimicrobial activity, with a minimal inhibitory concentration of 6 µmol/L against P. aeruginosa , and significant antibiofilm activity, achieving 67.72 % inhibition at a concentration of 3 µmol/L. These interesting findings led us to conduct a molecular docking study to understand the mechanisms of action by investigating the interactions between the silver(I) complexes and some key protein targets involved in bacterial and fungal biofilm formation, including (p)ppGpp synthetase/hydrolases, FtsZ proteins, and pyruvate kinases . This comprehensive approach, combining experimental and computational analyses derived from N -alkylbenzimidazole derivatives, particularly complex 6 , which exhibits remarkable efficacy against various pathogens, reveals promising therapeutic applications of these silver(I) complexes and advances our understanding of their potential mode of action against biofilm-associated infections.