In vitro antimicrobial evaluation, effects of halide concentration and hemolysis study of silver-N-heterocyclic carbene complexes

The morpholine containing silver complexes were screened for the zone of inhibition, MIC determination, and longevity studies against bacterial growth. The most potent compounds SC-4 (Silver Complex-4) and SC-5 inhibited the bacterial growth with MIC of 12.5 and 6.25 µM against Staphylococcus aureus, respectively, and 50 µM against Salmonella enterica with an efficient growth inhibition up to 21 days with disruption of cell wall as monitored by SEM analysis. The side chain was varied to evaluate the possible changes in antimicrobial effects. The Ag–NHCs SC-4 and SC-5 had shown enhanced bactericidal effects due to the synergistic effects of NaCl and Ag–NHCs when studied at 12.5 µM along with 10 g/L NaCl. The complex SC-5 induced considerable RBC (red blood corpuscles) rupture at 50 µM compared to IS-5 (imidazolium salt) and directly proportional to concentration.