Water-soluble silver(i) complexes with N-donor benzimidazole ligands containing an imidazolium core: stability and preliminary biological studies

Dalton Trans. 2021 Sep 7;50(33):11596-11603. doi: 10.1039/d1dt02008k. Epub 2021 Aug 6.

Abstract

Herein, we report the synthesis, characterisation and preliminary biological evaluation of two novel silver(i) complexes of type [AgL2](NO3)3 (3 and 4) with ionic N-donor benzimidazoles. The complexes have been synthesized by the reaction of 1.5 equivalents of silver nitrate and N-donor benzimidazoles containing an imidazolium core at the 2-position (1 and 2) in ethanol. The X-ray analysis of 4 shows that it has two free imidazolium cores and the charge is balanced with three nitrate anions. A study by the combination of NMR, IR, LC-MS and elemental analysis techniques also suggests that the complexes have this structure both in the solid-state and solution. The complexes are highly soluble and stable in water. Cytotoxicity evaluation against four cancerous human cells and one non-cancerous human cell revealed that the complexes have no significant anti-growth effect. However, the complexes showed a remarkable antimicrobial effect at normalized minimum inhibitory concentrations (normalized MICs) in the range of 33-268 μM against a panel of microorganisms consisting of Gram-negative and Gram-positive bacteria, and fungi.

MeSH terms

  • Benzimidazoles / chemistry*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry*
  • Coordination Complexes / pharmacology
  • Crystallography, X-Ray
  • Fungi / drug effects
  • Gram-Negative Bacteria / drug effects
  • Gram-Positive Bacteria / drug effects
  • Humans
  • Ligands
  • Microbial Sensitivity Tests
  • Molecular Conformation
  • Silver / chemistry*
  • Water / chemistry

Substances

  • Benzimidazoles
  • Coordination Complexes
  • Ligands
  • Water
  • Silver