Solution studies, synthesis and antibacterial activity of Ga(III) complexes with bis-kojate derivatives

J Inorg Biochem. 2024 Oct:259:112663. doi: 10.1016/j.jinorgbio.2024.112663. Epub 2024 Jul 14.

Abstract

Given the recognized major problem of microbial drug resistance for human health, new metal-based drugs have been currently explored for their antimicrobial properties, including gallium-based compounds as potential metallophores that could perturb Fe's interactions with proteins. Herein we have designed and synthesized two bis-kojate ligands (named L4 and L6) and studied their Ga(III) complexes for their physico-chemical and biological properties. In particular a detailed study of their complexation properties in aqueous solution, showed equilibrium models with formation of quite stable dinuclear 2:3 metal:ligand complexes, though with different stability. Solid state complexes were also prepared and characterized and complementary DFT studies indicated that [Ga2(L4)3] complex, with higher stability, seems to adopt a three-ligand bridging conformation, while that for L6 adopt a one ligand bridging conformation. Preliminary investigation of the antibacterial activity of these gallium complexes showed antipseudomonal activity, which appeared higher for the complex with L4, a feature of potential interest for the scientific community.

Keywords: Antibacterial; Bis-kojic acid; Gallium; Hydroxypyrones; Metallophores; P. aeruginosa.

MeSH terms

  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Coordination Complexes* / chemical synthesis
  • Coordination Complexes* / chemistry
  • Coordination Complexes* / pharmacology
  • Gallium* / chemistry
  • Gallium* / pharmacology
  • Ligands
  • Microbial Sensitivity Tests*

Substances

  • Gallium
  • Anti-Bacterial Agents
  • Coordination Complexes
  • Ligands