A trinuclear Zn(ii) Schiff base azido compound: synthesis, structure and exploration of antimicrobial activity

Abstract

In this present work, we report the synthesis and structural characterization of a trinuclear Zn(II) complex [{ZnL(N₃)}₂Zn]·H₂O (1), which was derived from a bi-compartmental (N₂O₄) Schiff base ligand (H₂L), synthesized by the 1 : 2 condensation of 1,4-butanediamine and 3-ethoxysalicylaldehyde. The complex was characterized using elemental analysis, IR and UV-Vis spectroscopies, ¹H-NMR and single crystal X-ray diffraction studies. The antimicrobial properties of the complex have been investigated. The growing incidence of microbial resistance to available pharmaceuticals has become a major global health concern. The rationale of the study is to evaluate the antibacterial and antibiofilm activities and probable mechanism of action of the novel trinuclear zinc(II) complex. The extent of antibacterial activity was evaluated using the minimal bactericidal concentration method. The anti-biofilm potential of the compound was evaluated using the crystal violet assay and fluorescence microscopy. Radioactively labeled N-acetyl glucosamine, leucine, thymidine, and uridine were used to evaluate the effect of the zinc compound on the cell wall, protein, DNA, and RNA biosynthesis. Our zinc complex showed potential antibacterial activity against most of the tested bacterial samples with a maximum sensitivity against Pseudomonas aeruginosa. The zinc compound dependent inhibition of DNA synthesis and biofilm formation was found in Pseudomonas aeruginosa. Considering the results, we are proposing our novel zinc compound as a promising candidate for the development of antibacterial drugs.