Metal Complexes of Heterocyclic Sulphonamide: Synthesis, Characterization and Biological Activity

Abstract

The metal complex of heterocyclic sulphonamide with aminopyridine is a substantial class of pharmaceutical drugs used to treat infection, diabetes, anti-inflammatory issues and neurological disorders in the field of medicinal chemistry. The research reports the synthesis, characterization and biological activity of metal complexes of heterocyclic sulphonamide of aminopyridine. Sulphonamide of heterocyclic pyridine was synthesized by reacting 2-aminopyridine and tosyl chloride in an aqueous alkaline solution at ambient temperature. The iron (II) and copper (II) complexes of the ligand were also synthesized and recrystallized with suitable solvents, and the purity levels were ascertained with melting point and thin layer chromatographic pattern. Structural elucidation of the compounds was done via Nuclear Magnetic Resonance (NMR), Ultraviolet-Visible Spectroscopy (UV-VIS) Infrared (IR), Electrospray Ionization Mass Spectrometry (ESI-MS) Micro elemental analysis. Some absorption bands in the IR spectrum of heterocyclic sulphonamide derivatives were found to shift either to higher or lower wavenumbers in the complexes, indicating the involvement of azomethine nitrogen in coordination with the metal ion. The synthesized ligand and its metal complexes were screened for antimicrobial activity against Gram (-) <i>Escherichia coli</i>, Gram (-) <i>Salmonella typhi,</i> Gram (+) <i>Staphylococcus aureus, Aspergillus flavus, Aspergillus niger and Saccharomyces cerevisiae</i>. The ligand did not show activity against the selected bacterial and fungal strains whereas; some of the coordinated ligands gave a substantial improvement on their bactericidal and fungicidal activity. The complex of copper (II) was not bioactive to all the bacteria strains but sensitive to all the fungi strains. The complex of iron (II) was susceptible to the bacteria and fungi strains, except Aspergillus flavus that was inactive. When compared to Ciprofloxacin and Ketoconazole, with a broad-spectrum antibiotic, the standard antimicrobial agents were better in sensitivity than the synthesized compound.