Green synthesis, structural elucidation, antimicrobial, and cytotoxic activities of a Schiff base and its Pd(II) complexes

This paper includes the synthesis of a Schiff base ligand and its palladium(II) complexes by conventional and green microwave-assisted techniques. They were characterized by conductivity measurements, mass spectrometry, FTIR, electronic spectroscopy, H-1 NMR, and X-ray powder diffraction techniques. Based on analytical and spectral data, a square planar geometry was proposed for the metal complexes. The ligand(LH) and its metal complex[Pd(L)(2)] were screened for antimicrobial activity against pathogenic bacterial(Escherichia coli, Staphylococcus aureus) and fungal(Aspergillus niger, Penicillium chrysogenum) strains. Ciprofloxacin and Ketoconazole were used as standard drugs for antibacterial and antifungal activities respectively. The compounds showed moderate activity. The starting material(PdCl2), ligand(LH), and the metal complex [Pd(L)(2)] were screened for in vitro cytotoxic activity by MTT assay against cancerous cell lines (HeLa, MCF-7). Cisplatin was used as the standard drug. The metal complex, [Pd(L)(2)] was also screened for cytotoxic activity against normal cell line(HEK 293) to determine the selectivity index. The values of S.I(3.70-4.58) indicated that the complex [Pd(L)(2)] was more sensitive towards cancerous cell lines than normal cell line and may be studied further to assess its potential as cytotoxic agent.