Palladium (II) complexes containing substituted thiosemicarbazones. Synthesis, spectral characterization, X-ray crystallography, biomolecular interactions and in vitro cytotoxicity

Palladium (II) complexes were synthesized from 4(N)-substituted thosemicarbazones schiff base ligands. The new complexes were confirmed by analytical, various spectroscopic techniques and single crystal X-ray crystallography. Crystallographic studies exhibited that the complexes 2 and 3 distorted square planar geometry around palladium metal ion. All the complexes are proved their DNA/protein binding ability by using absorption and emission titrations. Investigations of antioxidant properties showed that all the complexes have significant radical scavenging properties. The anticancer activity of Pd(II) complexes was probed in vitro cytotoxicity against human breast (MCF7) and lung (A549) cancer cell lines by MTT assay. Further, AO/EB and DAPI staining methods were carried out to detect the cell death induced by the complexes. Among all the complexes, complex 1 exhibited better cytotoxic activity. [Display omitted] •Four new Pd(II) complexes have been synthesized.•The structure of the complexes 2 and 3 were confirmed by X-ray crystallography.•The DNA/protein binding studies were carried with CT-DNA and BSA as models.•Complexes exhibited significant free radical scavenging activities.•The anticancer activity of the Pd(II) complexes was probed in vitro cytotoxicity against human breast (MCF7) and lung (A549) cancer cell lines by MTT assay and cytological changes observed in (AO/EB and DAPI) staining method.