An investigation on the DNA/protein binding, DNA cleavage and in vitro anticancer properties of SNO pincer type palladium(II) complexes with N-substituted isatin thiosemicarbazone ligands

摘要

Graphical abstract SNO pincer type palladium(II) complexes with N-substituted isatin thiosemicarbazone ligands have been synthesized and evaluated for its biological applications like DNA/protein binding, DNA cleavage and cytotoxicity studies. Display Omitted Highlights ? Three new palladium(II) complexes were synthesized and structurally characterized. ? The DNA/protein-binding properties was investigated. ? Complexes show significant activity against A549 & MCF7 cancer cell lines. ? Three complexes interacted with DNA/BSA with appreciable binding constant. ? The DNA cleavage study showed the complexes cleaved DNA without any external agents. Abstract Three pincer type palladium(II) complexes (1–3) were synthesised from the reactions of PdCl2 with thiosemicarbazone ligands (L1–L3), and characterized by elemental analyses and UV Visible, FT-IR, 1H &13C NMR spectroscopic techniques. The molecular structure of 2 was confirmed by single crystal X-ray crystallography. The X-ray diffraction study of complex 2 revealed the pincer type tridentate SNO coordination of N-substituted isatin thiosemicarnbazone with the palladium ion. The binding affinity and mode of the palladium(II) complexes (1–3) toward calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were determined by UV–Visible and fluorescence spectrophotometric methods. Spectral evidences showed intercalative mode of DNA binding with the palladium(II) complexes. The magnitude of hypochromism is in the order of 3 2