Biological evaluation, DNA/protein-binding aptitude of novel dibenzosuberene appended palladium (II)-thiourea complexes

Four novel Pd (II)-thiourea square-planar derivatives of the type [PdCl2L2] (L = N-dibenzosuberenyl appended aroyl/acylthiourea ligand) (1-4) were synthesized and well characterized. The neutral monodentate S coordination of ligand with palladium (II) ion was confirmed by single crystal X-ray diffraction method. In vitro calf thymus DNA (CT-DNA) interaction studies were investigated, and the results of the complexes showed the intercalative mode of binding (in the order of 1 > 3 > 2 > 4) with complexes. The binding affinity of the compounds with bovine serum albumin (BSA) was studied, and it was found that the binding affinity of the complexes with DNA and BSA was different. In addition, the antimicrobial activity evaluation results revealed that compound 2 has registered excellent antibacterial activity against four strains, and also compounds 2 and 4 have shown good antifungal activity against the microorganisms compared with their reference drugs. The scavenging activity of compound 3 showed potent activity with an IC50 value of 6.95 +/- 1.81 mu M. Furthermore, the in vitro anti-proliferative activity results clearly suggested that complex 3 showed most potent cytotoxic activity against human neuroblastoma (IMR-32) cell line, with an IC50 value of 15.21 +/- 0.359 mu M compared with the reference drug.