Synthesis, spectral characterization, DNA interaction, radical scavenging and cytotoxicity studies of ruthenium(II) hydrazone complexes

• An octahedral geometry has been assigned for all the complexes based on spectroscopic evidences.
• The complexes bind with CT-DNA via intercalation and the efficiency is higher for complexes than the ligands.
• All the complexes cleave the CT-DNA. In particular, complex 6 possesses effective cleavage activity.
• The complexes arrest the formation of NO radicals more efficiently.
• The complex 6 shows higher IC50 value than the other complexes against cancer cells.

Three new ruthenium(II) complexes with hydrazone ligands, furan-2-carboxylic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL1), furan-2-carboxylic acid [4-(ethyl-propyl-amino)-2-hydroxy-benzylidene]-hydrazide (HL2) and furan-2-carboxylic acid (3-ethoxy-2-hydroxy-benzylidene)-hydrazide (HL3) were synthesized and characterized by various spectro-analytical techniques. The hydrazone ligands act as a tridendate ligand with ONO as the donor sites and are preferably found in the enol form in all the complexes. The molecular structure of the ligands was determined by single crystal X-ray diffraction technique. The interaction of the ligands and the complexes with CT-DNA were evaluated by an absorption titration method which revealed that the compounds interact with CT-DNA through intercalation. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the calf thymus DNA hydrolytically. Antioxidant studies showed that the ruthenium(II) complexes have a strong radical-scavenging properties. Further, the cytotoxic effect of the compounds examined on cancerous cell lines showed that the complexes exhibited substantial anticancer activity.

Three new ruthenium(II) hydrazone complexes were synthesized from the reactions of furan-2-carboxylic acid hydrazide with salicylaldehyde derivatives. Structural features of the ligands and complexes have been characterized by various spectro-analytical techniques. The molecular structures of the hydrazone ligands were determined by single crystal X-ray diffraction technique. The binding behavior of free ligand and complexes with CT-DNA were investigated by absorption spectroscopy. The results suggest that compounds bind with CT-DNA via intercalation mode. A gel electrophoresis assay demonstrated the ability of the complexes to cleave the calf thymus DNA. Further, in vitro antioxidant and anticancer studies were carried out for the ruthenium(II) hydrazone complexes.Figure optionsDownload as PowerPoint slide