Ruthenium (â…¡) Acyl Hydrazone Schiff Base Complexes Synthesis, Characterization And Biological Activity Research

Ruthenium complexes, launched two decades ago for antitumor therapy, are studied extensively in view of their low toxicity and good selectivity for solid tumor metastasis. Ruthenium complexes with a certain biological activity can be designed and synthesized by changing the ligands. Hydrazone compounds contain antibacterial, anti-virus and anti-tumor activites, and also because of they usually contain nitrogen, oxygen and some other donor atoms, which easily form versatile complexes with metal ions, so that their biological activites have been further extended. Therefore, we chose hydrazones as secondary ligands for the synthesis of the target complexes.The precursor complex cis-[RuCl2(DMSO)4] was synthesized by hydrated RuCl3and dimethyl sulfoxide. Seven new hydrazone ligands of pyridine-4-formaldehyde isonicotinoyl hydrazone,4-methoxybenzaldehyde isonicotinoyl hydrazone, furan-2-carboxaldehyde isonicotinoyl hydrazone,4-nitrobenzaldehyde isonicotinoyl hydrazone, acetophenone isonicotinoyl hydrazone, pyridine-4-formaldehyde benzoylhydrazone, and furan-2-carboxaldehyde benzoylhydrazone were synthesized by mixing heterocycle(aromatic) ring aldehyde(ketone) and isoniazid(or benzoyl hydrazine) in ethanol. The precursor and hydrazone ligands were characterized by elemental analysis, IR spectra and1H NMR.Seven new ruthenium(â…¡) Schiff base complexes of were synthesized by mixing precursor and hydrazone ligands in ethanol. The new complexes were characterized by elemental analysis, IR spectra, UV-Vis spectra and1H NMR. The results indicated that the replacement of one O-bonded and one S-bonded dmso ligand from the precursor by the Schiff base chelate, which acted as a neutral bidentate coordination, formed octahedral complexes of trans-[Ru(â…¡)Cl2(DMSO)2L1-7]. The electrochemical behavior of the complexes was studied with the help of cyclic voltammetry using dmso solutions of the complexes and TBAP as a supporting electrolyte.The antibacterial activity of complexes was detected by agar diffusion method. The results indicated that [Ru(â…¡)Cl2(DMSO)2L2] did not produce inhibition of the E. coli and [Ru(â…¡)Cl2(DMSO)2L5] did not produce inhibition of the aspergillus, others had a certain amount of inhibitory activity. The anticancer activity of complexes was detected by MTT method. The results show that [Ru(â…¡)Cl2(DMSO)2L4] and [Ru(â…¡)Cl2(DMSO)2L6] promote cancer cell proliferation,[Ru(II)Cl2(DMSO)2(L1,2,5,7)] show frist promote and then inhibited,[Ru(â…¡)Cl2(DMSO)2L3] as opposed to human lung cancer cell line A549in vitro proliferation inhibitory rate was negative at low concentrations, with the increasing concentration of the inhibition rate becomes positive, but the inhibition strengthis weak.