title: Evaluation of DNA-binding, DNA cleavage, antioxidant and cytotoxic activity of mononuclear ruthenium(II) carbonyl complexes of benzaldehyde 4-phenyl-3-thiosemicarbazones.
abstract: Two 4-phenyl-3-thiosemicarbazone ligands, (E)-2-(2-chlorobenzylidene)-N-phenylhydrazinecarbothioamide (HL(1)) and (E)-2-(2-nitrobenzylidene)-N-phenylhydrazinecarbothioamide (HL(2)), and its ruthenium(II) complexes were synthesized and characterized by physico-chemical and spectroscopic methods. The Schiff bases act as bidentate, monobasic chelating ligands with S and N as the donor sites and are preferably found in the thiol form in all the complexes studied. The molecular structure of HL(1) and HL(2) were determined by single crystal X-ray diffraction method. DNA binding of the compounds was investigated by absorption spectroscopy which indicated that the compounds bind to DNA via intercalation. The oxidative cleavage of the complexes with CT-DNA inferred that the effects of cleavage are dose dependent. Antioxidant study of the ligands and complexes showed significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of the ligands and complexes assayed against HeLa and MCF-7 cell lines showed higher cytotoxic activity with the lower IC50 values indicating their efficiency in killing the cancer cells even at low concentrations.
authors.affiliation: Post-Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu, India.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Sampath
authors.forename: Subbaiyan
authors.initials: S
authors.lastname: Sathiyaraj
authors.forename: Chinnasamy
authors.initials: C
authors.lastname: Jayabalakrishnan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001547:Benzaldehydes / Q000494:pharmacology*; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D056831:Coordination Complexes / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage / Q000187:drug effects*; D004583:Electrons; D004587:Electrophoresis, Agar Gel; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D012428:Ruthenium / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013882:Thiosemicarbazones / Q000494:pharmacology*; D017186:Titrimetry
chemical_list: D000975:Antioxidants; D001547:Benzaldehydes; D056831:Coordination Complexes; D013882:Thiosemicarbazones; D012428:Ruthenium; D004247:DNA; C427203:calf thymus DNA; C032175:benzaldehyde
keywords: Antioxidant; Cytotoxicity; DNA interaction; Ruthenium(II) complexes; Thiosemicarbazones