title: Synthesis, characterization and crystal structure of cobalt(III) complexes containing 2-acetylpyridine thiosemicarbazones: DNA/protein interaction, radical scavenging and cytotoxic activities.
abstract: The synthesis, structure and biological studies of cobalt(III) complexes supported by NNS-tridentate ligands are reported. Reactions of 2-acetylpyridine N-substituted thiosemicarbazone (HL(1-3)) with [CoCl2(PPh3)2] resulted [Co(L(1-3))2]Cl (1-3) which were characterized by elemental analysis and various spectral studies. The molecular structure of the complex 1 has been determined by single crystal X-ray diffraction studies. In vitro DNA binding studies of complexes 1-3 carried out by fluorescence studies and the results revealed the binding of complexes to DNA via intercalation. The binding constant (Kb) values of complexes 1-3 from fluorescence experiments showed that the complex 3 has greater binding propensity for DNA. The DNA cleavage activity of the complexes 1 and 3 were ascertained by gel electrophoresis assay which revealed that the complexes are good DNA cleavage agents. Further, the interactions of the complexes with bovine serum albumin (BSA) were also investigated using fluorescence spectroscopic method, which showed that the complexes 1-3 could bind strongly with BSA. The antioxidant property of the complexes was evaluated to test their free-radical scavenging ability. Furthermore, in vitro cytotoxicity of the complexes against MCF-7 and A431 cell lines was assayed which showed higher activity and efficiently vanished the cancer cells even at low concentrations.
authors.affiliation: Department of Chemistry, Periyar University, Salem 636011, Tamil Nadu, India.
authors.forename: Rajendran
authors.initials: R
authors.lastname: Manikandan
authors.affiliation: Department of Chemistry, Periyar University, Salem 636011, Tamil Nadu, India. Electronic address: viswanathamurthi72@gmail.com.
authors.forename: Periasamy
authors.initials: P
authors.lastname: Viswanathamurthi
authors.affiliation: Department of Chemistry, Karunya University, Karunya Nagar, Coimbatore 641 114, India.
authors.forename: Krishnaswamy
authors.initials: K
authors.lastname: Velmurugan
authors.affiliation: Department of Chemistry, Karunya University, Karunya Nagar, Coimbatore 641 114, India.
authors.forename: Raju
authors.initials: R
authors.lastname: Nandhakumar
authors.affiliation: Department of Materials and Life Sciences, Sophia University, Tokyo 102-8554, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Department of Materials and Life Sciences, Sophia University, Tokyo 102-8554, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Endo
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003035:Cobalt / Q000737:chemistry / Q000494:pharmacology; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D053837:DNA Cleavage; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013882:Thiosemicarbazones / Q000737:chemistry / Q000494:pharmacology; D014961:X-Ray Diffraction
chemical_list: D000970:Antineoplastic Agents; D056831:Coordination Complexes; D016166:Free Radical Scavengers; D013882:Thiosemicarbazones; D012710:Serum Albumin, Bovine; D003035:Cobalt; C033836:2-acetylpyridine thiosemicarbazone; D004247:DNA
keywords: Antioxidant activity; Cobalt(III) complexes; Cytotoxicity; DNA binding; DNA cleavage; Protein binding