title: Effect of substitution and planarity of the ligand on DNA/BSA interaction, free radical scavenging and cytotoxicity of diamagnetic Ni(II) complexes: a systematic investigation.
abstract: Four new bivalent nickel hydrazone complexes have been synthesised from the reactions of [NiCl(2)(PPh(3))(2)] with H(2)L {L = dianion of the hydrazones derived from the condensation of salicylaldehyde or o-hydroxy acetophenone with p-toluic acid hydrazide (H(2)L(1)) (1), (H(2)L(2)) (2) and o-hydroxy acetophenone or o-hydroxy naphthaldehyde with benzhydrazide (H(2)L(3)) (3) and (H(2)L(4)) (4)} and formulated as [Ni(L(1))(PPh(3))] (5), [Ni(L(2))(PPh(3))] (6), [Ni(L(3))(PPh(3))] (7) and [Ni(L(4))(PPh(3))] (8). Structural characterization of complexes 5-8 were accomplished by using various physico-chemical techniques. In order to study the influence of substitution in the ligand and its planarity on the biological activity of complexes 5-8 containing them, suitable hydrazone ligands 1-4 have been selected in this study. Single crystal diffraction data of complexes 5, 7 and 8 proved the geometry of the complexes to be distorted square planar with a 1 : 1 ratio between the metal ion and the coordinated hydrazones. To provide more insight on the mode of action of complexes 5-8 under biological conditions, additional experiments involving their interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) were monitored by UV-visible and fluorescence titrations respectively. Further, the ligands 1-4 and corresponding nickel(ii) chelates 5-8 have been tested for their scavenging effect towards OH and O(2)(-) radicals. The effect of complexes 5-8 to arrest the growth of HeLa and Hep-2 tumour cell lines has been studied along with the cell viability against the non-cancerous NIH 3T3 cells under in vitro conditions.
authors.affiliation: Department of Chemistry, Bharathiar University, Coimbatore, India.
authors.forename: Palanisamy
authors.initials: P
authors.lastname: Sathyadevi
authors.forename: Paramasivam
authors.initials: P
authors.lastname: Krishnamoorthy
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Butorac
authors.forename: Alan H
authors.initials: AH
authors.lastname: Cowley
authors.forename: Nattamai S P
authors.initials: NS
authors.lastname: Bhuvanesh
authors.forename: Nallasamy
authors.initials: N
authors.lastname: Dharmaraj
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D002417:Cattle; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D016166:Free Radical Scavengers / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D008280:Magnetics; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D016166:Free Radical Scavengers; D008024:Ligands; D009942:Organometallic Compounds; D012710:Serum Albumin, Bovine; D009532:Nickel; D004247:DNA; C427203:calf thymus DNA