title: Two new Co(II) and Ni(II) complexes with 3-(2-Pyridyl)pyrazole-based ligand: synthesis, crystal structures, and bioactivities.
abstract: Two new Co(II) and Ni(II) complexes exhibiting DNA cytotoxic activities with 3-(2-pyridyl)pyrazole-based ligand, [Co(L)(3)](ClO(4))(2) (1) and [Ni(L)(3)](ClO(4))(2) (2) (L=1-[3-(2-pyridyl)-pyrazol-1-ylmethyl]-naphthalene) were synthesized and structurally characterized. Both 1 and 2 crystallized in the monoclinic system, space group P2(1)/c, for 1, a=12.8324(8), b=12.1205(8), c=33.27(2) A, beta=93.92(3) degrees and Z=4; for 2, a=12.8764(3), b=12.1015(3), c=33.2415(9) A, beta=93.998(1) degrees and Z=4. Among them, the Co(II) and Ni(II) ions were all coordinated by six N donors from three distinct L ligands. In addition, the cytotoxic activities of 1, 2 and L in vitro were evaluated against three different cancer cell lines HL-60 (human leukemia), BGC-823 (stomach cancer) and MDA-MB-435 (mammary cancer), respectively. The results showed that 1 exhibited significantly high cytotoxic activities against HL-60 and moderate activities against BGC-823 and MDA-MB-435. In order to further investigate the relationships between structures and DNA-binding behaviors of these complexes, the interactions of 1, 2 and L with calf thymus DNA (CT-DNA) were then subjected to thermal denaturation, viscosity measurements and spectrophotometric methods. The results indicated that 1 and 2 intercalated with DNA via L ligand. The intrinsic binding constants of 1, 2 and L with DNA were 1.6x10(4), 5.6x10(3) and 2.76x10(3) M(-1), respectively.
authors.affiliation: Department of Chemistry, Nankai University, Tianjin, PR, China.
authors.forename: Chun-Sen
authors.initials: CS
authors.lastname: Liu
authors.forename: Hang
authors.initials: H
authors.lastname: Zhang
authors.forename: Ran
authors.initials: R
authors.lastname: Chen
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Shi
authors.forename: Xian-He
authors.initials: XH
authors.lastname: Bu
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D011720:Pyrazoles / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D008024:Ligands; D009942:Organometallic Compounds; D011720:Pyrazoles; D011725:Pyridines; D003035:Cobalt; D009532:Nickel; D004247:DNA