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Two novel Cd(II) and Zn(II) complexes with the condensation product of 2-formylpyridine and selenosemicarbazide were synthesized. The structure of Cd(II) complex was determined by X-ray crystallography. The ligand is coordinated in a neutral form via pyridine and azomethine nitrogen atoms and the selenium donor. The cadmium ion completes its five-coordination by two chloride ligands, forming a square-pyramidal geometry. The structure of Zn(II) complex was established by analysis of spectroscopic data, which indicated coordination of the ligand as a bidentate via the selenium and the azomethine nitrogen atoms. The cytotoxic activity of the newly synthesized complexes, as well as if five structurally related complexes and the ligand evaluated against eight tumor cell lines. The new Cd(II) complex showed the highest activity similar to cisplatin with IC50 less than 10muM for all cell lines. Cell cycle distribution and apoptosis study showed that Cd(II) complex and cisplatin might have some similarity in anticancer activity, which was not the case for cisplatin and other studied complexes. Effects of the complexes on matrix metalloproteinases (MMPs) MMP-9 and MMP-2 was also studied. Cd(II) and Zn(II) complexes and cisplatin increased MMP-2 activity in supernatants of tested cells, while Ni(II) complex with the same ligand decreased the activity, implying a possible activity in preventing tumor invasion and metastasis processes.

The synthesis and chemical characterization of the novel 2,6-diacetylpyridine-bis(selenosemicarbazone) metal complexes of Zn(II), Cd(II) and Ni(II) were published previously. Here we report first evidence on anti-proliferative activity of the complexes and molecular patterns that underlie it. The complexes and the corresponding ligand are shown to be cytotoxic on the panel of nine, malignant and non-malignant cell lines, with the exception of Ni(II) complex that did not achieve IC50 value on any of the cell lines tested. Further experiments on the selected cell lines including A 549, MRC-5, EA.hy 926 and HeLa, have shown that the complexes posses unambiguous property of inducing necrosis in the cells treated for 6 hours, with the ligand and Zn(II) complex being the most active on all cell lines. On the contrary, only small portion of early apoptotic events was detected, under the same experimental condition. This was in complete concordance with the results obtained from Western blot analysis of the treated cells that showed no or slight increase of the protein amounts of two crucial apoptotic mediators: Cytochrome C and Caspase III. We propose the model, under which tested complexes induce necroptosis in treated cells, a recently described type of cell death with necrotic morphological features and acting via caspase independent pathway, and without elevated amounts of intracellular ROS. Endothelial EA.hy 926 cells have proven to be extremely sensitive on the necrosis-inducing effect of the complexes, which could indicate potential anti-angiogenic effect of the novel complexes that is to be investigated.

The title salt, C(16)H(18)N(6)O(2)(2+)center dot 2ClO(4)(-)center dot 2H(2)O, was obtained unintentionally as a major product in the reaction of Zn(ClO(4))(2)center dot 6H(2)O with the N',N'(2)-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (H(2)L) ligand. The (H(4)L)(2+) cation lies across a centre of inversion. The pyridiniumimine fragments of (H(4)L)(2+) adopt syn orientations. Intramolecular N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds lead to the formation of S(5) motifs. In the crystal, neighbouring cations are connected by pi-pi interactions between pyridinium units with a centroid-centroid distance of 3.600 (1) angstrom. Moreover, the crystal components are assembled into two-dimensional layers via N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds, with no direct hydrogen-bonding interactions between cations.

New complexes of Pt(II) and Pd(II) with 2-quinolinecarboxaldehyde selenosemicarbazone were synthesized and characterized by elemental analysis, NMR and IR spectroscopy and molar conductivity measurements. The assumed geometry of Pt(II) and Pd(II) complexes was square planar where the ligand was tridentately coordinated via the quinoline and imine nitrogen atoms and the selenium atom. The cytotoxic activity of the new Pt(II) and Pd(II) compounds, as well as of some previously synthesized Cd(II), Zn(II) and Ni(II) complexes with the same or analogous ligand, was tested against a panel of three human cancer cell lines: human cervix carcinoma cells (HeLa), human melanoma cells (FemX) and breast cancer cells (MDA-361). All investigated compounds, except Pt(II) complex, possess a strong dose-dependent cytotoxic activity of the same order of magnitude as cisplatin (CDDP). The investigation of potential of these compounds to induce HeLa cell cycle perturbations was also evaluated. (c) 2008 Elsevier Masson SAS. All rights reserved.

The structure of the title compound, [Ca(C(10)H(15)O(4)S)(2)(H(2)O)(4)], is the first example in which two D-camphor-10-sulfonate anions are coordinated to a metal ion, in this case with direct Ca-O bonding. The molecule has crystallographically imposed twofold symmetry with the Ca atom on the twofold axis. Hydrogen bonds are formed between the coordinated water molecules and the O atoms of the SO(3)(-) groups of adjacent molecules, leading to the formation of a two-dimensional layered network. The compound displays sharp wavelength-selective transparency in the UV-visible spectrum, offering the potential for application as an optical filter.

The structure of the title complex, [Mg(H2O)(6)](C10H15O4S)(2), consists of regular octahedral [Mg(H2O)(6)](2+) cations and D-camphor-10-sulfonate anions. A three-dimensional supra-molecular architecture is formed via hydrogen-bond interactions [O-H center dot center dot center dot O = 2.723 (2)-2.833 (2) angstrom] to give alternating layers of [Mg(H2O)(6)](2+) cations and D-camphor-10-sulfonate anions. The title compound is isomorphous with the zinc, copper, cadmium and nickel analogues.

The complexes of Cu(II) and condensation products of usnic acid with the acyl hydrazides of α-naphthoic, caprylic and oxamic acid, as well as the derivative of usnic acid with thiosemicarbazide have been synthesized and characterized by elemental analyses, molar conductivity, magnetic moment measurements and IR spectroscopy. It was found that the derivatives act as tridentates occupying three coordination places in the square planar molecules with the fouith coordination site occupied by a solvent molecule. The complexes were tested for in vitro growth inhibitory activity against the bacterial species Escherichia coli and Slaphylococcus aureus. The complexes have higher antibacterial activities compared to both the usnic acid derivatives and Cu(II) ions.