Tatiyana V. Serebryanskaya

Synthesis, characterization, and biological evaluation of new tetrazole-based platinum(II) and palladium(II) chlorido complexes--potent cisplatin analogues and their trans isomers.

Two series of tetrazole-containing platinum(II) and palladium(II) chlorido complexes, trans-[ML(2)Cl(2)] (M=Pt, Pd) and cis-[PtL(2)Cl(2)]·nH(2)O (n=0, 1), where L is 1- or 2-substituted 5-aminotetrazole, have been synthesized and thoroughly characterized. Configuration of platinum(II) complexes obtained from the reaction of 5-aminotetrazoles with K(2)PtCl(4) has been found to vary depending on the nature of tetrazole derivatives and reaction conditions. According to in vitro cytotoxic evaluation, only platinum complexes display noticeable antiproliferative effect, and their cytotoxicity depends strongly on their geometry and hydrophobicity of the carrier ligands. The most promising complexes are cis-[Pt(1-apt)(2)Cl(2)]·H(2)O and cis-[Pt(2-abt)(2)Cl(2)]·H(2)O, where 1-apt is 5-amino-1-phenyltetrazole and 2-abt is 5-amino-2-tert-butyltetrazole. In comparison with cisplatin, they show comparable cytotoxic potency against cisplatin-sensitive human cancer cell lines, cis-[Pt(2-abt)(2)Cl(2)]·H(2)O performing substantially higher activity against cisplatin-resistant cell lines. Cell cycle studies in H1299 cell line indicated that cis-[Pt(2-abt)(2)Cl(2)]·H(2)O induced apoptosis launched from G2 accumulations. The DNA interaction with cis-[Pt(1-apt)(2)Cl(2)]·H(2)O was followed by UV spectroscopy, circular dichroism, hydrodynamic and electrophoretic mobility studies. Both cis-[Pt(1-apt)(2)Cl(2)]·H(2)O and cis-[Pt(2-abt)(2)Cl(2)]·H(2)O complexes appeared to be significantly less toxic than cisplatin in mice, while only compound cis-[Pt(1-apt)(2)Cl(2)]·H(2)O displayed noticeable efficacy in vivo.

A novel aminotriazole-based NHC complex for the design of gold(I) anti-cancer agents: synthesis and biological evaluation

A novel gold(I) complex based on an aminotriazole N-heterocylic carbene ligand represents a promising scaffold for the design of anticancer bioorganometallics. The complex triggered cytotoxic effects in HT-29 and MDA-MB-231 cancer cells, inhibited the activity of the enzyme thioredoxin reductase and showed an effective and fast cellular accumulation.

catena-Poly[[bis­[1-(2-hydroxy­ethyl)-1H-tetra­zole-κN4]copper(II)]-di-μ-chlorido]: a powder study

The crystal structure of the title polymeric complex, [CuCl2(C3H6N4O)2]n, was obtained by the Rietveld refinement from laboratory X-ray powder diffraction data collected at room temperature. The unique CuII ion lies on an inversion center and is in a slightly distorted octahedral coordination environment. In the hydroxyethyl group, all H atoms, the O atom and its attached C atom are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4. The OH group is involved in an intramolecular O—H⋯N hydrogen bond.

An X-ray powder study of the structure and microstructure of trans-dichloridobis(1,5-diamino-1H-tetrazole-κN4)palladium(II)

Abstract The crystal structure of the coordination compound [PdCl2(CH4N6)2], trans-dichloridobis(1,5-diamino-1H-tetrazole-κN4)palladium(II), has been determined from X-ray powder diffraction data collected at room temperature. The structure has been solved by direct methods and refined using Rietveld analysis. The complex crystallizes in the monoclinic space group P21/c, with Z=2. The unit cell dimensions are a=5.73491(4), b=11.94450(4), c=8.61685(4)Å, and β=99.6367(6)° with cell volume V=581.930(5)Å3. A slightly distorted square-planar coordination geometry is formed around the Pd atom by two Cl atoms and two tetrazole ring N atoms of two 1,5-diamino-1H-tetrazole ligands, which are in a trans configuration. In the complex molecule, the planes of the tetrazole rings are inclined at 53.7(3)° with respect to the coordination plane. Intermolecular hydrogen bonds of the amino groups N—H···Cl and N—H···Nring are responsible for formation of a three-dimensional supramolecular network. The powder pattern of the compound was strongly affected by the anisotropic line broadening. The width of the Bragg peaks was interpreted by a phenomenological microstructural approach in terms of anisotropic strain effect to complete the Rietveld refinement.

Palladium(II)-Stabilized Pyridine-2-Diazotates: Synthesis, Structural Characterization, and Cytotoxicity Studies

Well-defined diazotates are scarce. Here we report the synthesis of unprecedented homoleptic palladium(II) diazotate complexes. The palladium(II)-mediated nitrosylation of 2-aminopyridines with NaNO2 results in the formation of metal-stabilized diazotates, which were found to be cytotoxic to human ovarian cancer cells.