Search results for "Cyana"
showing 10 items of 585 documents
Lovastatin protects human endothelial cells from the genotoxic and cytotoxic effects of the anticancer drugs doxorubicin and etoposide
2006
Background and purpose: 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are frequently used lipid-lowering drugs. Moreover, they exert pleiotropic effects on cellular stress responses and death. Here, we analysed whether lovastatin affects the sensitivity of primary human endothelial cells (HUVEC) to the anticancer drug doxorubicin. Experimental approach: We investigated whether pretreatment of HUVEC with low dose of lovastatin influences the cellular sensitivity to doxorubicin. To this end, cell viability, proliferation and apoptosis as well as DNA damage-triggered stress response were analysed. Key results: Lovastatin reduced the cytotoxic potency of doxorub…
Enantiomer separation by chiral-phase liquid chromatography of urethane derivatives of natural diacylglycerols previously fractionated by reversed-ph…
1991
Abstract Enantiomers of diacylglycerols such as 3,5-dinitrophenyl isocyanate (urethane) derivatives previously fractionated by reversed-phase high-performance liquid chromatography (HPLC) were separated by HPLC on a chiral phase column [N-( R )-1-(α-naphthyl)ethylamino-carbonyl-( S )-valine chemically bound to γ-aminopropylsilanized silica]. In addition to the separation of commercial monoacid-diacylglycerol isomers, separation of diacid-diacylglycerol isomers obtained from peanut oil and cottonseed oil triacylglycerols by chemical hydrolysis is reported. Hexane-ethylene dichloride-ethanol mixtures were used for elution of the diacylglycerol derivative isomers, which were detected by their …
Novel Bimetallic-Dicyanamide Extended Two- and Three-Dimensional Networks through [Cu(rac-CTH)]2+ Cation Templation
2009
Reaction of [Cu(rac-CTH)]2+ with dicyanamide and Mn2+ or Fe2+ produces three bimetallic extended structures. Complexes 1 and 2, both obtained in the same reaction pot, consist of two different (4,4) two-dimensional (2D) layers, with the [Cu(rac-CTH)(dca)]+ cations noncoordinated and coordinated to the Mn(μ1,5-dca) network for 1 and 2, respectively (rac-CTH = racemic-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). Complex 2 shows an unusual monodentate coordination mode through the central amide nitrogen of the dca ligand which is first reported for a polynuclear complex. The structure of 3 consists of a three-dimensional network which can be described as a stacking of layers m…
Reactions of Aminobis(phenolate)‐Supported Dioxidotungsten(VI) and Dioxidomolybdenum(VI) Complexes
2006
The dioxidotungsten(VI) and -molybdenum(VI) complexes [WO2(O2NOMe)] (1), [MoO2(O2NOMe)] (2) and [{MoO2(O2NMe)}2] (3) [O2NOMe methoxyethylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion, O2NMe = methylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion] can react with chloride sources (Me3SiCl, SOCl2) to form resultant monooxido dichloro compounds [WOCl2(O2NOMe)] (4), [MoOCl2(O2NOMe)] (5) and [MoOCl2(O2NMe)] (6), respectively. The reaction of tungsten complex yields of the mixture of cis-4 and trans-4, which can be separated and characterized. The reactions of analogous molybdenum complexes with Me3SiCl yield trans isomers of 5 and 6 as individual products. Reaction of dioxidot…
[Ni(cyclam)(μ1,3-dca)2Cu(μ1,5-dca)2]: A Genuine 3D Bimetallic Coordination Polymer Containing Both μ1,3- and μ1,5-Bidentate Dicyanamide Bridges and …
2005
The structure of [Ni(cyclam)(μ 1 , 3 -dca) 2 Cu(μ 1 , 5 -dca) 2 ], a genuine 3D dicyanamide-bridged bimetallic coordination polymer, is made up of 2D [Cu(μ- 1 , 5 dca) 2 ] n layers connected by [Ni(cyclam)(μ 1 , 3 -dca) 2 ] bridging moieties; it exhibits a ferromagnetic exchange interaction between copper(ll) and nickel(ll) ions through the μ 1 , 3 -bidentate dicyanamide bridges.
Anion-Directed Self-Assembly of Unusual Discrete and One-Dimensional Copper(II) Complexes of 3,6-Bis(2′-pyridyl)pyridazine
2012
The preparation and crystal structures of six new copper(II) compounds of formula [Cu(dppn)2(ClO4)]ClO4 (1), [Cu2(dppn)(OH)(ClO4)3(H2O)3]·H2O (2), [Cu2(dppn)2(H2O)2](ClO4)4 (3), [Cu2(dppn)2(ClO4)4] (4), {[Cu2(dppn)(N3)4]·H2O/[Cu2(dppn)(N3)4(H2O)]}n (5) and {[Cu2(dppn)(OH)(dca)3]·H2O}n (6) [dppn = 3,6-bis(2′-pyridyl)pyridazine and dca = dicyanamide] are reported. 1 is a mononuclear complex where two bidentate dppn molecules and a monodentate perchlorate build an intermediate square pyramidal/trigonal bipyramidal (sp/tbp) five-coordinate environment around the copper(II) ion, the overall positive charge being balanced by a free perchlorate anion. 2–4 are dinuclear complexes with either one (2…
Three one-dimensional systems with end-to-end dicyanamide bridges between copper(ii) centres: structural and magnetic properties
2002
The preparation, crystal structures and magnetic properties of three different copper(II) chains of formula [Cu(pyim)(H2O)(dca)]n(NO3)n (1), [Cu(dpa)(dca)2]n (2) and [Cu(bpa)(dca)2]n (3) [pyim = 2-(2-pyridyl)imidazole, dca = dicyanamide anion, dpa = 2,2′-dipyridylamine and bpa = 1,2-bis(4-pyridyl)ethane] are reported. A chain structure with single, symmetrical, end-to-end dca bridges is found in compound 1. This bridging mode, with two short, equatorially coordinated Cu–N bonds has not been previously observed in the [Cu(dca)Xn] (X = coligand) family of compounds. The copper atom in 1 has a distorted square pyramidal geometry with a bidentate pyim ligand and two nitrile nitrogen atoms from …
Syntheses, crystal structures and magnetic properties of copper(ii) dicyanamide complexes; dinuclear, chain and ladder compounds
2002
The preparation, crystal structures and magnetic properties of three heteroleptic copper(II) complexes with dicyanamide (dca) bridges, [Cu(bpca)(H2O)(dca)]2 (1) (bpca = bis(2-pyridylcarbonyl)amidate), [Cu(bpy)(dca)2]n (2) (bpy = 2,2′-bipyridine), [Cu2(bpm)(dca)4]n (3) (bpm = 2,2′-bipyrimidine) are reported. In addition, magnetic susceptibility measurements of the sheetlike polymer [Cu(phen)(dca)2] (4) (phen = 1,10-phenanthroline), structurally characterized previously, have been performed. In complex 1 pairs of mononuclear structural building blocks, [Cu(bpca)(dca)(H2O)], are loosely connected through a 1,3-dca bridge in which nitrile is equatorially bound and the amide is semi-coordinated …
Preparation, crystal structure and magnetic properties of di-2-pyridylamine (dpa) copper(II) complexes [Cu(dpa)(N3)2]n and [Cu2(dpa)2(NCO)4]
2008
Abstract The preparation, crystal structures and magnetic properties of two copper(II) complexes with di-2-pyridylamine (dpa) as end-cap ligand and azide (1) and cyanate (2) as bridging groups, [Cu(dpa)(N3)2]n (1) and [Cu2(dpa)2(NCO)4] (2), are reported. Compound 1 consists of uniform chains of copper(II) ions bridged by single μ-1,1-azido groups whereas that of compound 2 is made up of centrosymmetric dicopper(II) units with double μ-1,1-N-cyanate bridges, the other two cyanate groups acting as terminal ligands. The copper atoms in 1 and 2 are five-coordinated with two nitrogen atoms of a bidentate dpa ligand (1 and 2), one nitrogen atom from a terminally bound azide (1)/cyanate (2) and tw…
2,2′-Bipyrimidine- and 2,3-bis(2-pyridyl)pyrazine-containing manganese(II) compounds: Structural and magnetic properties
2003
The preparation, crystal structures and magnetic properties of four different manganese(II) compounds of formula [Mn(bipym)Cl2]n·2nH2O (1), [Mn2(dpp)2(H2O)2Cl4]·2H2O (2), [Mn(dpp)(H2O)2]n(ClO4)2n·1.5nH2O (3) and [Mn(dpp)(dca)2]n (4) [bipym = 2,2′-bipyrimidine, dpp = 2,3-bis(2-pyridyl)pyrazine and dca = dicyanamide anion] are reported. Compounds 1 and 3 are uniform chains of six-coordinated manganese(II) ions bridged by bis(bidentate) bipym (1) and dpp (3) ligands with two chloride groups (1) and two water molecules (3) in cis position. The electroneutrality in 3 is achieved by uncoordinated perchlorate anions. The manganese atom in 1 and 3 exhibits a distorted octahedral environment mainly …