613 research outputs found

    A novel oxidovanadium(V) compound with an isonicotinohydrazide ligand: A combined experimental and theoretical study and cytotoxity against K562 cells

    Get PDF
    The interaction of oxidovanadium(V) with INHOVA (the condensation product of isoniazid and o-vanillin) lead to the formation of the ester-like complex [VO(INHOVA)EtO(OH2)]Cl·H2O (1). Crystals suitable for X-ray diffraction methods were obtained. The complex crystallizes as a dimer in the space group P21/c of the monoclinic system. A detailed analysis, including solid-state vibrational spectroscopy and electronic spectroscopy in DMSO solution, was performed for both INHOVA and complex (1). A complete theoretical study based on DFT was also carried out. The calculations were of valuable assistance in the spectra assignments and interpretation. The electrochemical characterization allows determining the redox behavior of INHOVA and complex (1). Cytotoxicity was assayed against the chronic myelogenous leukemia K562 cell line. The IC50 values obtained denote that both the ligand and complex (1) are good candidates for further studies.Fil: Gonzalez Baro, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Ferraresi Curotto, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Pis Diez, Reinaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Parajón Costa, Beatriz Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Resende, Jackson A. L. C.. Cua/ufmt; . Universidade Federal do Mato Grosso do Sul; BrasilFil: de Paula, Flávia C. S.. Universidade Federal de Minas Gerais; BrasilFil: Pereira Maia, Elene C.. Universidade Federal de Minas Gerais; BrasilFil: Rey, Nicolás A.. Universidade de Sao Paulo; Brasi

    A novel oxidovanadium(V) compound with an isonicotinohydrazide ligand: A combined experimental and theoretical study and cytotoxity against K562 cells

    Get PDF
    The interaction of oxidovanadium(V) with INHOVA (the condensation product of isoniazid and o-vanillin) lead to the formation of the ester-like complex [VO(INHOVA)EtO(OH2)]Cl·H2O (1). Crystals suitable for X-ray diffraction methods were obtained. The complex crystallizes as a dimer in the space group P21/c of the monoclinic system. A detailed analysis, including solid-state vibrational spectroscopy and electronic spectroscopy in DMSO solution, was performed for both INHOVA and complex (1). A complete theoretical study based on DFT was also carried out. The calculations were of valuable assistance in the spectra assignments and interpretation. The electrochemical characterization allows determining the redox behavior of INHOVA and complex (1). Cytotoxicity was assayed against the chronic myelogenous leukemia K562 cell line. The IC50 values obtained denote that both the ligand and complex (1) are good candidates for further studies.Centro de Química Inorgánic

    1,2-Dihydr­oxy-2-(3-methyl­but-2-en­yl)-3-oxo-2,3-dihydro-1H-indene-1-carboxylic acid monohydrate

    Get PDF
    The title compound, C15H16O5·H2O, is an inter­mediate of the Hooker oxidation reaction, used for the synthesis of 2-hydr­oxy-3-(2-methyl­prop-1-en­yl)naphthalene-1,4-dione (nor-lapachol). The packing in the crystal structure is arranged by an O—H⋯O hydrogen-bonded network along the [100] and [010] directions. Each organic mol­ecule is linked to four other mol­ecules via the hydr­oxy groups. The water solvent mol­ecule is connected to carboxylic acid groups by three hydrogen bonds

    Synthesis, characterization and catalytic activity of two novel cis-dioxovanadium(v) complexes: [VO2(L)] and [VO2(Hlox)]

    Full text link
    Two novel complexes, [VO2(L)] (1) and [VO2(HLox)] (2), were synthesized and characterized by IV, UV-Vis and NMR spectroscopy, cyclic voltammetry, elemental analysis and X-ray diffraction. The synthesis of a new ligand, H2Lox, is also described. Complexes 1 and 2 were obtained by the reaction of [VO(acac)2] with the ligands HL and H2Lox, respectively. Alternatively, 2 was also obtained by the reaction of HL with [VO(acac)2] in the presence of hydroxylamine, and by the reaction of 1 with hydroxylamine. Crystallographic data show that complexes 1 and 2 have similar molecular structures, in which the cis-dioxovanadium(V) center is coordinated to L- or HLox-, respectively, in a distorted octahedral environment. The catalytic activity of these compounds towards cyclohexane oxidation was evaluated using H2O2 and t-BuOOH as oxidants. Both complexes presented > 70% selectivity for cyclohexylhydroperoxide formation. B3LYP/6-31G(d) calculations were used to confirm the geometry and to help assign the electronic spectra

    A stereoselective, base-free, palladium-catalyzed heck coupling between 3-halo-1,4-naphthoquinones and vinyl-1H-1,2,3-triazoles

    Get PDF
    A stereoselective, base-free Heck coupling between 1,4-naphthoquinone and 1H-1,2,3-triazole derivatives was reported for the first time. This study shows that depending on the 1,4-naphthoquinone, the use of an additional base is unnecessary to produce the naphthoquinone-triazole conjugates. This is also the first example of a Heck coupling of these two cores without using a base as an additive. In this work, sixteen new naphthoquinone-triazole hybrids were stereoselectively synthetized in good to excellent yields. The reaction mechanism was discussed based on DFT CAM−B3LYP calculations. The first step is the coordination of the arene to the palladium catalyst to form a palladacycle intermediate. After reorganization in this intermediate, the double bond in the arene is restored to proceed with the coupling step and formation of the C−C bond in the rate determining step. The Kozuchi-Shaik span model was employed to rationalize substituent effects

    Network model of immune responses reveals key effectors to single and co-infection dynamics by a respiratory bacterium and a gastrointestinal helminth

    Get PDF
    Co-infections alter the host immune response but how the systemic and local processes at the site of infection interact is still unclear. The majority of studies on co-infections concentrate on one of the infecting species, an immune function or group of cells and often focus on the initial phase of the infection. Here, we used a combination of experiments and mathematical modelling to investigate the network of immune responses against single and co-infections with the respiratory bacterium Bordetella bronchiseptica and the gastrointestinal helminth Trichostrongylus retortaeformis. Our goal was to identify representative mediators and functions that could capture the essence of the host immune response as a whole, and to assess how their relative contribution dynamically changed over time and between single and co-infected individuals. Network-based discrete dynamic models of single infections were built using current knowledge of bacterial and helminth immunology; the two single infection models were combined into a co-infection model that was then verified by our empirical findings. Simulations showed that a T helper cell mediated antibody and neutrophil response led to phagocytosis and clearance of B. bronchiseptica from the lungs. This was consistent in single and co-infection with no significant delay induced by the helminth. In contrast, T. retortaeformis intensity decreased faster when co-infected with the bacterium. Simulations suggested that the robust recruitment of neutrophils in the co-infection, added to the activation of IgG and eosinophil driven reduction of larvae, which also played an important role in single infection, contributed to this fast clearance. Perturbation analysis of the models, through the knockout of individual nodes (immune cells), identified the cells critical to parasite persistence and clearance both in single and co-infections. Our integrated approach captured the within-host immuno-dynamics of bacteria-helminth infection and identified key components that can be crucial for explaining individual variability between single and co-infections in natural populations

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

    Get PDF
    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

    Get PDF
    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

    Get PDF
    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry
    corecore