647 research outputs found

    Aqua­(4,4′-bipyridine-κN)bis­(1,4-dioxo-1,4-dihydronaphthalen-2-olato-κ2 O 1,O 2)zinc 4,4′-bipyridine mono­solvate dihydrate

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    The reaction of 2-hy­droxy-1,4-naphtho­quinone and 4,4′-bipyridine with zinc acetate produced the title compound, [Zn(C10H5O3)2(C10H8N2)(H2O)]·C10H8N2·2H2O. The bond lengths and angles around the metal atom indicate a deviation from octa­hedral geometry. The two naphtho­quinone ligands coordinate in a cis fashion, with the 4,4′-bipyridine ligand and the water mol­ecules completing the coordination sphere of the metal atom. The asymmetric unit contains also one free 4,4′-bipyridine mol­ecule and two uncoordinated water mol­ecules. These mol­ecules make contacts with the complex through O—H⋯N and O—H⋯O hydrogen bonds, creating a layer two-dimensional network parallel to (121)

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

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    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

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    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

    Absolute configuration of clemateol

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    The present study reports the determination of absolute stereochemistry of clemateol, an irregular monoterpene containing an epoxy group, which was isolated as the main component from the essential oil of Calea clematidea (Asteraceae). Its absolute stereochemistry was unambiguously established on the basis of detailed nuclear magnetic resonance (NMR) spectroscopic evidence (3JH-H analysis, derivatization as Mosher's esters and nuclear Overhauser effect (NOESY) spectrum) and also by resonance scattering effects in the single crystal X-ray diffraction (XRD) resolution of its (R)-mandelic acid ester derivative.Fil: Pedroso, Marcelo. Universidade Federal de Santa Maria; BrasilFil: Gehn, Adriana Z.. Universidade Federal de Santa Maria; BrasilFil: Stivanin, Mateus L.. Universidade Federal de Santa Maria; BrasilFil: Larghi, Enrique Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Burrow, Robert A.. Universidade Federal de Santa Maria; BrasilFil: Resende, Jackson A. L. C.. Universidade Federal Fluminense; BrasilFil: Da Silva, Ubiratan F.. Universidade Federal de Santa Maria; BrasilFil: Mostardeiro, Marco A.. Universidade Federal de Santa Maria; BrasilFil: Dalcol, Ionara I.. Universidade Federal de Santa Maria; BrasilFil: Morel, Ademir F.. Universidade Federal de Santa Maria; Brasi

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

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    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)]

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    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

    New Multicomponent Forms of the Antiretroviral Nevirapine with Improved Dissolution Performance

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    In the pharmaceutical area, some drugs exhibit physicochemical properties that adversely affect the formulation processes for bioavailability and effectiveness. Nevirapine (NVP) is an antiretroviral drug that presents low aqueous solubility, which directly impacts its bioavailability. Among all possible modifications, multicomponent crystals, such as cocrystals and eutectic compositions, have been successfully used to improve the solubility of drugs. In this work, the propensity of the formation of multicomponent systems of NVP with seven possible coformers were predicted and tested: salicylic acid (SA), 3-hydroxybenzoic acid (3HBZC), 4-hydroxybenzoic acid (4HBZC), saccharin (SAC), theophylline (THEO), caffeine (CAF), and urea (URE). Results indicate that NVP-SA, NVP-SAC, NVP-3HBZC, and NVP-4HBZC are cocrystals, whereas NVP-THEO and NVP-CAF are eutectic materials, and NVP-URE is a solid physical mixture. A temperature-dependent disorder behavior was identified for NVP-SA cocrystal. Dissolution studies for the eutectic materials are reported, evidencing that these materials exhibit a significant increase in NVP dissolution kinetics.Fil: Costa, Rogeria Nunes. Universidade Federal de Sao Paulo; BrasilFil: Reviglio, Ana Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Siedler, Sana. Universidade Federal de Santa Catarina; BrasilFil: Cardoso, Simone G.. Universidade Federal de Santa Catarina; BrasilFil: Garro Linck, Yamila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Monti, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Carvalho, Alexandre Magnus G.. Centro Nacional de Pesquisa em Energia e Materiais; BrasilFil: Resende, Jackson A. L. C.. Universidade Federal do Mato Grosso do Sul; BrasilFil: Chaves, Marcelo H. C.. Fundación Oswaldo Cruz; BrasilFil: Rocha, Helvético Vinícius Antunes. Fundación Oswaldo Cruz; BrasilFil: Choquesillo Lazarte, Duane. Consejo Superior de Investigaciones Científicas; España. Universidad de Granada; EspañaFil: Infantes, Lourdes. Consejo Superior de Investigaciones Científicas; España. Instituto de Química Física Rocasolano; EspañaFil: Cuffini, Silvia Lucia. Universidade de Sao Paulo; Brasi

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

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    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
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