22 research outputs found

    Ultrasound-Promoted Synthesis of 3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1carboximidamides and Anticancer Activity Evaluation in Leukemia Cell Lines

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    3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboximidamides were efficiently prepared through a cyclocondensation of thiophenylchalcones with aminoguanidine hydrochloride under ultrasonic conditions in the presence of KOH and ethanol as a green solvent in short reaction times (15-35 min) and good yields (62-95%). All compounds produced were evaluated against the human Jurkat and RS411 acute lymphoblastic leukemia cell lines of T- and B-cell origin, respectively, and the K562 myelogenous leukemia cell line. Six compounds presented half maximal inhibitory concentration (IC50) values around 15 mu mol L-1 and five compounds presented IC50 values around 40 mu mol L-1 for at least one of the three cell lines analyzed. One compound was not significantly cytotoxic, presenting IC50 value > 100 mu mol L- 1.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPESPCNPqFundacao Univ Fed Grande Dourados, Grp Pesquisa Sintese & Caracterizacao Mol MS, Rua Joao Rosa Goes 1761, BR-79825070 Dourados, MS, BrazilUniv Estadual Campinas, Inst Biol, Dept Genet & Biol Mol, Rua Monteiro Lobato 255, BR-13083970 Campinas, SP, BrazilCtr Infantil Boldrini, Mol Biol Lab, Rua Dr Gabriel Porto 1270, BR-13083210 Campinas, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Exatas & Terra, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilUniv Fed Pelotas, Ctr Ciencias Quim Farmaceut & Alimentos, Lab Lipid & Bioorgan, Campus Univ, BR-96001900 Pelotas, RS, BrazilUniv Estadual Mato Grosso do Sul, Rua Emilio Mascolli 275, BR-79950000 Navirai, MS, BrazilUniv Fed Sao Paulo, Dept Ciencias Exatas & Terra, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilCNPq: 483021/2013-0FUNDECT: 0180/12FAPESP: 12/12802-1Web of Scienc

    Synthesis, characterization, and photocatalytic activity of pure and N-, B-, or Ag- Doped TiO2

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    This article reports the synthesis and characterization of pure and N-, B-, and Ag-doped TiO2 and the ability of these oxides to photodegrade methylene blue (MB) under sunlight or UV-ABC radiation. The compounds were synthesized using the sol-gel method and characterized by scanning electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Photocatalytic efficiency was significantly increased by N-doping, resulting in 98% MB decomposition under UV-ABC irradiation for 180 min. Ag- and B-doped TiO2 lowered MB degradation rates to 52 and 73%, respectively, compared with pure TiO2. The same behavior was observed with exposure to UV-Vis, with 88, 65, 60, and 42% MB removal with N-doped, pure, B-doped, and Ag-doped TiO2, respectively. Under visible light alone, N-doped TiO2 exhibited higher photocatalytic efficiency than commercial P25-type TiO2. Photocatalysis with N-doped TiO2 proved to be a promising alternative for MB degradation, given the potential of employing solar energy, thus minimizing operating costs

    Water as an Eco-friendly Solvent for Iodination Reactions of Aromatic and Heteroaromatic Compounds

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    In this review article we have gathered relatively recent publications involving modern methodologies for iodination reactions of aromatic and heteroaromatic compounds using pure water or mixtures containing water as environmentally friendly media.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Fundacao Univ Fed Grande Dourados, Fac Ciencias Exatas & Tecnol, BR-79804970 Dourados, MS, BrazilUniv Fed Sao Paulo, Dept Ciencias Exatas & Terra, Setor Quim, BR-09972270 Diadema, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Exatas & Terra, Setor Quim, BR-09972270 Diadema, SP, BrazilWeb of Scienc

    Efficient and eco-friendly synthesis of iodinated aromatic building blocks promoted by iodine and hydrogen peroxide in water: a mechanistic investigation by mass spectrometry

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    The reaction of aromatic and heteroaromatic compounds with molecular iodine in the presence of aqueous hydrogen peroxide using water without any co-solvent at 50 degrees C for 24 h produced versatile iodinated organic molecules with potential application in organic synthesis and medicine in very good yields. in addition, a mechanistic investigation for the iodination process was carried out by mass spectrometry. (C) 2012 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT)Universidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilFundacao Univ Fed Grande Dourados, Fac Ciencias Exatas & Tecnol, BR-79804970 Dourados, MS, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilWeb of Scienc

    Total Syntheses of Aporphine Alkaloids via Benzyne Chemistry: An Approach to the Formation of Aporphine Cores

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    Total syntheses of lysicamine, (±)-nuciferine, (±)-nornuciferine, (±)-zanthoxyphylline iodide, (±)-<i>O</i>-methylisothebaine, and (±)-trimethoxynoraporphine were accomplished by an approach that involves the formation of aporphine cores through reactions between an isoquinoline derivative and silylaryl triflates promoted by CsF. Unprecedented formations of aporphine cores proceeded in good yields presumably through [4 + 2] cycloaddition reactions followed by hydrogen migrations

    Total Syntheses of Aporphine Alkaloids via Benzyne Chemistry: An Approach to the Formation of Aporphine Cores

    No full text
    Total syntheses of lysicamine, (±)-nuciferine, (±)-nornuciferine, (±)-zanthoxyphylline iodide, (±)-<i>O</i>-methylisothebaine, and (±)-trimethoxynoraporphine were accomplished by an approach that involves the formation of aporphine cores through reactions between an isoquinoline derivative and silylaryl triflates promoted by CsF. Unprecedented formations of aporphine cores proceeded in good yields presumably through [4 + 2] cycloaddition reactions followed by hydrogen migrations

    Highly Electroactive Ni Pyrophosphate/Pt Catalyst toward Hydrogen Evolution Reaction

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    Robust electrocatalysts toward the resourceful and sustainable generation of hydrogen by splitting of water via electrocatalytic hydrogen evolution reaction (HER) are a prerequisite to realize high-efficiency energy research. Highly electroactive catalysts for hydrogen production with ultralow loading of platinum (Pt) have been under exhaustive exploration to make them cutting-edge and cost-effectively reasonable for water splitting. Herein, we report the synthesis of hierarchically structured nickel pyrophosphate (beta-Ni2P2O7) by a precipitation method and nickel phosphate (Ni-3(PO4)(2)) by two different synthetic routes, namely, simple cost-effective precipitation and solution combustion processes. Thereafter, Pt-decorated nickel pyrophosphate and nickel phosphate (beta-Ni2P2O7/Pt and Ni-3(PO4)(2)/Pt) were prepared by using potassium hexachloroplatinate and ascorbic acid. The fabricated novel nickel pyrophosphate and nickel phosphate/Pt materials were utilized as potential and affordable electrocatalysts for HER by water splitting. The detailed electrochemical studies revealed that the beta-Ni2P2O7/Pt (1 mu g.cm(-2) Pt) electrocatalyst showed excellent electrocatalytic performances for HER in acidic solution with an overpotential of 28 mV at -10 mA.cm(-2), a Tafel slope of 32 mV.dec, and an exchange current density (j(0)) of -1.31 mA.cm(-2), which were close to the values obtained using the Vulcan/Pt (8.0 mu g.cm(-2) Pt), commercial benchmarking electrocatalyst with eight times higher Pt amount. Furthermore, the beta-Ni2P2O7/Pt electrocatalyst maintains an excellent stability for over -0.1 V versus RHE for 12 days, keeping j(0) equal after the stability test (-1.28 mA cm(-2)). Very well-distributed Pt NPs inside the cages on the beta-Ni2P2O7 structure with a crystalline pattern of 0.67 nm distance to the Ni2P2O7/Pt electrocatalyst, helping the Volmer-Tafel mechanism with the Tafel reaction as a major rate-limiting step, help to liberate very fast the Pt sites after HER. The high electrocatalytic performance and remarkable durability showed the beta-Ni2P2O7/Pt material to be a promising cost-effective electrocatalyst for hydrogen production
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