Browsing by Author "Molinari, Aurora"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Copper(II) complex with the tetradentate ligand 1,5-bis (4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methylpyrazolyl)pentane. Liquid-liquid extraction study
    (2006) Oliva, Alfonso; Molinari, Aurora; avila, Carolina; Flores, Maria Fernanda
    The synthesis of the complex and the solvent extraction behaviour of copper(II) from acid solution (pH 0-5) was studied with the new reagent 1,5-bis(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methylpyrazolyl)pentane (H2DTC) as extractant. The reagent acts as tetradentate ligand and the extracted specie was found to be CuDTC.
  • Thumbnail Image
    Item
    Corrosion inhibition of copper in chloride media by 1,5-bis(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methylpyrazolyl)pentane
    (PERGAMON-ELSEVIER SCIENCE LTD, 2008) Vera, Rosa; Bastidas, Francisco; Villarroel, Maria; Oliva, Alfonso; Molinari, Aurora; Ramirez, Daniel; del Rio, Rodrigo
    The efficiency of 1,5-bis(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3-methyl-pyrazolyl)pentane (BDTCPP) as copper corrosion inhibitor in 3.5% NaCl solutions was studied by electrochemical polarization methods (Tafel extrapolation and polarization resistance method), electrochemical impedance spectroscopy and immersion assays. Results obtained in this study reveal that BDTCPP is a good inhibitor and the potentiodynamic polarization studies clearly show that BDTCPP is a mixed-type inhibitor for copper in chloride solutions. It decreases the anodic reaction rate more strongly than the cathodic reaction rate and it renders the open circuit potential of copper more positive in 3.5% NaCl solutions. The UV analysis of the protective layer of BDTCPP after corrosion experiments shows that the inhibitor prevents copper corrosion by physisorption on the metal surface, followed by chemisorption of a protective Cu(II)-complex. This Cu(II) is generated by oxidation of the Cu(I) ion formed at the beginning of the corrosion process in the aerated solution of NaCl. (C) 2007 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    Item
    In vitro evaluation and molecular docking of QS-21 and quillaic acid from Quillaja saponaria Molina as gastric cancer agents
    (NATURE RESEARCH, 2020) Guzman, Leda; Villalon, Katherine; Jose Marchant, Maria; Elena Tarnok, Maria; Cardenas, Pilar; Aquea, Gisela; Acevedo, Waldo; Padilla, Leandro; Bernal, Giuliano; Molinari, Aurora; Corvalan, Alejandro
    The cytotoxic mechanism of the saponin QS-21 and its aglycone quillaic acid (QA) was studied on human gastric cancer cells (SNU1 and KATO III). Both compounds showed in vitro cytotoxic activity with IC50 values: 7.1 mu M (QS-21) and 13.6 mu M (QA) on SNU1 cells; 7.4 mu M (QS-21) and 67 mu M (QA) on KATO III cells. QS-21 and QA induce apoptosis on SNU1 and KATO III, as demonstrated by TUNEL, Annexin-V and Caspase Assays. Additionally, we performed in silico docking studies simulating the binding of both triterpenic compounds to key proteins involved in apoptotic pathways. The binding energies (G(bin)) thus calculated, suggest that the pro-apoptotic protein Bid might be a plausible target involved in the apoptotic effect of both triterpenic compounds. Although QA shows some antiproliferative effects on SNU1 cells cultured in vitro, our results suggest that QS-21 is a more powerful antitumor agent, which merits further investigation regarding their properties as potential therapeutic agents for gastric cancer.