Browsing by Author "Arancibia, Veronica"

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    ANTIPROLIFERATIVE ACTIVITY OF NEW 6-BROMINE DERIVATIVES OF 7-ANILINO-1-ARYLISOQUINOLINEQUINONES
    (2016) Andrea Ibacache, Juana; Valderrama, Jaime A.; Arancibia, Veronica; Theoduloz, Cristina; Muccioli, Giulio G.; Benites, Julio
    A variety of 6-bromine-containing 7-anilino-1-arylisoquinolinequinones 2a-g were synthesized to evaluate their half-wave potentials and in vitro antiproliferative activity on gastric and leukemia cancer cell lines. The new compounds displayed significant IC50 values in the range: 1.31 to 11.04 mu M. The structure activity relationship analysis of the new series suggest that the antiproliferative activity is dependent, in part, on the push-pull electronic effects of the nitrogen and bromine substituents inserted into the redox fragment of the 1-arylisoquinolinequinone scaffold. Linear regression analysis provided satisfactory relationships between the log IC50 and ClogP values for the AGS gastric cancer cell line.
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    Development of Electroanalytical Methods Using Different Electrodes for the Determination of Progesterone (P4) in Pharmaceutical Formulations and Human, Cow and Goat Milk
    (2023) Cruz, Victoria; Trivino, Juan Jose; Arancibia, Veronica
    For the determination of progesterone (P4) electroanalytical studies were performed using mercury electrode (HMDE) and screen-printed boron-doped diamond electrode (BDD-SPE). The effects of pH, supporting electrolyte, accumulation potential and time (E-acc, t(acc)) were studied in both systems. The optimum conditions were: i) HMDE: pH 7,0; -0,1 V and t(acc): 40 s, ii) BDD-SPE: 0,5 mol L-1 H2S ; E-acc: 0,0 V and t(acc): 120 s. Under these conditions, the detection limit was 3.1 mu g L-1 for HMDE and 45.6 mu g L-1 for BDD-SPE. Both methods were validated and applied in the P4 determination on pharmaceutical formulations and milk samples.
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    Simultaneous Determination of Antimony(III) and Molybdenum(VI) by Adsorptive Stripping Voltammetry Using Quercetin as Complexing Agent
    (2013) Rojas, Carlos; Arancibia, Veronica; Gomez, Marisol; Nagles, Edgar
    A sensitive and selective voltammetric method for simultaneous determination of Sb(III) and Mo(VI) using Quercetin (Q) as complexing agent is described. Optimal conditions were found to be: pH3.7, CQ=6.0 mu molL1 and Eacc=0.10V. The LOD (3 sigma) for Sb(III) are 0.076 and 0.040 mu gL1, whereas for Mo(VI) are 0.086 and 0.048 mu gL1 with tacc of 60 and 120s, respectively. The method was validated using synthetic sea water (ASTM D665) and was applied to the determination of Sb(III) and Mo(VI) in natural waters with satisfactory results.
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    Voltammetric method for the determination of Pb2+ and Cd2+ in water samples using a nafion-guanine-coated mercury film electrode
    (2022) Jose Trivino, Juan; Nunez, Claudia; Merino-San Martin, Ignacio; Zuniga, Manuel; Arancibia, Veronica
    A sensitive voltammetric method is reported for the simultaneous determination of Pb2+ and Cd2+ using a nafion-guanine-coated mercury film glassy carbon electrode. This modified electrode exhibited well-developed signals for the reduction of the adsorbed complexes Pb-Guanine and Cd-Guanine, at -0.59 and -0.76 V respectively. The effects of parameters such as pH, accumulation potential and time (E-acc, t(acc)) were optimized. These studies were done using metallic ions on their own and also mixed together. The best pH for the individual analysis of Pb2+ or Cd2+ were 2.2 and 6.1 respectively, whereas a pH of 5.0 (acetate buffer 0.01 mol L-1) was chosen for simultaneous determination. Under the optimized conditions (pH = 5.0; t(acc) = 60 s; E-acc = -1.0 V) reduction signal was found to be proportional to the concentration of Pb2+ and Cd2+ over the 6.6-35.0 mu g L-1 range, with 36 detection limits (DL) of 2.2 and 4.6 mu g L-1. However, for lower concentrations, a time of 120 s was applied, yielding a linear range from 0.5 to 12.0 mu g L-1 with DLs of 0.26 and 0.25 mu g L-1 for Pb2+ and Cd2+, respectively. If the guanine (G) is in the solution, the signals are much lower than in the modified electrode. The method was validated by determining Pb2+ and Cd2+ in certified reference material (GBW08607) and synthetic sea water (ASTM D665), spiked with 22 metal ions, with satisfactory results. Subsequently, the method was applied in bottled mineral waters and sea water samples without previous treatment.