Browsing by Author "201-0010569"
Now showing items 1-20 of 99
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Valenzuela, V.; Santander, P.; Camargo Grandón, Rodrigo; Squella Serrano, Juan; López Alarcón, Camilo; Núñez Vergara, Luis (TAYLOR & FRANCIS, 2004-07)In the present paper, a direct quenching of radical species by a number of synthesized nitrosoaryl 1,4-dihydropyridines and their parent nitroaryl 1,4-dihydropyridines was determined in aqueous media at pH 7.4. These two ...
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Ramírez, Eduardo Alejandro; Zon, María Alicia; Jara Ulloa, Paola Andrea; Squella Serrano, Juan; Núñez Vergara, Luis; Fernández, Héctor (PERGAMON-ELSEVIER SCIENCE LTD, 2010-01-01)We study the thermodynamics and kinetics of the adsorption of a redox couple having quinone nature on glassy carbon electrodes. This couple is produced by the anodic oxidation of mycotoxin ochratoxin A in 10% acetonitrile ...
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Núñez Vergara, Luis; Daza, R.; Zanocco, A.; Squella Serrano, Juan (1983)2-Hydroxy-3-(p-hydroxyphenyl)-6-methylpyrazine (HHMP) is identified as the product obtained by acidic degradation of amoxycillin in the presence of formaldehyde. I.R., n.m.r. and elemental analysis data are reported. The ...
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Núñez Vergara, Luis; Navarrete Encina, Patricio; Salas, S.; Conde, B.; Carbajo, J.; Squella Serrano, Juan; Camargo Grandón, Rodrigo (PERGAMON-ELSEVIER SCIENCE, 2007-05-09)El mass spectra of products of the dihydropyridine Hantzsch synthesis using hydroxy and methoxy aldehydes as starting materials are reported. The reaction products (C-4 hydroxy- and methoxyphenyl-1,4-dihydropyridines and ...
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Díaz Araya, Guillermo; Godoy Oviedo, Luis; Naranjo, Luis; Squella Serrano, Juan; Letelier Muñoz, María Eugenia; Núñez Vergara, Luis (PERGAMON-ELSEVIER SCIENCE, 1998-09)1. Lipid peroxidation in rat brain slices was induced by Fe+3/ascorbate. 2. Brain lipid peroxidation, as measured by malondialdehyde formation, was inhibited by all the tested nitro aryl 1,4-dihydropyridine derivatives ...
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Álvarez Lueje, Alejandro; Pastine Sepúlveda, Javiera; Squella Serrano, Juan; Núñez Vergara, Luis (SOCIEDAD CHILENA DE QUIMICA, 2005-12)In this work an HPLC stability-indicating method was developed and applied to study the hydrolytic behaviour of lovastatin in different simulated fluids. The selected chromatographic conditions were a C-18 column, ...
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Cyclic voltammetric and EPR spectroscopic studies of benzodiazepines: Loprazolam and flunitrazepam Núñez Vergara, Luis; Bollo Dragnic, Soledad; Olea Azar, Claudio; Navarrete-Encina, Patricio; Squella Serrano, Juan (Elsevier, 1997)The present paper reports on the electrochemical characterization by cyclic voltammetry of two 1,4-benzodiazepines, loprazolam and flunitrazepam in protic, aprotic and mixed media. In protic media (ethanol + 15 mM citrate ...
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Ortíz Yáñez, María Eugenia; Núñez Vergara, Luis; Squella Serrano, Juan (ELSEVIER SCIENCE, 2002-02-08)We have studied the O-2/O-2(.-) redox couple on the HMDE in DMSO aprotic media, obtaining optimal conditions of both oxygen concentration and scan rate in order to avoid oscillatory phenomena. By choosing the oxygen ...
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Bollo Dragnic, Soledad; Núñez Vergara, Luis; Squella Serrano, Juan (ELSEVIER SCIENCE, 2004-01-15)PA-824 (2-nitro-6-(4-trifluoromethoxy-benzyloxy)-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine) is being tested as antituberculosis drug. Little is known on the action mechanism of PA-824; however the reduction of the nitro ...
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Bollo Dragnic, Soledad; Núñez Vergara, Luis; Bontá, M.; Chauviere, G.; Perie, J.; Squella Serrano, Juan (ELSEVIER SCIENCE, 2001-09-21)Megazol (2-amino-5-(1-methyl-5-nitro-2-imdazolyl)-1,3,4-thiadiazol, CAS 19622-55-0) and related nitroimidazole compounds are being tested as antichagasic drugs. Little is known on the mode of action of megazol. However, ...
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Carbajo, J.; Bollo Dragnic, Soledad; Núñez Vergara, Luis; Campero, A.; Squella Serrano, Juan (ELSEVIER SCIENCE, 2002-08-23)We have chosen 4-nitroimidazole (4-NIm) as a prototype of nitroimidazolic compounds in order to carry out an exhaustive cyclic voltammetric study in protic media, 0.1 M Britton-Robinson buffer+0.3 M KCl with ethanol as a ...
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Cyclic voltammetry and digital simulation of the electroreducction of ortho-and meta-nitro aryl ... Bollo Dragnic, Soledad; Núñez Vergara, Luis; Squella Serrano, Juan (Sociedad Chilena de Química, 1999)Cyclic voltammetry (CV) and digital simulation methods are utilezed to elucidate the mechanism of electrochemical reduction of a series of nitro aryl 1,4-dihydropyridines im protic (aqueous) and mixed media. The experimental ...
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Bollo Dragnic, Soledad; Finger Caraccioli, Sebastián; Sturm Schaub, Juan; Núñez Vergara, Luis; Squella Serrano, Juan (PERGAMON-ELSEVIER, 2007-04-20)The heterogeneous electron transfer reaction for the reduction of some nitroso aromatic derivatives in aqueous-alcoholic medium was studied on both mercury and glassy carbon electrodes (GCE) by using cyclic voltammetry ...
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Merino, M.; Núñez Vergara, Luis; Squella Serrano, Juan (SOCIEDAD CHILENA DE QUIMICA, 2000-09)Carbon paste electrodes were modified with cytochrome c reductase enzyme. The behavior of the electrodes was characterized by cyclic voltammetry. The cytochrome c reduction was investigated both on the enzyme modified ...
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Fuente Salvat, Elizabeth de la (Universidad de ChilePrograma Cybertesis, 2007)
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Yáñez Soto, Claudia; Núñez Vergara, Luis; Squella Serrano, Juan (WILEY-V C H VERLAG GMBH, 2002-04)Carbon paste electrodes modified with beta-cyclodextrin have been investigated for voltammetric determination of nitrendipine. The immobilization of the beta-cyclodextrin on the carbon paste leads to a modification of the ...
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Álvarez Lueje, Alejandro; Pujol, Silvina; Núñez Vergara, Luis; Squella Serrano, Juan (AOAC INTERNATIONAL, 2002-11)Lercanidipine in ethanol-0.04M Britton-Robinson buffer (20 + 80) gives an irreversible anodic response on a glassy carbon electrode in a broad pH range (2-12) that depends on pH. This signal can be attributed to oxidation ...
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Núñez Vergara, Luis; Yudelevich, J.; Squella Serrano, Juan; Speisky Cosoy, Hernán (Oxford University Press, 1991)Acetaldehyde, at concentrations occurring in vivo was found to avidly react in vitro with several clinically relevant drugs. The greatest reactivity was observed for the hydrazine and hydrazide-containing drugs, hydralazine ...
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Núñez Vergara, Luis; Bollo Dragnic, Soledad; Fuentealba Arcos, Jorge Patricio; Sturm Schaub, Juan; Squella Serrano, Juan (KLUWER ACADEMIC/PLENUM PUBL, 2002-04)Purpose. To characterize the electrochemical behavior of the photodegradation product of nifedipine, i.e., 2,6-dimethyl-4-(2-nitrosophenyl)-3,5-pyridine-carboxylic acid dimethyl ester (NPD) in different electrolytic media. ...
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Núñez Vergara, Luis; Bontá, M.; Sturm, J. C.; Navarrete Encina, Patricio; Bollo Dragnic, Soledad; Squella Serrano, Juan (PERGAMON-ELSEVIER SCIENCE, 2001-08-31)This paper reports a comprehensive study by tast polarography, d.p.p., and cyclic voltammetry on the electrochemical reduction in different electrolytic media of ortho- and meta-nitrotoluene derivatives. Controlled potential ...