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Brito CL, Lins RS, Bertotti M, Ferreira EI, La-Scalea MA. Free radical formation evidence from Nimorazole electrochemical reduction in aqueous media. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2
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Sustainable radical approaches for cross electrophile coupling to synthesize trifluoromethyl- and allyl-substituted tert-alcohols. iScience 2021; 24:103388. [PMID: 34841228 PMCID: PMC8605352 DOI: 10.1016/j.isci.2021.103388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/14/2021] [Accepted: 10/27/2021] [Indexed: 10/27/2022] Open
Abstract
Trifluoromethylated molecules have gained privileged recognition among the medicinal and pharmaceutical chemists. Sustainable photoredox- and electrochemical processes were employed to facilitate the relatively less explored radical cross-electrophile coupling to access trifluoromethyl- and allyl-substituted tert-alcohols. Reactions proceed through trifluoromethyl ketyl radical and allyl radical intermediates, which undergo challenging radical-radical cross-coupling. The developed transformations are mild and chemo-selective to give cross-coupled products and deliver a wide range of valuable trifluoromethyl- and allyl-containing tertiary alcohols. Both processes can also be applied for the synthesis of amine variant containing trifluoromethyl and allyl moiety, which is considered as amide bioisostere.
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Sanz CG, Dias KA, Bacil RP, Serafim RA, Andrade LH, Ferreira EI, Serrano SH. Electrochemical characterization of para- and meta-nitro substituents in aqueous media of new antichagasic pharmaceutical leaders. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2020.137582] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Ghanian Z, Konduri GG, Audi SH, Camara AKS, Ranji M. Quantitative optical measurement of mitochondrial superoxide dynamics in pulmonary artery endothelial cells. JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES 2018; 11:1750018. [PMID: 30123329 PMCID: PMC6097638 DOI: 10.1142/s1793545817500183] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Reactive oxygen species (ROS) play a vital role in cell signaling and redox regulation, but when present in excess, lead to numerous pathologies. Detailed quantitative characterization of mitochondrial superoxide anion ( O2•- ) production in fetal pulmonary artery endothelia cells (PAECs) has never been reported. The aim of this study is to assess mitochondrial O2•- production in cultured PAECs over time using a novel quantitative optical approach. The rate, the sources, and the dynamics of O2•- production were assessed using targeted metabolic modulators of the mitochondrial electron transport chain (ETC) complexes, specifically an uncoupler and inhibitors of the various ETC complexes, and inhibitors of extra-mitochondrial sources of O2•- . After stabilization, the cells were loaded with nanomolar mitochondrial-targeted hydroethidine (Mito-HE, MitoSOX) online during the experiment without washout of the residual dye. Time-lapse fluorescence microscopy was used to monitor the dynamic changes in O2•- fluorescence intensity over time in PAECs. The transient behaviors of the fluorescence time course showed exponential increases in the rate of O2•- production in the presence of the ETC uncoupler or inhibitors. The most dramatic and the fastest increase in O2•- production was observed when the cells were treated with the uncoupling agent, PCP. We also showed that only the complex IV inhibitor, KCN, attenuated the marked surge in O2•- production induced by PCP. The results showed that mitochondrial respiratory complexes I, III and IV are sources of O2•- production in PAECs, and a new observation that ROS production during uncoupling of mitochondrial respiration is mediated in part via complex IV. This novel method can be applied in other studies that examine ROS production under stress condition and during ROS-mediated injuries in vitro.
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Affiliation(s)
- Zahra Ghanian
- Department of Electrical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Girija Ganesh Konduri
- Department of Pediatrics, Division of Neonatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Said Halim Audi
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, USA
| | - Amadou K. S. Camara
- Department of Anesthesiology and Anesthesia Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Mahsa Ranji
- Department of Electrical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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Nuñez-Figueredo Y, Pardo-Andreu GL, Ramírez-Sánchez J, Delgado-Hernández R, Ochoa-Rodríguez E, Verdecia-Reyes Y, Naal Z, Muller AP, Portela LV, Souza DO. Antioxidant effects of JM-20 on rat brain mitochondria and synaptosomes: mitoprotection against Ca²⁺-induced mitochondrial impairment. Brain Res Bull 2014; 109:68-76. [PMID: 25305343 DOI: 10.1016/j.brainresbull.2014.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/25/2014] [Accepted: 10/01/2014] [Indexed: 12/31/2022]
Abstract
Because mitochondrial oxidative stress and impairment are important mediators of neuronal damage in neurodegenerative diseases and in brain ischemia/reperfusion, in the present study, we evaluated the antioxidant and mitoprotective effect of a new promising neuroprotective molecule, JM-20, in mitochondria and synaptosomes isolated from rat brains. JM-20 inhibited succinate-mediated H₂O₂ generation in both mitochondria and synaptosomes incubated in depolarized (high K(+)) medium at extremely low micromolar concentration and with identical IC₅₀ values of 0.91 μM. JM-20 also repressed glucose-induced H₂O₂ generation stimulated by rotenone or by antimycin A in synaptosomes incubated in high sodium-polarized medium at extremely low IC₅₀ values of 0.395 μM and 2.452 μM, respectively. JM-20 was unable to react directly with H₂O₂ or with superoxide anion radicals but displayed a cathodic reduction peak at -0.71V, which is close to that of oxygen (-0.8V), indicating high electron affinity. JM-20 also inhibited uncoupled respiration in mitochondria or synaptosomes and was a more effective inhibitor in the presence of the respiratory substrates glutamate/malate than in the presence of succinate. JM-20 also prevented Ca(2+)-induced mitochondrial permeability transition pore opening, membrane potential dissipation and cytochrome c release, which are key pathogenic events during stroke. This molecule also prevented Ca(2+) influx into synaptosomes and mitochondria; the former effect was a consequence of the latter because JM-20 inhibition followed the patterns of carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP), which is a classic mitochondrial uncoupler. Because the mitochondrion is considered an important source and target of neuronal cell death signaling after an ischemic insult, the antioxidant and protective effects of JM-20 against the deleterious effects of Ca(2+) observed at the mitochondrial level in this study may endow this molecule with the ability to succeed in mitochondrion-targeted strategies to combat ischemic brain damage.
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Affiliation(s)
- Yanier Nuñez-Figueredo
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, La Habana, Cuba
| | - Gilberto L Pardo-Andreu
- Centro de Estudio para las Investigaciones y Evaluaciones Biológicas, Instituto de Farmacia y Alimentos, Universidad de La Habana, Ave 23, No. 21425 e/214 y 222, La Coronela, La Lisa, CP 13600, La Habana, Cuba.
| | - Jeney Ramírez-Sánchez
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, La Habana, Cuba
| | - René Delgado-Hernández
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, La Habana, Cuba
| | - Estael Ochoa-Rodríguez
- Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana, Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, La Habana, Cuba
| | - Yamila Verdecia-Reyes
- Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana, Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, La Habana, Cuba
| | - Zeki Naal
- Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ave. Café s/n, 14040-903 Ribeirão Preto, SP, Brazil
| | - Alexandre Pastoris Muller
- Departamento de Bioquímica, PPG em Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre 90035-003, RS, Brazil
| | - Luis Valmor Portela
- Departamento de Bioquímica, PPG em Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre 90035-003, RS, Brazil
| | - Diogo O Souza
- Departamento de Bioquímica, PPG em Bioquímica, PPG em Educação em Ciência, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre 90035-003, RS, Brazil
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Gál M, Hromadová M, Pospíšil L, Híveš J, Sokolová R, Kolivoška V, Bulíčková J. Voltammetry of hypoxic cells radiosensitizer etanidazole radical anion in water. Bioelectrochemistry 2010; 78:118-23. [DOI: 10.1016/j.bioelechem.2009.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 07/27/2009] [Accepted: 08/15/2009] [Indexed: 11/26/2022]
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Gál M, Híveš J, Sokolová R, Hromadová M, Kolivoška V, Pospíšil L. Impedance study of hypoxic cells radiosensitizer etanidazole radical anion in water. ACTA ACUST UNITED AC 2009. [DOI: 10.1135/cccc2009118] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Electrochemical transfer of the first electron to cytotoxic radiosensitizer etanidazole (ETN) and ETN radical anion formation in the alkaline buffered aqueous solution were studied by means of electrochemical impedance spectroscopy (EIS). The heterogeneous electron transfer rate constant for the first reduction of ETN (radical anion production), k0, was calculated. The value of k0 from EIS measurements and the previously obtained value of so-called E71 potential indicate that ETN, compared with other possible chemical radiosensitizers, requires lower energy to accept the first electron during the metabolic pathway. However, the necessity of the alkaline pH may decrease the ability of ETN to act as hypoxic radiosensitizer in the human body.
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Núñez-Vergara LJ, Salazar R, Camargo C, Carbajo J, Conde B, Navarrete-Encina PA, Squella JA. Oxidation of C4-hydroxyphenyl 1,4-dihydropyridines in dimethylsulfoxide and its reactivity towards alkylperoxyl radicals in aqueous medium. Bioorg Med Chem 2007; 15:4318-26. [PMID: 17446078 DOI: 10.1016/j.bmc.2007.03.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 03/12/2007] [Accepted: 03/14/2007] [Indexed: 11/21/2022]
Abstract
This work reports the electrochemical oxidation of three newly synthesized C4-hydroxyphenyl-substituted 1,4-dihydropyridine derivatives in dimethylsulfoxide. The reactivity of the compounds with ABAP-derived alkylperoxyl radicals in aqueous buffer pH 7.4, was also studied. The oxidation mechanism involves the formation of the unstable dihydropyridyl radical, which was confirmed by controlled-potential electrolysis (CPE) and ESR experiments. The final product of the CPE, that is, pyridine derivative, was identified by GC-MS technique for the three derivatives. A direct reactivity of the synthesized compounds toward ABAP-derived alkylperoxyl radicals was found. The pyridine derivative was identified by GC-MS as the final product of the reaction. Results reveal that this type of 1,4-DHPs significantly reacts with the radicals, even compared with commercial 1,4-DHP drugs with a well-known antioxidant ability.
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Affiliation(s)
- Luis J Núñez-Vergara
- Laboratory of Biolectrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile.
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Julião MSDS, Ferreira EI, Ferreira NG, Serrano SH. Voltammetric detection of the interactions between RNO2− and electron acceptors in aqueous medium at highly boron doped diamond electrode (HBDDE). Electrochim Acta 2006. [DOI: 10.1016/j.electacta.2006.03.054] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Núñez-Vergara LJ, Santander P, Navarrete-Encina P, Squella J. Electrochemical reduction of C-4 nitrosophenyl 1,4-dihydropyridines and their parent C-4 nitrophenyl derivatives in protic media. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2005.03.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Krauth-Siegel RL, Bauer H, Schirmer RH. Dithiol Proteins as Guardians of the Intracellular Redox Milieu in Parasites: Old and New Drug Targets in Trypanosomes and Malaria-Causing Plasmodia. Angew Chem Int Ed Engl 2005; 44:690-715. [PMID: 15657967 DOI: 10.1002/anie.200300639] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Parasitic diseases such as sleeping sickness, Chagas' heart disease, and malaria are major health problems in poverty-stricken areas. Antiparasitic drugs that are not only active but also affordable and readily available are urgently required. One approach to finding new drugs and rediscovering old ones is based on enzyme inhibitors that paralyze antioxidant systems in the pathogens. These antioxidant ensembles are essential to the parasites as they are attacked in the human host by strong oxidants such as peroxynitrite, hypochlorite, and H2O2. The pathogen-protecting system consists of some 20 thiol and dithiol proteins, which buffer the intraparasitic redox milieu at a potential of -250 mV. In trypanosomes and leishmania the network is centered around the unique dithiol trypanothione (N1,N8-bis(glutathionyl)spermidine). In contrast, malaria parasites have a more conservative dual antioxidative system based on glutathione and thioredoxin. Inhibitors of antioxidant enzymes such as trypanothione reductase are, indeed, parasiticidal but they can also delay or prevent resistance against a number of other antiparasitic drugs.
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Affiliation(s)
- R Luise Krauth-Siegel
- Universität Heidelberg, Biochemie-Zentrum, Im Neuenheimer Feld 504, D-69120 Heidelberg, Germany.
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Krauth-Siegel RL, Bauer H, Schirmer RH. Dithiolproteine als Hüter des intrazellulären Redoxmilieus bei Parasiten: alte und neue Wirkstoff-Targets bei Trypanosomiasis und Malaria. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200300639] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Reactions of the nitro radical anion of metronidazole in aqueous and mixed solvent: a cyclic voltammetric study. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2004.02.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Voltammetric studies on nitro radical anion formation from furazolidone and kinetic of the coupled chemical reaction. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2004.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Carbajo J, Bollo S, Núñez-Vergara L, Campero A, Squella J. Cyclic voltammetric study of the disproportionation reaction of the nitro radical anion from 4-nitroimidazole in protic media. J Electroanal Chem (Lausanne) 2002. [DOI: 10.1016/s0022-0728(02)01071-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Núñez-Vergara LJ, Farias D, Bollo S, Squella JA. An electrochemical evidence of free radicals formation from flutamide and its reactivity with endo/xenobiotics of pharmacological relevance. Bioelectrochemistry 2001; 53:103-10. [PMID: 11206916 DOI: 10.1016/s0302-4598(00)00126-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper reports the feasibility of free radicals formation from flutamide by using cyclic voltammetry. The electrochemical characteristics and the reactivity of the one-electron reduction product from flutamide in mixed media with thiol compounds and the nuclei acid bases are characterized. Results from this paper show the thermodynamic feasibility of free radical formation expressed for both the cathodic peak potential and the second-order rate constant values. The reactivity of the radical towards thiol compounds (glutathione, cysteamine, N-acetylcysteine) and the nuclei acid base, adenine, thymine and uracil were quantitatively assessed through the calculation of the respective interaction rate constants. Based on these results, the following tentative order of reactivity towards the xeno/endobiotics is as follows: cysteamine > uracil > glutathione > adenine > N-acetylcysteine > thymine. The stability of the nitro radical anion electrochemically generated from flutamide showed a linear dependence with pH.
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Affiliation(s)
- L J Núñez-Vergara
- Laboratory of Bioelectrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago.
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Carbajo J, Bollo S, Núñez-Vergara L, Navarrete P, Squella J. Voltammetric studies of aromatic nitro compounds: pH-dependence on decay of the nitro radical anion in mixed media. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00343-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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18
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Núñez-Vergara LJ, Squella J, Olea-Azar C, Bollo S, Navarrete-Encina P, Sturm J. Nitrosobenzene: electrochemical, UV-visible and EPR spectroscopic studies on the nitrosobenzene free radical generation and its interaction with glutathione. Electrochim Acta 2000. [DOI: 10.1016/s0013-4686(00)00477-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Núñez-Vergara LJ, Sturm JC, Olea-Azar C, Navarrete-Encina P, Bollo S, Squella JA. Electrochemical, UV--visible and EPR studies on nitrofurantoin: nitro radical anion generation and its interaction with glutathione. Free Radic Res 2000; 32:399-409. [PMID: 10766408 DOI: 10.1080/10715760000300401] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This paper deals with the reactivity of the nitro radical anion electrochemically generated from nitrofurantoin with glutathione. Cyclic voltammetry (CV) and controlled potential electrolysis were used to generate the nitro radical anion in situ and in bulk solution, respectively and cyclic voltammetry, UV--Visible and EPR spectroscopy were used to characterize the electrochemically formed radical and to study its interaction with GSH. By cyclic voltammetry on a hanging mercury drop electrode, the formation of the nitro radical anion was possible in mixed media (0.015M aqueous citrate/DMF, 40/60, pH 9) and in aprotic media. A second order decay of the radicals was determined, with a k2 value of 201 and 111 M(-1) s(-1), respectively. Controlled potential electrolysis generated the radical and its detection by cyclic voltammetry, UV--Visible and EPR spectroscopy was possible. When glutathione (GSH) was added to the solution, an unambiguous decay in the signals corresponding to a nitro radical anion were observed and using a spin trapping technique, a thiyl radical was detected. Electrochemical and spectroscopic data indicated that it is possible to generate the nitro radical anion from nitrofurantoin in solution and that GSH scavenged this reactive species, in contrast with other authors, which previously reported no interaction between them.
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Affiliation(s)
- L J Núñez-Vergara
- Laboratory of Bioelectrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago.
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Squella JA, Gonzalez P, Bollo S, Núñez-Vergara LJ. Electrochemical generation and interaction study of the nitro radical anion from nimesulide. Pharm Res 1999; 16:161-4. [PMID: 9950296 DOI: 10.1023/a:1011950218824] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- J A Squella
- Bioelectrochemistry Laboratory, Chemical and Pharmaceutical Sciences Faculty, University of Chile, Santiago.
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