Electrochemical Oxidation of Quercetin
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/8295 https://doi.org/10.1002/elan.200302800 |
Resumo: | The mechanism of electrochemical oxidation of quercetin on a glassy carbon electrode has been studied using cyclic, differential pulse and square-wave voltammetry at different pH. It proceeds in a cascade mechanism, related with the two catechol hydroxyl groups and the other three hydroxyl groups which all present electroactivity, and the oxidation is pH dependent. Quercetin also adsorbs strongly on the electrode surface; and the final oxidation product is not electroactive and blocks the electrode surface. The oxidation of the catechol 3prime,4prime-dihydroxyl electron-donating groups, occurs first, at very low positive potentials, and is a two electron two proton reversible reaction. The hydroxyl group oxidized next was shown to undergo an irreversible oxidation reaction, and this hydroxyl group can form a intermolecular hydrogen bond with the neighboring oxygen. The other two hydroxyl groups also have an electron donating effect and their oxidation is reversible. |
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Electrochemical Oxidation of QuercetinThe mechanism of electrochemical oxidation of quercetin on a glassy carbon electrode has been studied using cyclic, differential pulse and square-wave voltammetry at different pH. It proceeds in a cascade mechanism, related with the two catechol hydroxyl groups and the other three hydroxyl groups which all present electroactivity, and the oxidation is pH dependent. Quercetin also adsorbs strongly on the electrode surface; and the final oxidation product is not electroactive and blocks the electrode surface. The oxidation of the catechol 3prime,4prime-dihydroxyl electron-donating groups, occurs first, at very low positive potentials, and is a two electron two proton reversible reaction. The hydroxyl group oxidized next was shown to undergo an irreversible oxidation reaction, and this hydroxyl group can form a intermolecular hydrogen bond with the neighboring oxygen. The other two hydroxyl groups also have an electron donating effect and their oxidation is reversible.2003info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/8295http://hdl.handle.net/10316/8295https://doi.org/10.1002/elan.200302800engElectroanalysis. 15:22 (2003) 1745-1750Brett, Ana Maria OliveiraGhica, Mariana-Emiliainfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2021-09-01T09:18:12Zoai:estudogeral.uc.pt:10316/8295Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:42.353722Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Electrochemical Oxidation of Quercetin |
title |
Electrochemical Oxidation of Quercetin |
spellingShingle |
Electrochemical Oxidation of Quercetin Brett, Ana Maria Oliveira |
title_short |
Electrochemical Oxidation of Quercetin |
title_full |
Electrochemical Oxidation of Quercetin |
title_fullStr |
Electrochemical Oxidation of Quercetin |
title_full_unstemmed |
Electrochemical Oxidation of Quercetin |
title_sort |
Electrochemical Oxidation of Quercetin |
author |
Brett, Ana Maria Oliveira |
author_facet |
Brett, Ana Maria Oliveira Ghica, Mariana-Emilia |
author_role |
author |
author2 |
Ghica, Mariana-Emilia |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Brett, Ana Maria Oliveira Ghica, Mariana-Emilia |
description |
The mechanism of electrochemical oxidation of quercetin on a glassy carbon electrode has been studied using cyclic, differential pulse and square-wave voltammetry at different pH. It proceeds in a cascade mechanism, related with the two catechol hydroxyl groups and the other three hydroxyl groups which all present electroactivity, and the oxidation is pH dependent. Quercetin also adsorbs strongly on the electrode surface; and the final oxidation product is not electroactive and blocks the electrode surface. The oxidation of the catechol 3prime,4prime-dihydroxyl electron-donating groups, occurs first, at very low positive potentials, and is a two electron two proton reversible reaction. The hydroxyl group oxidized next was shown to undergo an irreversible oxidation reaction, and this hydroxyl group can form a intermolecular hydrogen bond with the neighboring oxygen. The other two hydroxyl groups also have an electron donating effect and their oxidation is reversible. |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/8295 http://hdl.handle.net/10316/8295 https://doi.org/10.1002/elan.200302800 |
url |
http://hdl.handle.net/10316/8295 https://doi.org/10.1002/elan.200302800 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Electroanalysis. 15:22 (2003) 1745-1750 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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