Catechin electrochemical oxidation mechanisms
Autor(a) principal: | |
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Data de Publicação: | 2004 |
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/10316/5128 https://doi.org/10.1016/j.aca.2004.05.038 |
Resumo: | The oxidation of flavonoids is of great interest because of their action as antioxidants with the ability to scavenge radicals by electron transfer processes. The electrochemical oxidation of the flavonoid (+)-catechin, was investigated, over a wide range of conditions, using cyclic, differential and square wave voltammetry. The oxidation mechanism proceeds in sequential steps, related with the catechol and resorcinol groups and the oxidation is pH dependent. The oxidation of the catechol 3',4'-dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. The hydroxyl groups of the resorcinol moiety oxidised afterwards were shown to undergo an irreversible oxidation reaction. (+)-Catechin also adsorbs strongly on the electrode surface and the final oxidation product is not electroactive and blocks the electrode surface. |
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Catechin electrochemical oxidation mechanismsCatechinElectrochemistryOxidationRadical scavenging activityFlavonoidsFree radicalsThe oxidation of flavonoids is of great interest because of their action as antioxidants with the ability to scavenge radicals by electron transfer processes. The electrochemical oxidation of the flavonoid (+)-catechin, was investigated, over a wide range of conditions, using cyclic, differential and square wave voltammetry. The oxidation mechanism proceeds in sequential steps, related with the catechol and resorcinol groups and the oxidation is pH dependent. The oxidation of the catechol 3',4'-dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. The hydroxyl groups of the resorcinol moiety oxidised afterwards were shown to undergo an irreversible oxidation reaction. (+)-Catechin also adsorbs strongly on the electrode surface and the final oxidation product is not electroactive and blocks the electrode surface.http://www.sciencedirect.com/science/article/B6TF4-4CPVN81-3/1/c7b4097d6e3ec656a0b5f76f9dc0220f2004info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleaplication/PDFhttp://hdl.handle.net/10316/5128http://hdl.handle.net/10316/5128https://doi.org/10.1016/j.aca.2004.05.038engAnalytica Chimica Acta. 518:1-2 (2004) 109-115Janeiro, PatriciaBrett, Ana Maria Oliveirainfo: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:RCAAP2020-11-06T16:48:43Zoai:estudogeral.uc.pt:10316/5128Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:37.894766Repositório 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 |
Catechin electrochemical oxidation mechanisms |
title |
Catechin electrochemical oxidation mechanisms |
spellingShingle |
Catechin electrochemical oxidation mechanisms Janeiro, Patricia Catechin Electrochemistry Oxidation Radical scavenging activity Flavonoids Free radicals |
title_short |
Catechin electrochemical oxidation mechanisms |
title_full |
Catechin electrochemical oxidation mechanisms |
title_fullStr |
Catechin electrochemical oxidation mechanisms |
title_full_unstemmed |
Catechin electrochemical oxidation mechanisms |
title_sort |
Catechin electrochemical oxidation mechanisms |
author |
Janeiro, Patricia |
author_facet |
Janeiro, Patricia Brett, Ana Maria Oliveira |
author_role |
author |
author2 |
Brett, Ana Maria Oliveira |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Janeiro, Patricia Brett, Ana Maria Oliveira |
dc.subject.por.fl_str_mv |
Catechin Electrochemistry Oxidation Radical scavenging activity Flavonoids Free radicals |
topic |
Catechin Electrochemistry Oxidation Radical scavenging activity Flavonoids Free radicals |
description |
The oxidation of flavonoids is of great interest because of their action as antioxidants with the ability to scavenge radicals by electron transfer processes. The electrochemical oxidation of the flavonoid (+)-catechin, was investigated, over a wide range of conditions, using cyclic, differential and square wave voltammetry. The oxidation mechanism proceeds in sequential steps, related with the catechol and resorcinol groups and the oxidation is pH dependent. The oxidation of the catechol 3',4'-dihydroxyl electron-donating groups occurs first, at very low positive potentials, and is a reversible reaction. The hydroxyl groups of the resorcinol moiety oxidised afterwards were shown to undergo an irreversible oxidation reaction. (+)-Catechin also adsorbs strongly on the electrode surface and the final oxidation product is not electroactive and blocks the electrode surface. |
publishDate |
2004 |
dc.date.none.fl_str_mv |
2004 |
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/10316/5128 http://hdl.handle.net/10316/5128 https://doi.org/10.1016/j.aca.2004.05.038 |
url |
http://hdl.handle.net/10316/5128 https://doi.org/10.1016/j.aca.2004.05.038 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Analytica Chimica Acta. 518:1-2 (2004) 109-115 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
aplication/PDF |
dc.source.none.fl_str_mv |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
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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1799133907380076544 |