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Use este identificador para citar o ir al link de este elemento: http://hdl.handle.net/1843/80350
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Campo DCValorIdioma
dc.creatorHenrique Fernandes Vieira Victoriapt_BR
dc.creatorDaniele Cristina Ferreirapt_BR
dc.creatorJose Balena Gabriel Filhopt_BR
dc.creatorDayse Carvalho da Silva Martinspt_BR
dc.creatorMauricio Veloso Brant Pinheiropt_BR
dc.creatorGustavo de Almeida Magalhães Sáfarpt_BR
dc.creatorKlaus Wilhelm Heinrich Krambrockpt_BR
dc.date.accessioned2025-02-24T17:45:48Z-
dc.date.available2025-02-24T17:45:48Z-
dc.date.issued2022-
dc.citation.volume180pt_BR
dc.citation.spage143pt_BR
dc.citation.epage152pt_BR
dc.identifier.doihttps://doi.org/10.1016/j.freeradbiomed.2021.12.303pt_BR
dc.identifier.issn0891-5849pt_BR
dc.identifier.urihttp://hdl.handle.net/1843/80350-
dc.description.resumoThe use of spin traps and redox probes coupled with electron paramagnetic resonance (EPR) is a method frequently applied in the evaluation of the efficiency of photosensitizers and photocatalysts in phototherapeutic and photocatalytic processes that involve reactive oxygen species. In this way, the method helps to clarify the mechanism behind photo-induced reactions. Hydroxy-TEMP is a very specific redox probe for selectively identifying and quantifying singlet oxygen (1O2). In this work, the kinetics of radical generated by the oxidation products of the Hydroxy-TEMP redox probe was analyzed from EPR spectra in aqueous solutions of several water-soluble porphyrins ([H2T4MPyP](OTs)4, Na4[H2T4SPP], [H2T2MPyP](OTs)4, [ZnT4MyPyP](OTs)4, [MnT4MyPyP](OTs)5, H2T4CPP, and [H2T4TriMAPP](OTs)4) under white light illumination. Different factors such as the concentration of the redox probe, pH of the medium, and photostability of the porphyrins were evaluated. A systematic study was carried out to reveal the factors associated with stable radical degradation (TEMPOL) by illumination in the visible spectral region in systems containing photosensitizer (porphyrin) and redox probe (Hydroxy-TEMP). With the aid of EPR and gas chromatography coupled with mass spectroscopy (GC-MS) techniques, the mechanism of the radical degradation and the photobleaching of porphyrins were investigated. After successive interactions with the porphyrin in its excited state, in alkaline aqueous solution (pH > 10), the free radical TEMPOL is transformed into TEMPONE until the final diamagnetic product Phorone. A protocol was elaborated to identify and quantify the generation of 1O2 by Hydroxy-TEMP reliably, to avoid possible errors in the interpretation of efficiency of photosensitizers.pt_BR
dc.description.sponsorshipCNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológicopt_BR
dc.description.sponsorshipFAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Geraispt_BR
dc.description.sponsorshipCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorpt_BR
dc.description.sponsorshipFINEP - Financiadora de Estudos e Projetos, Financiadora de Estudos e Projetospt_BR
dc.languageengpt_BR
dc.publisherUniversidade Federal de Minas Geraispt_BR
dc.publisher.countryBrasilpt_BR
dc.publisher.departmentICX - DEPARTAMENTO DE FÍSICApt_BR
dc.publisher.departmentICX - DEPARTAMENTO DE QUÍMICApt_BR
dc.publisher.initialsUFMGpt_BR
dc.relation.ispartofFree Radical Biology and Medicinept_BR
dc.rightsAcesso Restritopt_BR
dc.subjectHydroxy-TEMPpt_BR
dc.subjectSinglet oxygenpt_BR
dc.subjectRedox probept_BR
dc.subjectNitroxyl radicalpt_BR
dc.subjectOxidationpt_BR
dc.subjectPorphyrinspt_BR
dc.subjectDegradationpt_BR
dc.subjectSpin trappingpt_BR
dc.subjectPhotodynamic therapy (PDT)pt_BR
dc.subject.otherRessonância paramagnética eletrônicapt_BR
dc.subject.otherOxigêniopt_BR
dc.subject.otherOxigeniopt_BR
dc.subject.otherPorfirina e compostos de porfirinapt_BR
dc.titleDetection of singlet oxygen by EPR: the instability of the nitroxyl radicalspt_BR
dc.typeArtigo de Periódicopt_BR
dc.url.externahttps://www.sciencedirect.com/science/article/pii/S0891584921011552?via%3Dihubpt_BR
dc.identifier.orcidhttps://orcid.org/0000-0002-4846-2189pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0001-9523-1298pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0003-1641-6476pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0001-6230-2168pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0001-5722-6260pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0003-1354-3138pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0002-7562-0285pt_BR
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