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Authordc.contributor.authorSilva, E. 
Authordc.contributor.authorJopia, M. 
Authordc.contributor.authorEdwards, A. 
Authordc.contributor.authorLemp Miranda, Else 
Authordc.contributor.authorFuente, Julio de la 
Authordc.contributor.authorLissi Gervaso, Eduardo 
Admission datedc.date.accessioned2018-12-20T15:20:32Z
Available datedc.date.available2018-12-20T15:20:32Z
Publication datedc.date.issued2002
Cita de ítemdc.identifier.citationPhotochemistry and Photobiology, Volumen 75, Issue 6, 2002, Pages 585-590
Identifierdc.identifier.issn00318655
Identifierdc.identifier.other10.1562/0031-8655(2002)075<0585:PEOBAT>2.0.CO;2
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/158815
Abstractdc.description.abstractThe effect of Boldo and black tea infusions on the pro-oxidant effects of vitamin B-2, riboflavin (R-F), when exposed to the action of visible light was studied. The amounts of antioxidants present in Boldo and tea infusions were evaluated by a procedure based on the bleaching of preformed 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cations and were expressed as 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid equivalent concentrations. The quenching rate constants of singlet oxygen (O-1(2); [k(q)](Boldo) = 6.0 X 10(7) M-1 s(-1) and [k(q)](Tea) = 3.2 X 10(7) M-1 s(-1)) and triplet RF ((RF)-R-3; [(3RF)k(q)](Boldo) = 10 X 10(8) M-1 s(-1) and [(3RF)k(q)](TEA) = 3.2 X 10(8) M-1 s(-1)) with Boldo and tea were determined by flash photolysis. These data allow a quantitative interpretation of the results obtained. Our data suggest that most of the oxygen consumption observed in the photolysis or RF in the presence of tea and Boldo infusions is caused by 102 reactions. The oxygen consumption quantum yield is considerably smaller than the fraction of RF triplets trapped by the additives (AH) present in the infusion, indicating that their interaction With 3RF does not lead to chemical reactions or that the AH(.+) radical ions initially formed participate in secondary processes that do not consume oxygen. Boldo and tea infusions have a significant protective effect when a system containing RF and tryptophan (Trp) is exposed to visible light, not only by quenching the O-1(2) and interfering with the Type-l mechanism but also by repairing the damage to Trp molecules associated with the latter mechanism.
Lenguagedc.language.isoen
Sourcedc.sourcePhotochemistry and Photobiology
Keywordsdc.subjectMedicine (all)
Keywordsdc.subjectBiochemistry
Keywordsdc.subjectPhysical and theoretical chemistry
Títulodc.titleProtective effect of boldo and tea infusions on the visible light-mediated pro-oxidant effects of vitamin B2, riboflavin
Document typedc.typeArtículo de revista
dcterms.accessRightsdcterms.accessRightsAcceso a solo metadatos
Catalogueruchile.catalogadorSCOPUS
Indexationuchile.indexArtículo de publicación SCOPUS
uchile.cosechauchile.cosechaSI


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