Vitamin B2 - sensitized photooxidation of dopamine
- Autores
- Massad, Walter Alfredo; Barbieri, Yanina; Romero, Mario Raul; García, Norman A.
- Año de publicación
- 2008
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Kinetics and mechanism of the photo-oxidation of the natural catecholamine-type neurotransmitter dopamine (DA) has been studied in aqueous solution, under aerobic conditions, in the presence of riboflavin (Rf, vitamin B2) as a photosensitizer. Results indicate the formation of a weak dark complex Rf–DA, with a mean apparent association constant Kass = 30 M)1 , only detectable at DA concentrations much higher than those employed in photochemical experiments. An intricate mechanism of competitive reactions operates upon photoirradiation. DA quenches excited singlet and triplet states of Rf, with rate constants of 4.2 · 109 and 2.2 · 109 M)1 s )1 , respectively. With the catecholamine in a concentration similar to that of dissolved molecular oxygen in air-saturated water, DA and oxygen competitively quench the triplet excited state of Rf, generating superoxide radical anion (O2 •) ) and singlet molecular oxygen (O2( 1 Dg)) by processes initiated by electron and energy-transfer mechanisms, respectively. Rate constants values of 1.9 · 108 and 6.6 · 106 M)1 s )1 have been obtained for the overall and reactive (chemical) interaction of DA with O2( 1 Dg). The presence of superoxide dismutase increases both the observed rates of aerobic DA photo-oxidation and oxygen uptake, due to its known catalytic scavenging of O2 •) , a species that could revert the overall photo-oxidation effect, according to the proposed reaction mechanism. As in most of the catecholamine oxidative processes described in the literature, aminochrome is the DA oxidation product upon visible light irradiation in the presence of Rf. It is generated with a quantum yield of 0.05.
Fil: Massad, Walter Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina
Fil: Barbieri, Yanina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina
Fil: Romero, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina
Fil: García, Norman A.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina - Materia
-
Photooxidation
Dopamine
Riboflavin
singlet molecular oxygen - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/242111
Ver los metadatos del registro completo
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spelling |
Vitamin B2 - sensitized photooxidation of dopamineMassad, Walter AlfredoBarbieri, YaninaRomero, Mario RaulGarcía, Norman A.PhotooxidationDopamineRiboflavinsinglet molecular oxygenhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Kinetics and mechanism of the photo-oxidation of the natural catecholamine-type neurotransmitter dopamine (DA) has been studied in aqueous solution, under aerobic conditions, in the presence of riboflavin (Rf, vitamin B2) as a photosensitizer. Results indicate the formation of a weak dark complex Rf–DA, with a mean apparent association constant Kass = 30 M)1 , only detectable at DA concentrations much higher than those employed in photochemical experiments. An intricate mechanism of competitive reactions operates upon photoirradiation. DA quenches excited singlet and triplet states of Rf, with rate constants of 4.2 · 109 and 2.2 · 109 M)1 s )1 , respectively. With the catecholamine in a concentration similar to that of dissolved molecular oxygen in air-saturated water, DA and oxygen competitively quench the triplet excited state of Rf, generating superoxide radical anion (O2 •) ) and singlet molecular oxygen (O2( 1 Dg)) by processes initiated by electron and energy-transfer mechanisms, respectively. Rate constants values of 1.9 · 108 and 6.6 · 106 M)1 s )1 have been obtained for the overall and reactive (chemical) interaction of DA with O2( 1 Dg). The presence of superoxide dismutase increases both the observed rates of aerobic DA photo-oxidation and oxygen uptake, due to its known catalytic scavenging of O2 •) , a species that could revert the overall photo-oxidation effect, according to the proposed reaction mechanism. As in most of the catecholamine oxidative processes described in the literature, aminochrome is the DA oxidation product upon visible light irradiation in the presence of Rf. It is generated with a quantum yield of 0.05.Fil: Massad, Walter Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; ArgentinaFil: Barbieri, Yanina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; ArgentinaFil: Romero, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; ArgentinaFil: García, Norman A.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; ArgentinaWiley Blackwell Publishing, Inc2008-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/242111Massad, Walter Alfredo; Barbieri, Yanina; Romero, Mario Raul; García, Norman A.; Vitamin B2 - sensitized photooxidation of dopamine; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 84; 5; 8-2008; 1201-12080031-8655CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-1097.2008.00320.xinfo:eu-repo/semantics/altIdentifier/doi/10.1111/j.1751-1097.2008.00320.xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:02:28Zoai:ri.conicet.gov.ar:11336/242111instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 10:02:29.12CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
Vitamin B2 - sensitized photooxidation of dopamine |
title |
Vitamin B2 - sensitized photooxidation of dopamine |
spellingShingle |
Vitamin B2 - sensitized photooxidation of dopamine Massad, Walter Alfredo Photooxidation Dopamine Riboflavin singlet molecular oxygen |
title_short |
Vitamin B2 - sensitized photooxidation of dopamine |
title_full |
Vitamin B2 - sensitized photooxidation of dopamine |
title_fullStr |
Vitamin B2 - sensitized photooxidation of dopamine |
title_full_unstemmed |
Vitamin B2 - sensitized photooxidation of dopamine |
title_sort |
Vitamin B2 - sensitized photooxidation of dopamine |
dc.creator.none.fl_str_mv |
Massad, Walter Alfredo Barbieri, Yanina Romero, Mario Raul García, Norman A. |
author |
Massad, Walter Alfredo |
author_facet |
Massad, Walter Alfredo Barbieri, Yanina Romero, Mario Raul García, Norman A. |
author_role |
author |
author2 |
Barbieri, Yanina Romero, Mario Raul García, Norman A. |
author2_role |
author author author |
dc.subject.none.fl_str_mv |
Photooxidation Dopamine Riboflavin singlet molecular oxygen |
topic |
Photooxidation Dopamine Riboflavin singlet molecular oxygen |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
Kinetics and mechanism of the photo-oxidation of the natural catecholamine-type neurotransmitter dopamine (DA) has been studied in aqueous solution, under aerobic conditions, in the presence of riboflavin (Rf, vitamin B2) as a photosensitizer. Results indicate the formation of a weak dark complex Rf–DA, with a mean apparent association constant Kass = 30 M)1 , only detectable at DA concentrations much higher than those employed in photochemical experiments. An intricate mechanism of competitive reactions operates upon photoirradiation. DA quenches excited singlet and triplet states of Rf, with rate constants of 4.2 · 109 and 2.2 · 109 M)1 s )1 , respectively. With the catecholamine in a concentration similar to that of dissolved molecular oxygen in air-saturated water, DA and oxygen competitively quench the triplet excited state of Rf, generating superoxide radical anion (O2 •) ) and singlet molecular oxygen (O2( 1 Dg)) by processes initiated by electron and energy-transfer mechanisms, respectively. Rate constants values of 1.9 · 108 and 6.6 · 106 M)1 s )1 have been obtained for the overall and reactive (chemical) interaction of DA with O2( 1 Dg). The presence of superoxide dismutase increases both the observed rates of aerobic DA photo-oxidation and oxygen uptake, due to its known catalytic scavenging of O2 •) , a species that could revert the overall photo-oxidation effect, according to the proposed reaction mechanism. As in most of the catecholamine oxidative processes described in the literature, aminochrome is the DA oxidation product upon visible light irradiation in the presence of Rf. It is generated with a quantum yield of 0.05. Fil: Massad, Walter Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Barbieri, Yanina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Romero, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: García, Norman A.. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina |
description |
Kinetics and mechanism of the photo-oxidation of the natural catecholamine-type neurotransmitter dopamine (DA) has been studied in aqueous solution, under aerobic conditions, in the presence of riboflavin (Rf, vitamin B2) as a photosensitizer. Results indicate the formation of a weak dark complex Rf–DA, with a mean apparent association constant Kass = 30 M)1 , only detectable at DA concentrations much higher than those employed in photochemical experiments. An intricate mechanism of competitive reactions operates upon photoirradiation. DA quenches excited singlet and triplet states of Rf, with rate constants of 4.2 · 109 and 2.2 · 109 M)1 s )1 , respectively. With the catecholamine in a concentration similar to that of dissolved molecular oxygen in air-saturated water, DA and oxygen competitively quench the triplet excited state of Rf, generating superoxide radical anion (O2 •) ) and singlet molecular oxygen (O2( 1 Dg)) by processes initiated by electron and energy-transfer mechanisms, respectively. Rate constants values of 1.9 · 108 and 6.6 · 106 M)1 s )1 have been obtained for the overall and reactive (chemical) interaction of DA with O2( 1 Dg). The presence of superoxide dismutase increases both the observed rates of aerobic DA photo-oxidation and oxygen uptake, due to its known catalytic scavenging of O2 •) , a species that could revert the overall photo-oxidation effect, according to the proposed reaction mechanism. As in most of the catecholamine oxidative processes described in the literature, aminochrome is the DA oxidation product upon visible light irradiation in the presence of Rf. It is generated with a quantum yield of 0.05. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-08 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
format |
article |
status_str |
publishedVersion |
dc.identifier.none.fl_str_mv |
http://hdl.handle.net/11336/242111 Massad, Walter Alfredo; Barbieri, Yanina; Romero, Mario Raul; García, Norman A.; Vitamin B2 - sensitized photooxidation of dopamine; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 84; 5; 8-2008; 1201-1208 0031-8655 CONICET Digital CONICET |
url |
http://hdl.handle.net/11336/242111 |
identifier_str_mv |
Massad, Walter Alfredo; Barbieri, Yanina; Romero, Mario Raul; García, Norman A.; Vitamin B2 - sensitized photooxidation of dopamine; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 84; 5; 8-2008; 1201-1208 0031-8655 CONICET Digital CONICET |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-1097.2008.00320.x info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1751-1097.2008.00320.x |
dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
eu_rights_str_mv |
openAccess |
rights_invalid_str_mv |
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
dc.format.none.fl_str_mv |
application/pdf application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Wiley Blackwell Publishing, Inc |
publisher.none.fl_str_mv |
Wiley Blackwell Publishing, Inc |
dc.source.none.fl_str_mv |
reponame:CONICET Digital (CONICET) instname:Consejo Nacional de Investigaciones Científicas y Técnicas |
reponame_str |
CONICET Digital (CONICET) |
collection |
CONICET Digital (CONICET) |
instname_str |
Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.name.fl_str_mv |
CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas |
repository.mail.fl_str_mv |
dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar |
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1842269757850517504 |
score |
13.13397 |