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
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/242111
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/242111
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
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 Técnicas2025-09-29T10:18:21Zoai: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:34982025-09-29 10:18:21.667CONICET 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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score 13.069144

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