Mechanism of electron transfer processes photoinduced by lumazine

Autores
Denofrio, María Paula; Dántola, María Laura; Vicendo, Patricia; Oliveros, Esther; Thomas, Andrés Héctor; Lorente, Carolina
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
UV-A (320–400 nm) and UV-B (280–320 nm) radiation causes damage to DNA and other biomolecules through reactions induced by different endogenous or exogenous photosensitizers. Lumazines are heterocyclic compounds present in biological systems as biosynthetic precursors and/or products of metabolic degradation. The parent and unsubstituted compound called lumazine (pteridine-2,4(1,3H)-dione; Lum) is able to act as photosensitizer through electron transfer-initiated oxidations. To get further insight into the mechanisms involved, we have studied in detail the oxidation of 2′-deoxyadenosine 5′-monophosphate (dAMP) photosensitized by Lum in aqueous solution. After UV-A or UV-B excitation of Lum and formation of its triplet excited state (³Lum*), three reaction pathways compete for the deactivation of the latter: intersystem crossing to singlet ground state, energy transfer to O₂, and electron transfer between dAMP and ³Lum* yielding the corresponding pair of radical ions (Lum˙⁻ and dAMP˙⁺). In the following step, the electron transfer from Lum˙⁻ to O₂ regenerates Lum and forms the superoxide anion (O₂˙⁻), which undergoes disproportionation into H₂O₂ and O₂. Finally dAMP˙⁺ participates in subsequent reactions to yield products.
Facultad de Ciencias Exactas
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Materia
Ciencias Exactas
electron transfer
lumazine
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/130519

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network_name_str SEDICI (UNLP)
spelling Mechanism of electron transfer processes photoinduced by lumazineDenofrio, María PaulaDántola, María LauraVicendo, PatriciaOliveros, EstherThomas, Andrés HéctorLorente, CarolinaCiencias Exactaselectron transferlumazineUV-A (320–400 nm) and UV-B (280–320 nm) radiation causes damage to DNA and other biomolecules through reactions induced by different endogenous or exogenous photosensitizers. Lumazines are heterocyclic compounds present in biological systems as biosynthetic precursors and/or products of metabolic degradation. The parent and unsubstituted compound called lumazine (pteridine-2,4(1,3H)-dione; Lum) is able to act as photosensitizer through electron transfer-initiated oxidations. To get further insight into the mechanisms involved, we have studied in detail the oxidation of 2′-deoxyadenosine 5′-monophosphate (dAMP) photosensitized by Lum in aqueous solution. After UV-A or UV-B excitation of Lum and formation of its triplet excited state (³Lum*), three reaction pathways compete for the deactivation of the latter: intersystem crossing to singlet ground state, energy transfer to O₂, and electron transfer between dAMP and ³Lum* yielding the corresponding pair of radical ions (Lum˙⁻ and dAMP˙⁺). In the following step, the electron transfer from Lum˙⁻ to O₂ regenerates Lum and forms the superoxide anion (O₂˙⁻), which undergoes disproportionation into H₂O₂ and O₂. Finally dAMP˙⁺ participates in subsequent reactions to yield products.Facultad de Ciencias ExactasInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas2012info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf409-417http://sedici.unlp.edu.ar/handle/10915/130519enginfo:eu-repo/semantics/altIdentifier/issn/1474-9092info:eu-repo/semantics/altIdentifier/issn/1474-905Xinfo:eu-repo/semantics/altIdentifier/doi/10.1039/c1pp05315ainfo:eu-repo/semantics/altIdentifier/pmid/22212735info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:32:07Zoai:sedici.unlp.edu.ar:10915/130519Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:32:08.31SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Mechanism of electron transfer processes photoinduced by lumazine
title Mechanism of electron transfer processes photoinduced by lumazine
spellingShingle Mechanism of electron transfer processes photoinduced by lumazine
Denofrio, María Paula
Ciencias Exactas
electron transfer
lumazine
title_short Mechanism of electron transfer processes photoinduced by lumazine
title_full Mechanism of electron transfer processes photoinduced by lumazine
title_fullStr Mechanism of electron transfer processes photoinduced by lumazine
title_full_unstemmed Mechanism of electron transfer processes photoinduced by lumazine
title_sort Mechanism of electron transfer processes photoinduced by lumazine
dc.creator.none.fl_str_mv Denofrio, María Paula
Dántola, María Laura
Vicendo, Patricia
Oliveros, Esther
Thomas, Andrés Héctor
Lorente, Carolina
author Denofrio, María Paula
author_facet Denofrio, María Paula
Dántola, María Laura
Vicendo, Patricia
Oliveros, Esther
Thomas, Andrés Héctor
Lorente, Carolina
author_role author
author2 Dántola, María Laura
Vicendo, Patricia
Oliveros, Esther
Thomas, Andrés Héctor
Lorente, Carolina
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
electron transfer
lumazine
topic Ciencias Exactas
electron transfer
lumazine
dc.description.none.fl_txt_mv UV-A (320–400 nm) and UV-B (280–320 nm) radiation causes damage to DNA and other biomolecules through reactions induced by different endogenous or exogenous photosensitizers. Lumazines are heterocyclic compounds present in biological systems as biosynthetic precursors and/or products of metabolic degradation. The parent and unsubstituted compound called lumazine (pteridine-2,4(1,3H)-dione; Lum) is able to act as photosensitizer through electron transfer-initiated oxidations. To get further insight into the mechanisms involved, we have studied in detail the oxidation of 2′-deoxyadenosine 5′-monophosphate (dAMP) photosensitized by Lum in aqueous solution. After UV-A or UV-B excitation of Lum and formation of its triplet excited state (³Lum*), three reaction pathways compete for the deactivation of the latter: intersystem crossing to singlet ground state, energy transfer to O₂, and electron transfer between dAMP and ³Lum* yielding the corresponding pair of radical ions (Lum˙⁻ and dAMP˙⁺). In the following step, the electron transfer from Lum˙⁻ to O₂ regenerates Lum and forms the superoxide anion (O₂˙⁻), which undergoes disproportionation into H₂O₂ and O₂. Finally dAMP˙⁺ participates in subsequent reactions to yield products.
Facultad de Ciencias Exactas
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
description UV-A (320–400 nm) and UV-B (280–320 nm) radiation causes damage to DNA and other biomolecules through reactions induced by different endogenous or exogenous photosensitizers. Lumazines are heterocyclic compounds present in biological systems as biosynthetic precursors and/or products of metabolic degradation. The parent and unsubstituted compound called lumazine (pteridine-2,4(1,3H)-dione; Lum) is able to act as photosensitizer through electron transfer-initiated oxidations. To get further insight into the mechanisms involved, we have studied in detail the oxidation of 2′-deoxyadenosine 5′-monophosphate (dAMP) photosensitized by Lum in aqueous solution. After UV-A or UV-B excitation of Lum and formation of its triplet excited state (³Lum*), three reaction pathways compete for the deactivation of the latter: intersystem crossing to singlet ground state, energy transfer to O₂, and electron transfer between dAMP and ³Lum* yielding the corresponding pair of radical ions (Lum˙⁻ and dAMP˙⁺). In the following step, the electron transfer from Lum˙⁻ to O₂ regenerates Lum and forms the superoxide anion (O₂˙⁻), which undergoes disproportionation into H₂O₂ and O₂. Finally dAMP˙⁺ participates in subsequent reactions to yield products.
publishDate 2012
dc.date.none.fl_str_mv 2012
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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://sedici.unlp.edu.ar/handle/10915/130519
url http://sedici.unlp.edu.ar/handle/10915/130519
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1474-9092
info:eu-repo/semantics/altIdentifier/issn/1474-905X
info:eu-repo/semantics/altIdentifier/doi/10.1039/c1pp05315a
info:eu-repo/semantics/altIdentifier/pmid/22212735
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
409-417
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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