Mechanism of photooxidation of folic acid sensitized by unconjugated pterins

Autores
Dántola, María Laura; Denofrio, María Paula; Zurbano, Beatriz N.; Giménez, Carlos Sebastián; Ogilby, Peter R.; Lorente, Carolina; Thomas, Andrés Héctor
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Folic acid, or pteroyl-L-glutamic acid (PteGlu), is a precursor of coenzymes involved in the metabolism of nucleotides and amino acids. PteGlu is composed of three moieties: a 6-methylpterin (Mep) residue, a p-aminobenzoic acid (PABA) residue, and a glutamic acid (Glu) residue. Accumulated evidence indicates that photolysis of PteGlu leads to increased risk of several pathologies. Thus, a study of PteGlu photodegradation can have significant ramifications. When an air-equilibrated aqueous solution of PteGlu is exposed to UV-A radiation, the rate of the degradation increases with irradiation time. The mechanism involved in this “auto-photo-catalytic” effect was investigated in aqueous solutions using a variety of tools. Whereas PteGlu is photostable under anaerobic conditions, it is converted into 6-formylpterin (Fop) and p-aminobenzoyl-L-glutamic acid (PABA-Glu) in the presence of oxygen. As the reaction proceeds and enough Fop accumulates in the solution, a photosensitized electron-transfer process starts, where Fop photoinduces the oxidation of PteGlu to Fop, and H₂O₂ is formed. This process also takes place with other pterins as photosensitizers. The results are discussed with the context of previous mechanisms for processes photosensitized by pterins, and their biological implications are evaluated.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Materia
Ciencias Exactas
Química
folic acid
photooxidation
pterins
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/144468

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spelling Mechanism of photooxidation of folic acid sensitized by unconjugated pterinsDántola, María LauraDenofrio, María PaulaZurbano, Beatriz N.Giménez, Carlos SebastiánOgilby, Peter R.Lorente, CarolinaThomas, Andrés HéctorCiencias ExactasQuímicafolic acidphotooxidationpterinsFolic acid, or pteroyl-L-glutamic acid (PteGlu), is a precursor of coenzymes involved in the metabolism of nucleotides and amino acids. PteGlu is composed of three moieties: a 6-methylpterin (Mep) residue, a p-aminobenzoic acid (PABA) residue, and a glutamic acid (Glu) residue. Accumulated evidence indicates that photolysis of PteGlu leads to increased risk of several pathologies. Thus, a study of PteGlu photodegradation can have significant ramifications. When an air-equilibrated aqueous solution of PteGlu is exposed to UV-A radiation, the rate of the degradation increases with irradiation time. The mechanism involved in this “auto-photo-catalytic” effect was investigated in aqueous solutions using a variety of tools. Whereas PteGlu is photostable under anaerobic conditions, it is converted into 6-formylpterin (Fop) and p-aminobenzoyl-L-glutamic acid (PABA-Glu) in the presence of oxygen. As the reaction proceeds and enough Fop accumulates in the solution, a photosensitized electron-transfer process starts, where Fop photoinduces the oxidation of PteGlu to Fop, and H₂O₂ is formed. This process also takes place with other pterins as photosensitizers. The results are discussed with the context of previous mechanisms for processes photosensitized by pterins, and their biological implications are evaluated.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas2010-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1604-1612http://sedici.unlp.edu.ar/handle/10915/144468enginfo:eu-repo/semantics/altIdentifier/issn/1474-9092info:eu-repo/semantics/altIdentifier/issn/1474-905Xinfo:eu-repo/semantics/altIdentifier/doi/10.1039/c0pp00210kinfo:eu-repo/semantics/altIdentifier/pmid/20922252info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T11:04:24Zoai:sedici.unlp.edu.ar:10915/144468Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 11:04:24.489SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
title Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
spellingShingle Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
Dántola, María Laura
Ciencias Exactas
Química
folic acid
photooxidation
pterins
title_short Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
title_full Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
title_fullStr Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
title_full_unstemmed Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
title_sort Mechanism of photooxidation of folic acid sensitized by unconjugated pterins
dc.creator.none.fl_str_mv Dántola, María Laura
Denofrio, María Paula
Zurbano, Beatriz N.
Giménez, Carlos Sebastián
Ogilby, Peter R.
Lorente, Carolina
Thomas, Andrés Héctor
author Dántola, María Laura
author_facet Dántola, María Laura
Denofrio, María Paula
Zurbano, Beatriz N.
Giménez, Carlos Sebastián
Ogilby, Peter R.
Lorente, Carolina
Thomas, Andrés Héctor
author_role author
author2 Denofrio, María Paula
Zurbano, Beatriz N.
Giménez, Carlos Sebastián
Ogilby, Peter R.
Lorente, Carolina
Thomas, Andrés Héctor
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Química
folic acid
photooxidation
pterins
topic Ciencias Exactas
Química
folic acid
photooxidation
pterins
dc.description.none.fl_txt_mv Folic acid, or pteroyl-L-glutamic acid (PteGlu), is a precursor of coenzymes involved in the metabolism of nucleotides and amino acids. PteGlu is composed of three moieties: a 6-methylpterin (Mep) residue, a p-aminobenzoic acid (PABA) residue, and a glutamic acid (Glu) residue. Accumulated evidence indicates that photolysis of PteGlu leads to increased risk of several pathologies. Thus, a study of PteGlu photodegradation can have significant ramifications. When an air-equilibrated aqueous solution of PteGlu is exposed to UV-A radiation, the rate of the degradation increases with irradiation time. The mechanism involved in this “auto-photo-catalytic” effect was investigated in aqueous solutions using a variety of tools. Whereas PteGlu is photostable under anaerobic conditions, it is converted into 6-formylpterin (Fop) and p-aminobenzoyl-L-glutamic acid (PABA-Glu) in the presence of oxygen. As the reaction proceeds and enough Fop accumulates in the solution, a photosensitized electron-transfer process starts, where Fop photoinduces the oxidation of PteGlu to Fop, and H₂O₂ is formed. This process also takes place with other pterins as photosensitizers. The results are discussed with the context of previous mechanisms for processes photosensitized by pterins, and their biological implications are evaluated.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
description Folic acid, or pteroyl-L-glutamic acid (PteGlu), is a precursor of coenzymes involved in the metabolism of nucleotides and amino acids. PteGlu is composed of three moieties: a 6-methylpterin (Mep) residue, a p-aminobenzoic acid (PABA) residue, and a glutamic acid (Glu) residue. Accumulated evidence indicates that photolysis of PteGlu leads to increased risk of several pathologies. Thus, a study of PteGlu photodegradation can have significant ramifications. When an air-equilibrated aqueous solution of PteGlu is exposed to UV-A radiation, the rate of the degradation increases with irradiation time. The mechanism involved in this “auto-photo-catalytic” effect was investigated in aqueous solutions using a variety of tools. Whereas PteGlu is photostable under anaerobic conditions, it is converted into 6-formylpterin (Fop) and p-aminobenzoyl-L-glutamic acid (PABA-Glu) in the presence of oxygen. As the reaction proceeds and enough Fop accumulates in the solution, a photosensitized electron-transfer process starts, where Fop photoinduces the oxidation of PteGlu to Fop, and H₂O₂ is formed. This process also takes place with other pterins as photosensitizers. The results are discussed with the context of previous mechanisms for processes photosensitized by pterins, and their biological implications are evaluated.
publishDate 2010
dc.date.none.fl_str_mv 2010-12
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/10915/144468
url http://sedici.unlp.edu.ar/handle/10915/144468
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/c0pp00210k
info:eu-repo/semantics/altIdentifier/pmid/20922252
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
1604-1612
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