Photosensitized Oxidation of Oxopurines by Rose Bengal

Photosensitized oxidations of oxopurines (OP) as caffeine, theophylline, theobromine and 1,3,7-trimethyluric acid (TMU) by Rose Bengal were investigated. In all cases photooxidations occur by a type II mechanism. Reactive and nonreactive 1O2 quenching rate constants by OP were determined in differen...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Murgida, D.H., Aramendía, P.F., Erra Balsells, R.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00318655_v68_n4_p467_Murgida
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00318655_v68_n4_p467_Murgida
record_format dspace
spelling todo:paper_00318655_v68_n4_p467_Murgida2023-10-03T14:41:33Z Photosensitized Oxidation of Oxopurines by Rose Bengal Murgida, D.H. Aramendía, P.F. Erra Balsells, R. Photosensitized oxidations of oxopurines (OP) as caffeine, theophylline, theobromine and 1,3,7-trimethyluric acid (TMU) by Rose Bengal were investigated. In all cases photooxidations occur by a type II mechanism. Reactive and nonreactive 1O2 quenching rate constants by OP were determined in different solvents. Based on the correlations of the rate constants with different solvent parameters (α, β, ET[30], AN, DN, π*, ∈), the initial formation of an exciplex between 1O2 and OP is proposed that evolves to a zwitterionic transition state. Some reaction products were characterized, among them 3-methyl-5-(methylamine)-1,5-dehydrohydantoin was obtained as the main photooxidation product of TMU. A reaction mechanism is proposed for the formation of this and other reaction products. Fil:Murgida, D.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Aramendía, P.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Erra Balsells, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00318655_v68_n4_p467_Murgida
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description Photosensitized oxidations of oxopurines (OP) as caffeine, theophylline, theobromine and 1,3,7-trimethyluric acid (TMU) by Rose Bengal were investigated. In all cases photooxidations occur by a type II mechanism. Reactive and nonreactive 1O2 quenching rate constants by OP were determined in different solvents. Based on the correlations of the rate constants with different solvent parameters (α, β, ET[30], AN, DN, π*, ∈), the initial formation of an exciplex between 1O2 and OP is proposed that evolves to a zwitterionic transition state. Some reaction products were characterized, among them 3-methyl-5-(methylamine)-1,5-dehydrohydantoin was obtained as the main photooxidation product of TMU. A reaction mechanism is proposed for the formation of this and other reaction products.
format JOUR
author Murgida, D.H.
Aramendía, P.F.
Erra Balsells, R.
spellingShingle Murgida, D.H.
Aramendía, P.F.
Erra Balsells, R.
Photosensitized Oxidation of Oxopurines by Rose Bengal
author_facet Murgida, D.H.
Aramendía, P.F.
Erra Balsells, R.
author_sort Murgida, D.H.
title Photosensitized Oxidation of Oxopurines by Rose Bengal
title_short Photosensitized Oxidation of Oxopurines by Rose Bengal
title_full Photosensitized Oxidation of Oxopurines by Rose Bengal
title_fullStr Photosensitized Oxidation of Oxopurines by Rose Bengal
title_full_unstemmed Photosensitized Oxidation of Oxopurines by Rose Bengal
title_sort photosensitized oxidation of oxopurines by rose bengal
url http://hdl.handle.net/20.500.12110/paper_00318655_v68_n4_p467_Murgida
work_keys_str_mv AT murgidadh photosensitizedoxidationofoxopurinesbyrosebengal
AT aramendiapf photosensitizedoxidationofoxopurinesbyrosebengal
AT errabalsellsr photosensitizedoxidationofoxopurinesbyrosebengal
_version_ 1807322215967883264

Ejemplares similares