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Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides
Published on: July 26, 2018
Escisión del enlace glucosídico de la timidina por electrones de baja energía
Yi Zheng1, Pierre Cloutier, Darel J Hunting
1Canadian Institutes of Health Research Group in the Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC, Canada J1H 5N4.
Journal of the American Chemical Society
|January 30, 2004
Resumen
Los electrones de baja energía (LEE) que interactúan con la timidina crean timina, un producto importante del daño del ADN. Esto sugiere un nuevo mecanismo de daño al ADN a través de la escisión de enlaces inducida por electrones, distinta de las reacciones de ionización o de electrones solvados.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Química de la radiación Química de la radiación
- Biología Molecular Biología Molecular
Sus antecedentes:
- El daño del ADN es un factor crítico en la función celular y la enfermedad.
- Comprender los mecanismos de daño del ADN inducido por la radiación es crucial para la protección y la terapia radiológica.
- Estudios anteriores se centraron en las reacciones de ionización o de electrones solvados.
Objetivo del estudio:
- Para investigar la interacción de los electrones de baja energía (LEE) con la timidina.
- Para identificar los productos de radiación formados por la exposición a LEE.
- Para dilucidar el mecanismo de daño de la base del ADN por LEE.
Principales métodos:
- Exposición de películas de timidina en estado sólido a LEE (3-100 eV) bajo alto vacío.
- Análisis de productos de radiación no volátil utilizando cromatografía líquida de alto rendimiento con detección ultravioleta (HPLC/UV).
- Cromatografía de gases y espectrometría de masas (GC/MS) para la identificación de productos.
Principales resultados:
- La timina fue identificada como el principal producto de la descomposición de la timidina por LEE.
- El rendimiento de la formación de timina fue de 3,2 x 10^-2 por electrón.
- La formación de timina inducida por LEE sugiere la escisión del enlace glucósido a través de un proceso de resonancia no ionizante (<15 eV).
Conclusiones:
- La exposición a LEE induce una nueva vía de daño del ADN que involucra la descomposición de la timidina.
- Este mecanismo, que implica la fijación disociativa de electrones, difiere de la ionización de la base de ADN o de las reacciones de electrones solvados.
- Los hallazgos destacan una nueva vía para el daño al ADN inducido por LEE.
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