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A Strategy for Sensitive, Large Scale Quantitative Metabolomics
Published on: May 27, 2014
La fructosa libre está conformacionalmente bloqueada.
Emilio J Cocinero1, Alberto Lesarri, Patricia Écija
1Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV-EHU), Apartado 644, 48080 Bilbao, Spain. emiliojose.cocinero@ehu.es
Journal of the American Chemical Society
|January 26, 2013
Resumen
La fructosa libre existe en una forma estable de beta-piranosa, a diferencia de su estructura de furanosa en los polisacáridos. Esta conformación se mantiene mediante enlaces de hidrógeno intramoleculares y efectos anoméricos.
Área de la Ciencia:
- Química física es la química física de las cosas.
- La espectroscopia molecular es una técnica de espectroscopia molecular.
- Química de los hidratos de carbono.
Sus antecedentes:
- La fructosa es un monosacárido clave con diversas funciones biológicas.
- Comprender la estructura de molécula libre de la fructosa es crucial para su función bioquímica.
- Estudios anteriores sugirieron flexibilidad conformacional, en contraste con las estructuras observadas en los polisacáridos.
Objetivo del estudio:
- Para determinar la estructura precisa de las moléculas aisladas de fructosa.
- Para investigar las preferencias conformacionales de la fructosa en la fase gaseosa.
- Para comparar la estructura de la fase gaseosa con sus formas en contextos biológicos.
Principales métodos:
- Aislamiento de la fructosa mediante la vaporización láser ultrarrápida con rayos UV.
- Espectroscopia rotacional de alta resolución mediante espectroscopia de microondas con transformación de Fourier (FT-MW).
- Análisis de especies isotópicas (13C y D) para confirmar las asignaciones estructurales.
Principales resultados:
- La fructosa existe exclusivamente en una sola conformación dominante de beta-piranosa en aislamiento.
- Esta conformación presenta una estructura en forma de silla (2)C(5), estabilizada por cinco enlaces de hidrógeno intramoleculares.
- La estructura observada contrasta fuertemente con la forma de furanosa que se encuentra en los polisacáridos como la sacarosa.
Conclusiones:
- La molécula de fructosa libre está conformacionalmente bloqueada, favoreciendo una estructura específica de beta-piranosa.
- La unión de hidrógeno intramolecular y los efectos anómero son claves para su estabilidad.
- Este hallazgo proporciona información crítica sobre el comportamiento de la fructosa a nivel molecular, distinto de sus formas poliméricas.
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