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Conformational Differences Between O- and C-Glycosides: Theα-O-Man-(1→1)-β-Gal/α-C-Man-(1→1)-β-Gal Case- A Decisive Demonstration of the Importance of theexo-Anomeric Effect on the Conformation of Glycosides

2000; Wiley; Volume: 6; Issue: 6 Linguagem: Espanhol

10.1002/(sici)1521-3765(20000317)6

1521-3765

Juan Luis Asensio, F. Javier Cañada, Xuhong Cheng, Noshena Khan, David R. Mootoo, Jesús Jiménez‐Barbero,

Microbial Metabolites in Food Biotechnology

First experimental estimation of theexo-anomeric effect in water solution could be given by the comparison of NMR data for the C-/O-glycoside pair 1 and 2. Tar-MD simulations unequivocally demonstrated the distinct conformational behavior of O- and C-glycosides. The conformational behavior of α-O-Man-(1→1)-β-Gal (1) and its C-analogue (2) has been studied using J/NOE NMR data, molecular mechanics, molecular dynamics, and ab initio calculations. The population distribution around the glycosidic linkages of 1 and 2 is rather different, especially for the α-Man linkage. A lower limit for the exo-anomeric effect in water has been experimentally determined. El comportamiento conformacional del α-O-Man-(1→1)-β-Gal (1) y su análogo C-glicosídico 2 se ha estudiado utilizando una combinación de datos experimentales de RMN y cálculos de mecánica y dinámica molecular y ab initio. La distribución de poblaciones en torno a los enlaces glicosídicos de 1 y 2 es muy distinta, especialmente para el enlace α-Man. Además, se ha determinado experimentalmente un límite inferior para el efecto exo-anomérico en disolución acuosa.