CARB 4 |
| Theoretical studies of aldofuranose rings using quantum mechanical methods have been used to study the effects of molecular structure on NMR parameters such as spin-spin coupling constants. The inherent flexibility of these rings (pseudorotation) renders them valuable in investigations requiring systematic and continuous alteration of the relative positions of ring substituents without the need to break bonds. Information derived from these systems over the past 15 years has helped interpret results from recent and related studies of aldopyranosyl rings. In the present work, we investigated, using DFT methods, the effect of orientation (quasi-axial vs quasi-equatorial) on the acid dissociation constants of hydroxyl groups of furanosyl rings. We were interested in this problem due to the proposed role of the ribonucleotide 2'-OH group in the mechanism of ribozyme catalysis. These studies also yielded new insights into the mechanism of furanose anomerization, specifically whether discrete conformations of furanose rings are more prone to ring-opening (and presumably ring-closing) than others. |
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Implications of Sugar Ring Conformations in Drug Design: A Symposium in Memory of Muttaiya Sundaralingam
2:00 PM-5:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- B409, Oral
Division of Carbohydrate Chemistry |