Energy maps for glycosidic linkage conformations

Abstract

Glycosidic linkage conformations are the main factors in determining the shapes of disaccharide, oligosaccharide, and polysaccharide molecules. The conformations are expressed in terms of the torsion angles about the bonds from each ring of the disaccharide moiety to its glycosidic oxygen atom, and the probability of a given conformation is often expressed in terms of its free or potential energy. The energy surface or map for a disaccharide is a display of the energy plotted against the two torsion angles. Successful mapping allows a particular kind of energy calculation to provide the energy values for each conformation and avoids possible pitfalls. Although different methods are discussed, the main emphasis of this chapter is on the technical production of the maps and their exploitation in further understanding the shape of the molecule in question.