ABSTRACT
X-ray crystallography and nuclear magnetic resonance spectroscopy are the two best known and widely used experimental methods in the conformational studies of carbohydrates. The former is undoubtedly the best and only method to “directly” determine the three-dimensional structure of molecules at atomic detail. The positions of even hydrogen atoms can be unequivocally determined using neutron diffraction. The end-to-end distance of oligosaccharides can be measured by attaching “reporter” probes and by measuring the resonance energy transfer. Fluorescence energy transfer theory was first used by Stryer as a “spectroscopic ruler” to measure the end-to-end distances in oligopeptide. Optical rotation has a great potential in the conformational analysis of carbohydrates as it is sensitive to configuration, conformation and chemical composition. Computational methods have a profound role in the present day conformational analysis. Originally designed for studying hydrocarbons in the gas phase, subsequent developments have made it possible to apply them for the conformational analysis of much larger biological systems.
