| Polysaccharides compose most of the organic matter on earth and are involved in many life processes. The structural diversity of polysaccharides is well reflected in a correspondingly wide range of chemical and physical properties, leading to numerous scientific and technological applications. During the last several years, capillary electrophoresis (CE) has found several applications in the analysis of both neutral and charged polysaccharides. The high resolving power of CE has become valuable in dealing with extremely complex polysaccharide mixtures, but fluorescent labeling of the saccharides at their reducing end is needed for a highly sensitive detection through laser-induced fluorescence.; In this thesis research, hyaluronic acid (HA) mixtures were resolved and characterized through CE using two distinct approaches: (1) molecular sieving through the dense solutions of entangled (neutral) polymers; and (2) an effective end-labeling strategy leading to enhanced frictional characteristics of the labeled solutes during the electrophoretic process. For both modes of CE, the effects of buffer type, ionic strength and gel concentration on migration times and separation selectivity were investigated. A peak-splitting phenomenon observed under some of these conditions has been tentatively attributed to different HA conformations.; Dextrins are another class of polysaccharides which are known for their complexation capacity toward some ligand molecules. As an attractive alternative to other measurement techniques, we have developed an affinity-CE methodology to measure the degree of dextrin complexation with certain pharmaceutically significant molecules. We have also demonstrated a connection between the complexation ability and chiral selectivity in resolving certain racemic mixtures. CE studies have also been correlated with NMR experiments.; We have extended the use of our affinity CE approach to the following studies: (1) In dextran-ligand complexation, we have found that differently linked polysaccharides have different complexing ability for certain molecules. (2) In the complexation of dextrins with polyiodides, we found that the complex formation is highly dependent on an oligosaccharide chain-length and solvating environment. (3) In carbohydratecarbohydrate interactions, we have demonstrated that hydrogen-bonding interaction is the primary force to stabilize a complexation. (4) In sugar-lectin interactions, we have found that differently linked polysaccharides have different affinity to lectin. The core structure of N-linked glycans appears to be a major cause of the sugar-lectin binding behavior, while the sugar residues at the non-reducing ends also participate strongly. |
