Ability of non-cyclic oligosaccharides to form molecular complexes and its use for chiral separation by capillary...

The binding constants (K) for complexation of the phenyl acetates with linear alpha-1,4-linked dextrins have been determined from the kinetics of the hydrolyses of the esters. The K value tends to increase with increasing the number of the glucopyranose units, suggesting hydrophobic interaction as a binding force. The weak ability of the linear dextrins to form the molecular complexes makes it possible to separate the enantiomers of binaphthyl derivatives such as 1,1'-binaphthyl-2,2'-dicarboxylic acid, 1,1'-binaphthyl-2,2'-diyl hydrogenphosphate and 2,2'-dihydroxy-1,1'-binaphthyl-3,3'-dicarboxylic acid in their anionic forms. Hydrogen bonding as well as hydrophobic interaction is suggested as an essential force for enantioselective complexation between saccharide and anionic binaphthyl.