ISOLATION AND CHARACTERIZATION BY NMR-SPECTROSCOPY OF 3 MONOSUBSTITUTED 4-SULFOBUTYL ETHER DERIVATIVES OF CYCLOMALTOHEPTAOSE (BETA-CYCLODEXTRIN)

The substitution profile of 4-sulfobutyl ether derivatives of cyclomal toheptaose (beta-cyclodextrin) (SBE-beta-CD) prepared in our laborator ies has been previously described. However, in those studies, no attem pt was made to characterize the positional or regional isomers of this material. SBE-beta-CD derivatives with degrees of substitution of two or higher represent a large number of possible isomers dependent on t his positional and regional substitution. The monosubstituted SEE deri vative, however, cannot have regional isomers and, therefore, has only three possible substitution products related to the 2-, 3-, and 6-hyd roxyl groups of a glucose unit. In this study the isomers were fractio nated by preparative anion-exchange chromatography with the progress o f the elution being followed by a capillary electrophoretic (CE) metho d that resolved these isomers. The eluent containing the isomers was p rocessed, and the pure materials were characterized by nuclear magneti c resonance spectroscopy (H-1 NMR, DEFT, HETCOR, HOHAHA). Through this analysis the assignment of the positional isomers was made. (C) 1997 Elsevier Science Ltd.