Separation and Characterization of Three Positional Isomers of Dimaltosyl-cyclomaltoheptaose(Dimaltosyl-β-cyclodextrin)

Abstract

A mixture of maltosylcyclomaltoheptaoses (maltosyl-β-cyclodextrins, G₂-βCDs) was prepared from maltose and β-cyclodextrin (βCD) through the reverse action of Klebsiella pneumoniae pullulanase. Three positional isomers of dimaltosyl-βCD in the mixture were separated by high-performance liquid chromatography on a reversed phase column and a graphitized carbon column. Their molecular weights were measured by fast-atom bombardment mass spectrometry, and the structures were established by methylation analysis, hydrolysis with glucoamylase to the known compounds, three positional isomers of diglucosyl-βCD, and ¹³C-nuclear magnetic resonance spectroscopy.