Complexation of glucose by α- and β-cyclodextrins

Abstract

The concentration of glucose in aqueous solutions was monitored, using a blood glucose meter, as small weighed cyclodextrin portions were added. Equilibrium constants for the formation of inclusion complexes were calculated. A binding constant determined by this method has been verified by a technique involving competition of the guest with methyl orange indicator dye. ΔH 0 values for the reactions were estimated using calorimetry. These values along with ΔG 0 provided estimates of the standard entropies. The values calculated compare favorably with those from a previously determined empirical equation. The possibility of hydrogen bond formation is suggested by the large negative enthalpies as well as by molecular mechanics calculations. Keywords: α-, β-cyclodextrin, glucose, binding constants.