Isolation, Purification and Characterization of Large-Ring Cyclodextrins (CD36∼ ∼CD39)

Abstract

Large-ring cyclodextrins (LR-CDs) composed of more than 9 d-glucose units are not well studied. In this study, LR-CDs composed of 36, 37, 38 and 39 d-glucose units (CD36∼ ∼CD39) were isolated and purified from a LR-CD mixture, and their physicochemical properties including aqueous solubility, surface tension, specific rotation and acid-catalyzed hydrolysis rate were elucidated. The aqueous solubilities of CD36∼ ∼CD39 were greater than those of α-, β-, γ-CD, CD9, CD10, CD14 and CD26. CD36∼ ∼CD39 did not show any surface activity. The acid-catalyzed hydrolysis of CD36∼ ∼CD39 was a little faster than that of other LR-CDs (CD9∼ ∼CD35). There was no marked difference in specific rotation or the acid-catalyzed hydrolysis rate among CD36∼ ∼CD39. Furthermore, we compared these findings with the physicochemical properties of α-, β-, γ-CD and other LR-CDs (CD9∼ ∼CD35).