Isolation, purification and characterization of large-ring cyclodextrins (CD36∼CD39)

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 similar to 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 similar to CD39 were greater than those of alpha-, beta-, gamma-CD, CD9, CD10, CD14 and CD26. CD36 similar to CD39 did not show any surface activity. The acid-catalyzed hydrolysis of CD36 similar to CD39 was a little faster than that of other LR-CDs (CD9 similar to CD35). There was no marked difference in specific rotation or the acid-catalyzed hydrolysis rate among CD36 similar to CD39. Furthermore, we compared these findings with the physicochemical properties of alpha-, beta-, gamma-CD and other LR-CDs (CD9 similar to CD35).