Isolation and characterization of heptakis(2,6-di- O-methyl)cyclomaltoheptaose and over-methylated homologues

Abstract

From a mixture of methylation products of cyclomaltoheptaose (β-cyclodextrin, βCD) containing heptakis(2,6-di- O-methyl)-βCD ( 1) and its over-methylated homologues, two major components [ 1 and hexakis(2,6-di- O-methyl)-(2,3,6-tri- O-methyl)-βCD ( 2)] and fourteen minor components were isolated by h.p.l.c. The solubilities and inclusion behaviour of 1 and a commercial DM-βCD (a mixture containing 1 and 2) were compared. A 3- O-methyl group had little effect on the inclusion behaviour of 2,6-di- O-methyl-βCD. Fourteen minor over-methylated homologues were characterized.