Properties

α-cyclodextrin	β-cyclodextrin	γ-cyclodextrin

The family of commercially available cyclic malto-ogliosaccharides known as cyclodextrins consist
of three members; α-cyclodextrin consists of six (1—>4)-linked α-D-glucopyranose residues in a ring, whereas β-, and γ-cyclodextrins consist of seven and eight residues in the ring. The resulting coneshaped cylindrical molecules have a hydrophobic cavity and a hydrophilic rim. The latter is due to the hydroxyl groups of the carbohydrate; the secondary hydroxyl groups on carbon atoms 2 and 3 of the glucose residues being on the larger diameter rim whilst the primary hydroxyl groups on carbon atom 6 are on the smaller diameter rim. The diameters of the cavities are such that a single phenyl ring can be accommodated within α-cyclodextrin, whilst the cavities of α-cyclodextrin and α-cyclodextrin can accommodate substituted single phenyl rings and multiple ring systems.