Cyclodextrins cyclomaltodextrins

Structure and stoichiometry. Cyclodextrins (CyDs) were discovered over 100 years ago by Villiers.23 They are formed by Bacillus macerans, which is a type of bacteria that degrades starch,24 using the enzyme cyclomaltodextrin gluconotransferase, or CyD glycosyl transferase.25 CyDs were often called Schardinger dextrins because they were first popularized by Schardinger.26... 

Labeled maltosyl branched-cyclomaltodextrins can be synthesized by the action of isoamylase (19-20) or pullulanase (22,23) with various types of labeled maltose and cyclodextrin. Three types of labeled maltosyl cyclodextrins can be obtained (a) reducing-end labeled maltose attached to cyclodextrin (b) uniformly labeled maltose attached to cyclodextrin and (c) nonlabeled maltose attached to uniformly labeled cyclodextrin (Figure 8). 

The discovery and chemistry of the non-reducing, chemically stable 2-0-a-D-glucopyranosyl-L-ascorbic acid has been reviewed, and a new synthesis of it has been described in which L-ascorbate and a-cyclodextrin interact in the presence of a cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus. Other products with higher maltooligosaccharides linked to 0-2 of the ascorbate were also formed, but glucoamylase could be used to convert these to more 2-0-a-glucopyranosyl-L-ascorbic acid.7 ... 

The internal hydrophobic cavity is the key structural feature of the cyclodex-trins it provides their ability to complex and hold a wide variety of inclusion molecules. Differences between the cyclomaltodextrins arise from differences in the diameters of their cavities. The organic inclusion molecules have alkyl, aromatic, alcohol, and ester groups. To bind with the cyclomaltodextrin, the inclusion molecule must have a size that fits, at least partially, into the cavity, creating the complex. The inclusion compound, however, does not have to be completely contained in the cavity. Complexes can be formed by the insertion of some specific functional group or part of the molecule to bind in the hydrophobic cavity. This partial insertion of the inclusion compound gives a cap or lid on the cavity. Sometimes more than one cyclodextrin will bind with a single inclusion molecule. 

---