Affinity chromatography, cyclodextrin

J.A. Lopez-Mas, S.A. Streitenberger, F. Garcia-Carmona and A. Sanchez-Ferrer, Cyclodextrin biospecific-like displacement in dye-affinity chromatography. J.Chromatogr.A, 911(2001) 47-53. 

In affinity chromatography (AFC), (41-46) the cyclodextrins are either immobilized (e.g. on Sepharose gel) or are dissolved in the eluent. This method is mainly applied for the purification of amylolytic enzymes. 

Cyclodextrins (CDs) are a group of stmcturaUy related cyclic (a-l,4)-linked oligosaccharides. These cyclic oligosaccharides consist of (a-l,4)-linked a-D-glucopyranose units and contain a somewhat lipophilic central cavity and a hydrophilic outer surface. CDs can be chemically modified for many different purposes, for example, CDs bound to a polymer carrier have aheady been employed in affinity chromatography because they are able to form inclusion complexes. The most common forms are a-, P-, and y-CDs as illustrated in Figure 6.2. 

Kriegshauser, G and W Liebl (2000). PuUulanase from the hyperthermophilic bacterium Thermotoga maritima Purification by beta-cyclodextrin affinity chromatography. Journal of Chromatography B Biomedical Science and Applications, 737(1-2), 245-251. 

Enantiomers have different affinities for the cyclodextrin cavity, so they separate as they travel through the chromatography column. The chromatogram below shows a chiral separation of a by-product found in pesticides. 

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