Chitosan derivatives bearing pendant cyclodextrin cavities: Synthesis and inclusion performance

A new synthetic route to beta -cyclodextrin-linked chitosan was developed. This was based on the preparation of a monosubstituted beta -cyclodextrin ( beta -CD) derivative possessing a reducing sugar on the primary face follow ed by its reductive amination. The CD-polysaccharide was fully characterize d in terms of chemical integrity and purity by high-resolution NMR and ligh t scattering. The formation of inclusion complexes was investigated by NMR spectroscopy using tert-butylbenzoic acid and (+)-catechin as model guests. Inclusion properties of the grafted beta -CDs were shown to be similar to those of native beta -CD in terms of complex geometry and affinity constant . These results confirm that the pendant beta -cyclodextrin preserves its c onformation and its complexing characteristics.