Preparation and Lectin Binding Property of Chitosan–Carbohydrate Conjugates

Chitosan–sialic acid conjugates were prepared using p-formylphenyl α-sialoside by reductive N-alkylation. The degree of substitution (DS) of conjugates could be controlled from 0.06 to 0.53 by the amount of sialoside. With the use of p-isothiocyanatophenyl α-sialoside, chitosan–sialic acid conjugates were also prepared with excellent efficiency. Chitosan–melibiose conjugates having α-galactosyl epitope were also prepared by reductive N-alkylation. These conjugates were transformed into water-soluble forms by N-succinylation and their protein binding property was tested using wheat germ agglutinin (WGA) or Griffonia simplicifolia (GSI-B4) lectin. Strong immunodiffusion bands were observed in all of conjugates, thus demonstrating the specific binding of epitope in conjugate to each lectins.