抄録
Chitosan, whose deacetylation degree was 0.95, was N-carboxymethylated and subsequently modified with 6-amino-6-deoxy-β-cyclodextrin. The 1H NMR spectra of the carboxymethylated chitosan (NCMC) and the β-cyclodextrin- modified NCMC (β-CD-NCMC) showed introductions of ca. 8.4 of the carboxymethyl groups and 8.2 of β-CD moieties per 10 units, respectively. β-CD-NCMC was covalently attached to a macroporous silica gel and used as a stationary phase for chiral HPLC separations of 2, 4-dinitrophenyl-α-amino acids and related racemates. The chiral discrimination was influenced more strongly by the size of an alkyl group on the chiral center of the aliphatic amino acids, compared to a Cyclobond I bearing monomeric β-CD molecules. The distance between two aromatic moieties on the aromatic amino acids and related racemates was also discriminated. The strict recognition required the high substitution degree of the β-CD moiety, permitting us to propose a simultaneous inclusion of the 2, 4-dinitrophenyl group and another aromatic substituent or an alkyl group with a proper size into the two adjacent CD cavities on the polymer chain.
