Enantioseparation on 3,5-dichloro- and 3,5-dimethylphenylcarbamates of polysaccharides as chiral stationary phases for high-performance liquid chromatography

Abstract

3,5-Dichloro- and 3,5-dimethylphenylcarbamates of polysaccharides such as chitosan, galactosamine, xylan, curdlan, dextran, and inulin were prepared and their chiral recognition abilities as chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC) were evaluated and compared with those of the corresponding phenylcarbamate derivatives of cellulose and amylose. Chiral recognition abilities of the phenylcarbamates of polysaccharides depended markedly on the nature of monosaccharide units, the linkage position, and the linkage type. Among the polysaccharide derivatives prepared in this study, the 3,5-dimethylphenylcarbamates of chitosan and xylan and the 3,5-dichlorophenylcarbamate of galactosamine showed relatively high chiral recognition ability, although the 3,5-dimethylphenylcarbamates of cellulose and amylose often exhibited better chiral resolving power. However, some racemates were better resolved on the new phenylcarbamates than the corresponding cellulose and amylose derivatives. Some chiral drugs were also better resolved on xylan bis(3,5-dimethyl- or 3,5-dichlorophenylcarbamate).