Preparation And Enatioseparation Capability Of Chiral Stationary Phases Of Polysaccharides Derivatives And Pirkle Types

The significant difference between a pair of enantiomers of chiral drugs inpharmacologic action and physiological activity makes enantioseparation be one of theresearch hotspots in the fields of separation and analysis. High-performance liquidchromatography (HPLC) based on chiral stationary phase (CSP) has become a besttechnique to separate and detect enantiomers, because of its high efficiency and speediness.CSP is the kernel of this technology. In order to broaden the application scope of CSP, andto find CSPs with good chiral recognition ability and durability, several new CSPs weredesigned and prepared in this work. The enantioseparation ability of the as-prepared CSPswas evaluated. The works are summarized as follows:(1) Four new chitin derivatives, which is chitin bis(4-trifluoro-methoxylphenylcarbamate), chitin bis(3-chloro-4-methylphenylcarbamate), chitin bis(4-chloro-3-trifluoromethylphenylcarbamate) and chitin bis-(5-chloro-2-methylphenyl-carbamate)were prepared, and characterized by FT-IR and element analysis. These chitin derivativeswere dissolved in appropriate solvents and were then coated on3-aminopropy silica gel,respectively, to give corresponding CSPs. The effect of the coating amount of chitinderivatives on the silica gel and solvent composition of the mobile phases on the chiralrecognition ability of these CSPs was studied. Besides, the separation properties of eachstationary phase were discussed in deep. The overall result showed that, chitin derivativesCSPs had the advantages of satisfactory chiral recognition ability and durability.Moreover, they could be used in a variety of mobile phases and organic additives, such aschloroform, ethyl acetate etc, for its very low solubility in common organic solvents.(2) Two composite CSPs were prepared by coating a mixture of chitinbis(3-chloro-4-methylphenylcarbamate) and amylose tris(3,5-dimethylphenylcarbamate)on3-aminopropyl silica gel at two molar ratios (glucose unit) of1:4and1:1respectively.The result showed that the enantioseparation abilities of the two composite CSPsgenerally intermediated between those of the two individual phases. However, the durability of the composite CSPs was better than that of single chiral selector CSP ofamylose derivative.(3) A series of phenylglycine derivatives were prepared from D-Phenylglycine,D-2-chlorophenylglycine, D-4-chlorophenylglycine and D-4-nitrophenyl-glycine. Thesederivatives were bonded to3-aminopropyl silica to afford new Pirkle-type CSPs. Theenantioseparation ability of the CSP derived from3,5-dimethylbenzoyl-D-phenylglycinewas evaluated. The result showed that, in the reversed-phase consisting of acetonitrile andwater, the enantioseparation ability was better than in other mobile phases.