混杂型多聚糖类手性固定相的制备及手性分离性能

Preparation and Enantioseparation Performance of Mixed-Type Polysaccharide-Based Chiral Stationary Phases

运用“一锅法”合成直链淀粉-三(苯基氨基甲酸酯)(A1)、纤维素-三(苯基氨基甲酸酯)(C1)和纤维素-三(3,5-二甲基苯基氨基甲酸酯)(C2)衍生物。用1H-NMR对衍生物的分子结构进行定量表征,确定其结构规整,取代完全。分别将所合成直链淀粉衍生物与纤维素衍生物以两种不同混合方式涂覆到大孔硅胶上制备混杂型手性固定相,并应用高效液相色谱法(HPLC)评价其对10种手性化合物的手性分离性能。与传统单一型手性固定相相比,所制备的混杂型手性固定相对于一些对映体表现出更优异的分离效能。

Amylose tris(phenylcarbamate)(A1),cellulose tris(phenylcarbamate)(C1)and cellulose tris(3,5-dimethyl phenylcarbamate)(C2)were synthesized by“one-pot”method.The structures of the derivatives were quantitatively characterized by 1H-NMR.The regular structure and complete substitution of the derivatives were confirmed.The obtained amylose and cellulose derivatives were then coated on the macroporous silica gel,giving rise to mixed-type chiral stationary phases(CSPs)by two mixing ways.Their enantioseparation abilities for ten chiral compounds were evaluated by HPLC.The chiral recognition abilities of the obtained mixed-type CSPs were compared with those of several single polysaccharide-based CSPs(commercialized coated-type CSP derived from C2),including A1,C1 and Chiralcel OD.The results showed that the mixed-type CSPs,especially those mixing with A1 and C2,exhibited higher enantioseparation performance for some chiral compounds,which could be ascribed to the combined enantioseparation abilities derived from the cellulose and amylose derivatives with different higher order structures in the mixed-type CSPs.The mixing methods,either before or after coating process,had no remarkable influences on the chiral recognition ability of the obtained CSPs.However,some mixed-type CSPs showed decreased enantioseparation abilities for a few chiral compounds,which have opposite elution orders on the two single CSPs.This work suggests that the mixed CSPs is probably more efficient for the improvement on the chiral recognition abilities in case both single CSPs follow the similar recognition mechanism.