Abstract: Novel dendritic displacers, Phe-D and Leu-D, with L-lysine as the dendritic branch and phenylalanine or leucine as the branching agent were synthesized by the solid-phase peptide coupling method on 1% cross-linked polystyrene bead functionalized with Fmoc-phenylalanine.The parameters in the steric-mass action (SMA) model for the novel displacers and their displacement performance were determined by chromatographic experiments, adsorption equilibrium and batch displacement experiments, and were compared with a typical displacer, N-α-benzoyl-L-arginine ethyl ester (BAEE）.Based on the SMA model parameters, affinity ranking plots of the displacers and proteins were obtained.The results showed that the dynamic affinities of the displacers reduced with an increase of the logarithm of the partition ratio of the displacer (lgΔ）.At a lgΔ less than 0.845, BAEE exhibited the highest dynamic affinity.At lgΔ from 0.845 to 3.08, Phe-D had the strongest dynamic affinity to the stationary phase.The batch displacement data for cytochrome C and α-chymotrypsinogen A demonstrated that the novel displacers gave a higher percentage of protein displacement from SP Sepharose HP due to more primary amine groups in the displacer molecules.On the other hand, the percentage of protein displacement increased by 70% due to the introduction of a phenyl group, confirming the enhancement effect of aromatic groups on protein displacement.

摘要： 高效置换剂的设计与合成一直是置换色谱发展的重要方向。采用固相合成方法合成了新型树枝状聚电解质置换剂Phe-D和Leu-D，并与置换剂BAEE进行了对比研究。研究结果显示，置换剂的动态亲和性随着lgΔ值增大而降低。在lgΔ<0.845时，BAEE具有最高的动态亲和力;而随着lgΔ进一步升高，Phe-D展现出最强的动态亲和力，这种趋势一直维持至lgΔ值达到3.08。蛋白质的静态置换实验表明，新型置换剂对蛋白质具有更高的置换百分率。这种高置换率主要源于置换剂中伯胺基团数量的增加;同时，Phe-D分子中苯基的引入使模型蛋白的置换百分率提高了70%，展示了苯基对蛋白质置换的促进作用。