手性温敏凝胶P（NIPAM-co-NALL）的制备及识别性能

摘要

A series of novel thermo-sensitive hydrogels based on N-isopropylacrylamide( NIPAM) containing L-leucine groups was designed and synthesized for chiral recognition. L-Leucine used as chiral pool, the chiral monomer N-acryloyl-L-leucine methyl ester( NALL) was obtained by sterifization with methanol to protect car-boxyl group and then condensation with acryloyl chloride in the presence of trirthylamine in N,N-dimethylfo-mamid( DMF) and gave the chiral monomers N-acryloyl-L-leucine methyl ester( NALL) , whose structure was characterized by infrared( IR) and proton nuclear magnetic resonance ( 1 H NMR) . Then the subsequent co-polymerization was carried on between NALL as chiral recognition units, NIPAM and N,N’-methylenebisacry-lamide( MBAA) as linkage agent in the presence of azobisisobutyronitrile ( AIBN ) in ethanol with different mass ratios. The P(NIPAM-co-NALL) hydrogels were identified by IR. The swelling behavior, deswelling and reswelling kinetics of the chiral hydrogels were studied, and the results showed that all the P( NIPAM-co-NALL) hydrogels exhibited evident temperature-sensitivity. Due to the hydrophobicity of NALL incorporated into the structure of the chiral gels, the thermo-sensitivity of the chiral gels was lower than that of PNIPAM gel. The chiral selective adsorption and chiral recognition performance were also investigated by D, L-phenyl-alanine(D, L-Phe) as model drugs. The results indicated that compared with PNIPAM gel, the chiral gels performed higher adsorption rate and larger adsorption quantities for D-Phe enantiomers. Increasing the con-tents of chiral monomer or the controlling temperature would improve the chiral recognizable capacity and effi-ciency of resolution. Furthermore, P ( NIPAM-co-NALL ) hydrogels could be reused, which remained the chiral recognition property after three-times reuse although the absorption capacity decreased to 27.6% of the original.%以L-亮氨酸( L-Leu)为手性源,经酯化和缩合等步骤制备手性单体( NALL),以该单体为手性识别基团,在交联剂N,N'-亚甲基双丙烯酰胺和引发剂偶氮二异丁腈的作用下,与N-异丙基丙烯酰胺( NIPAM)以不同的质量比发生自由基共聚,制备了一系列新型手性温敏水凝胶P( NIPAM-co-NALL),其结构经红外光谱确证.相比于PNIPAM 水凝胶,疏水性单体 NALL 的引入使 P ( NIPAM-co-NALL )凝胶的温敏性下降.以D, L-苯丙氨酸为模型药物对P( NIPAM-co-NALL)凝胶的手性识别和拆分性能进行研究,结果表明,手性温敏凝胶对D型对映体具有选择吸附性,且吸附量随着手性单体含量的增加而增加；提高温度(40℃)有利于手性温敏凝胶对D, L-苯丙氨酸的手性识别和拆分. P( NIPAM-co-NALL)凝胶在重复使用后依然具有手性识别性能,但其吸附量随着使用次数的增加而下降,3次重复使用后吸附量下降到原来的27.6%.