碎片印迹聚合物的制备及其对薯蓣皂苷的分子识别

Preparation of a Molecular Fragment-imprinted Polymer and Its Molecular Recognition Capacity Toward Dioscin

针对分子印迹萃取及分离分析中的模板泄漏,采用碎片印迹技术制备适用于纯化薯蓣皂苷的分子印迹材料。以葡萄糖及齐墩果酸为模板碎片,4-乙烯基吡啶-N-异丙基丙烯酰胺为共同功能单体,采用沉淀聚合法制备出碎片印迹微球GL-OL-MIP4。当葡萄糖和齐墩果酸分别为0.6和0.1 mmol时,所得GL-OL-MIP4的分布系数高达368.2 mL·g^(-1),饱和吸附量约34.67 mg·g^(-1)。用红外光谱及扫描电镜表征GL-OL-MIP4的表面化学基团及形貌学特征,采用吸附法研究印迹材料的选择吸附能力,通过固相萃取研究其在分离纯化中的应用效能。Scatchard分析表明印迹材料GL-OL-MIP4主要有两类亲和位点,对薯蓣皂苷具有一定的选择吸附能力,以其为吸附剂固相萃取分离盾叶薯蓣中的薯蓣皂苷时,总回收率达99.66%,且产品中杂质大幅减少,目标物可得到较好的分离和纯化。这种印迹聚合物可重复使用10次,未见性能明显下降。

Aiming at solving the template leakage in the extraction and separation analysis by the molecular imprinted technique,a molecularly imprinted polymer was prepared by the fragment imprinted technique for the purification of dioscin.With glucose and oleanolic acid as the template pieces,and 4-vinyl pyridine-N-isopropyl acrylamide as the common functional monomer,a fragment-imprinted microsphere GL-OL-MIP4 was prepared by the precipitation polymerization method.When glucose and oleanolic acid were 0.6 and 0.1 mmol,respectively,the obtained molecularly imprinted polymer GL-OL-MIP4 possessed the maximum distribution coefficient,with a value of 368.2 mL·g^(-1) and a saturated adsorption amount of 34.67 mg·g^(-1).FT-IR and SEM were used to characterize the surface functional groups and topography characteristics of the polymer GL-OL-MIP4.The adsorption method was used to study on the selective adsorption ability of the molecularly imprinted materials.Additionally,the applicapability for the solid phase extraction with the molecularly imprinted polymers as the adsorbents was tested.The Scatchard analysis shows that the imprinted material GL-OL-MIP4 has two main kinds of affinity types,of which high affinity sites are responsible for the selective adsorption capacity of this imprinted material.When using the molecularly imprinted polymer as the adsorbent for the solid phase extraction from the crude extract of Dioscorea zingiberensis,dioscin can be effectively enriched and separated,with a recovery of 99.66%.Especially,the obtained product by this method contains less impurities and possesses higher purity.This molecularly imprinted polymer can be repeatedly used 10 times with no loss in the adsorption capacity.