亲水性磁性表面分子印迹聚合物的构建及其定向分离迷迭香酸的研究

Magnetic surface molecularly imprinted polymers (MMIPs) have the advantages of molecular imprinting specificity and rapidity of magnetic assisted separation, which have broad application prospects in the field of separation and purification of forest plant active components. However, MMIPs exhibited low specificity or selectivity when it was applied in purification of water-soluble natural products from aqueous systems. In order to overcome these problems, a hydrophilic and high recognition properties MMIPs were constructed through surface molecular imprinting technology (SMIT), and applied in separation and purification of rosmarinic acid from Perilla seed flour subcritical water extracts. Firstly, hydrophilic and high recognition properties surface molecularly imprinted polymers (SMIPs) were prepared by surface grafting copolymerization method on the functionalized silica gel modified with β-cyclodextrin. Then, the magnetic ferroferric oxide nanoparticles were employed as the substrate materials and then encapsulated by SiO2. Subsequently, the magnetic Fe3O4@SiO2 was functionalized by β-cyclodextrin which was chemically bonded on their surfaces, and the magnetic nano-molecular imprinted polymers were fabricated. The structural characterization, adsorption properties and adsorption mechanism of the resulting molecularly imprinted polymers were analyzed. Finally, combined with solid phase extraction, the molecularly imprinted polymers will be applied in the separation and purification of rosmarinic acid from the subcritical water extracts of Perilla seed flour. The rosmarinic acid could be quickly separated from the sample under the action of additional magnetic field. The project could not only provide a green purification technology for the efficient separation of rosmarinic acid from perilla seed flour, but also develop a method for hydrophilic MMIPs to promote the efficient extraction and utilization of forest plant active components.

磁性表面分子印迹聚合物（MMIPs）兼具分子印迹的特异性和磁辅助分离的快捷性，在林源植物活性成分的分离纯化领域具有广阔的应用前景。但是，采用MMIPs从水相系统中富集水溶性天然活性产物时存在特异性偏低的问题。本项目拟构建一种亲水性的MMIPs材料，应用于紫苏粕亚临界水提物中迷迭香酸的富集和纯化。首先，在硅胶基质的表面键合β-环糊精，制得在水相中具有较高识别性能的表面分子印迹聚合物(SMIPs)；然后，在磁性四氧化三铁基体外层包裹SiO2后键合β-环糊精获得MMIPs，对制备的MMIPs进行结构表征以及吸附性能和吸附机理分析；最后，结合固相萃取和磁分离技术实现紫苏粕亚临界水提取液中迷迭香酸的高效快速分离。本项目的实施不仅可以提供一种从紫苏粕中高效分离迷迭香酸的绿色纯化技术，还将示范一种构建亲水性MMIPs的方法，从而促进林源植物中活性成分的高效提取和利用。

迷迭香酸是一种优良的天然抗氧化剂，已广泛应用于制药、食品、化妆品等领域。紫苏籽粕中含有大量的迷迭香酸，是一种价格低廉、资源丰富、有潜力的迷迭香酸提取原料。磁性分子印迹聚合物因兼具分子印迹的特异性和磁辅助分离的快捷性，在植物活性成分的分离纯化领域具有广阔的应用前景。但是，采用磁性分子印迹聚合物从水相体系中富集水溶性天然活性成分时存在特异性偏低的问题。为了提高紫苏籽粕提取物中迷迭香酸的分离纯化效率，本项目构建了一种亲水性的磁性分子印迹聚合物材料，应用于紫苏籽粕亚临界水提物中迷迭香酸的富集和纯化，实现了对迷迭香酸的特异性吸附和分离。在本项目中，首先以磁性Fe3O4纳米颗粒为载体，在Fe3O4纳米颗粒外层键合3-丙基三甲氧基硅烷后，以迷迭香酸为模板分子，以4-乙烯基吡啶为功能单体，二甲基丙烯酸乙二醇酯为交联剂，偶氮二异丁腈为引发剂，制备得到了迷迭香酸的亲水性的磁性分子印迹聚合物。然后，对制备的迷迭香酸磁性分子印迹聚合物的形貌特征、比表面积和接触角等进行表征，并对其吸附性能进行考察。结果表明，制备的分子印迹聚合物具有均匀的球形结构、比表面积大且亲水性良好；对迷迭香酸具有特异吸附性，在迷迭香酸标准溶液中3h达到最大吸附量(8.60mg/g)，且能够实现从紫苏籽粕亚临界水提物中分离迷迭香酸，吸附量为5.75mg/g。上述研究结果，将为植物活性物质的分离纯化及磁性分子印迹技术的应用提供新的思路与理论基础。