分子印迹聚合物选择性富集长春碱的研究

Synthesis of molecularly imprinted polymers for the application of selective clean-up vinblastine from Catharanthus roseus extract

分子印迹聚合物(MIPs)是近年来发展起来的一种对特定分子(模板分子)具有高度选择性的合成高分子材料.本文以长春碱(VLB)为模板分子,以甲基丙烯酸(MAA)为功能单体、乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,在偶氮二异丁腈(AIBN)的引发下制备了长春碱印迹聚合物(VLB-MIP).采用紫外光谱对VLB与MAA之间形成的模板-功能单体复合物进行了分析,通过扫描电镜(SEM)对制备的VLB-MIP的表面形态进行了表征,并用BET法对MIP表面的孔径进行了测定.结果表明,VLB-MIP与未加模板分子制备的非印迹聚合物(NIP)相比表面多孔、粗糙,比表面积显著增加.以VLB-MIP作为固相萃取(SPE)的吸附剂,对VLB-MIP的选择性进行了评价,VLB-MIP能特异性地吸附VLB,而对VLB的结构类似物长春新碱(VCR)却没有表现出明显的吸附行为.将长春花提取物上样于填充VLB-MIP的SPE柱上,在最优实验条件下,长春花提取物中的VLB能被高效富集.此外,上样溶剂对MIP柱的吸附容量有影响,长春花提取物溶于非极性溶剂甲苯时,MIP的吸附容量最大为750μg/g,其次是氯仿吸附容量为625μg/g,最小的是甲醇为250μg/g.

Molecularly imprinted polymers（MIPs） are synthetic tailor-made polymers with high selectivity towards a particular substance（template）.A MIP using vinblastine（VLB） as the template molecule was synthesized and characterized.The presence of monomer-template complexes in a non-covalent way was confirmed by UV-vis spectrometry analysis.The polymerization was performed using methacrylic acid（MAA） as functional monomer,ethylene glycol dimethacrylate（EGDMA） as cross-linking agent,and toluene as porogenic solvent by a thermo-polymerization method.The characterization of the obtained MIP was evaluated by scanning electron microscope（SEM） and Brunauer-Emmett-Teller（BET） analysis.It was observed that the morphology of the MIP was more porous and rough,and the surface area had a significant increase than that of non-imprinted polymer（NIP）.This MIP was used as the sorbents of（SPE） to assess the selectivity of the MIP after optimization of the SPE protocol.VLB was specifically adsorbed on the MIP cartridge,while to vincristine（VCR）,the chemical analogue of VLB,almost no selective binding appeared.On the basis of the results,Catharanthus roseus extract were applied to the MIP cartridge for investigating its capability to extract VLB from the plant extract,and the capacity of the MIP cartridge was also evaluated.It was shown that the MIP could effectively enrich VLB from C.roseus extract and the recovery amounted to 93.8%.Surprisingly,the solvents dissolving the samples had significant influence on the capacity of the MIP cartridge;it was 750 μg/g in toluene,625 μg/g in chloroform,and 250 μg/g in methanol,respectively.