沉淀聚合法制备葛根素印迹微球及其固相萃取葛根粉

Preparation of Puerarin-Imprinted Polymer Microspheres by Precipitation Polymerization Technique for Use in Solid Phase Extraction of Flavonoids from Pueraria Root Powder

以葛根素为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂沉淀聚合法制备葛根素印迹聚合物微球。用扫描电镜观察微球形貌,静态吸附法测试聚合物的吸附行为。探讨分子印迹聚合物(molecularly imprinted polymers,MIPs)对葛根粗提液中葛根素的吸附、解吸附及固相萃取效能。结果表明,优化的葛根素MIP3对纯模板的静态吸附量达37.9 mg/g;对粗提液中目标化合物的吸附率为(96.3±1.81)%,以水、甲醇-醋酸(9∶1,v/v)及50%甲醇溶液为洗脱剂的单次解吸率为27%~34%,用水从MIP3上解吸出的总溶液经脱除溶剂后,所获粗品葛根素含量最高,达(37.4±2.87)%。在优化条件下,通过MIP3固相萃取葛根粗提液,葛根素回收率达71.6%,产品纯度高于75%。

Puerarin-imprinted polymer microspheres(MIPM) were prepared by precipitation polymerization technique using puerarin, methacrylic acid(MAA) and ethylene glycol dimethylacrylate(EGDMA) as the template, functional monomer and cross-linker, respectively. Scanning electron microscope(SEM) was used for evaluating the morphology of polymer and a static method was used for characterizing the adsorption behavior. The application of the MIPM for adsorption, desorption and solid phase extraction of puerarin from crude pueraria root extract was explored. Results indicated that the adsorption capacity for the optimized MIPM(MIP3) toward the pure template reached 37.9 mg/g, with an adsorption percentage of(96.3 ± 1.81)% toward the target compound in the crude extract. The desorption percentage varied within the range of 27%–34% when water, methanol-acetic acid(9:1, v/v) and 50% aqueous methanol were used as the eluents, respectively. Furthermore, the product desorbed from the MIP3 using water as the eluent contained the highest content of puerarin(37.4 ± 2.87)%. Puerarin product with 75% purity can be obtained by MIP3 using single-step solid phase extraction with a puerarin recovery of 71.6%.