Li Zhaozhou, Qin Cuili, Li Daomin, Hou Yuze, Li Songbiao, Sun Junjie
College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
College of Food and Bioengineering, Henan University of Science and Technology, No. 263 Kaiyuan Avenue, Luolong District, Luoyang 471023, PR China.
J Pharm Biomed Anal. 2014 Sep;98:210-20. doi: 10.1016/j.jpba.2014.05.031. Epub 2014 May 29.
The molecularly imprinted polymers (MIPs) were prepared by an oxidation-reduction polymerization system using a non-covalent molecularly imprinting strategy with hypericin as the template, acrylamide as the functional monomer and pentaerythritol triacrylate as the cross-linker in the porogen of acetone. The UV spectrum revealed that a cooperative hydrogen-bonding complex between hypericin and acrylamide might be formed at the ratio of 1:6 in the prepolymerized system. Two classes of the binding sites were produced in the resulting hypericin-imprinted polymer with the dissociation constants of 16.61μgL(-1) and 69.35μgL(-1), and the affinity binding sites of 456.53μgg(-1) and 603.06μgg(-1), respectively. The synthesized MIPs were characterized by scanning electron microscope, thermogravimetric and differential thermal analysis. High-performance liquid chromatography was used to investigate the adsorption and recognition properties of the MIPs. Selective binding of the template molecule was demonstrated in comparison to the analog pseudohypericin. After the Hypericum perforatum L. plant being air dried and finely ground, an extract was prepared by shaking the powder in a methanol-water solution (80:20, v/v), vacuum filtration though a Büchner funnel, liquid-liquid extraction with ethyl ether and ethyl acetate, and evaporating on a rotary evaporator until dry. With the sorbents of the optimized MIPs, a molecularly imprinted solid-phase extraction (MISPE) procedure was developed for enrichment and separation of hypericin from the Hypericum extract in the presence of interfering substances. The selective extraction of hypericin from herbal medicine was achieved with the recovery of 82.30%. The results showed that MISPE can be a useful tool for specific isolation and effective clean-up of target compounds from natural products.
以金丝桃素为模板、丙烯酰胺为功能单体、季戊四醇三丙烯酸酯为交联剂，在丙酮致孔剂中采用氧化还原聚合体系通过非共价分子印迹策略制备了分子印迹聚合物（MIPs）。紫外光谱显示，在预聚合体系中，金丝桃素与丙烯酰胺可能以1:6的比例形成协同氢键复合物。所得金丝桃素印迹聚合物产生了两类结合位点，解离常数分别为16.61μgL(-1)和69.35μgL(-1)，亲和结合位点分别为456.53μgg(-1)和603.06μgg(-1)。通过扫描电子显微镜、热重和差热分析对合成的MIPs进行了表征。采用高效液相色谱法研究了MIPs的吸附和识别性能。与类似物假金丝桃素相比，证明了模板分子的选择性结合。将贯叶连翘植物风干并研磨成细粉，通过在甲醇-水溶液（80:20，v/v）中振荡粉末、通过布氏漏斗真空过滤、用乙醚和乙酸乙酯进行液-液萃取以及在旋转蒸发仪上蒸发至干来制备提取物。以优化后的MIPs为吸附剂，开发了一种分子印迹固相萃取（MISPE）方法，用于在存在干扰物质的情况下从贯叶连翘提取物中富集和分离金丝桃素。实现了从草药中选择性萃取金丝桃素，回收率为82.30%。结果表明，MISPE可作为从天然产物中特异性分离和有效净化目标化合物的有用工具。
