| Gastrodin is one of the bioactive constituents isolated from Gastrodia elata Blume and has been known as the anti-convulsant,anxiolytic,and analgesic effect.Iridoid glycosides are high polarity medicinal substances with antineoplastic,antiallergic,antioxidant,antiviral,hyperglycemic,and other pharmacological properties.Gastrodin and iridoid glycosides are the main active constituents in traditional Chinese medicines,which have been used as a quality control standard for original herbs and herbal preparations.Traditional Chinese medicines are complex biological samples with complex sample matrix and disruptive,which are very difficult to isolate and purify.Moreover,iridoid glycosides with similar structure are low content in traditional Chinese medicines.At present,it needs to be established a targeted purification technology to adapt the needs of medicinal materials quality control and pharmacological activity research.In this research,we studied the selective pre-concentration of gastrodin and iridoid glycosides using hydrophilic molecularly imprinted polymer.Because of excellent selectivity,high capacity,and good affinity,molecularly imprinted polymers were applied as solid-phase extraction adsorption material.The molecularly imprinted solid phase extraction(MISPE)method was established for the sample pretreatment of glycosidic substance.The paper mainly consisted of three parts as follows:In chapter one,gastrodin and iridoid glycosides are introduced,including their physiological activity and analysis method.In addition,molecular imprinting technology is also reviewed.In chapter two,superhydrophilic molecularly imprinted polymers(MIPs)were developed to specifically recognize gastrodin.Polymers were synthesized via the bulk polymerization in aqueous solution using alkenyl glycosides glucose(AGG)as a novel water-miscible functional monomer.The non-imprinted polymers(NIPs)have been also prepared using the same method but without the template.The photographs of the contact angles and the dispersion properties confirmed that polymers displayed excellent superhydrophilicity.Adsorption experiments showed that polymers exhibited high selectivity.Based on superhydrophilic molecularly imprinted polymers,a MISPE method was established and a variety of parameters affecting MISPE was optimized.Under the optimized conditions,the wide linear range was 0.001-100.0 ?g / m L.Low limits of detection(LOD)and quantification(LOQ)are 0.3 ?g / mL and 0.9 ?g / mL,respectively.The method showed higher recoveries(90.5 %-97.6 %)with RSD < 6.4 %.These results demonstrated one efficient,highly selective and environmentally-friendly MISPE technique,which was used for the pre-concentration of gastrodin from an aqueous extract of Gastrodia elata roots,was devoleped.In chapter three,hydrophilic magnetic molecularly imprinted polymers(MMIPs)have been prepared by directly coating onto Fe3O4,using AGG as the water-soluble functional monomer,which introduces abundance of hydrophilic groups into polymers.Photographs of the water contact angles and dispersion properties demonstrated that MMIPs had excellent hydrophilicity.MMIPs were characterized by Fourier transform infrared spectroscopy,vibrating sample magnetometry,transmission electron microscopy,scanning electron microscopy,and X-ray diffraction.Adsorption experiments indicated that MMIPs had the high selectivity and excellent imprinting effect.Under the optimized hydrophilic magnetic molecular imprinted solid phase extraction(MMISPE)conditions,a wide linear range(0.05-50.0 ?g / mL)with LOD(0.005-0.01 ?g / mL)and LOQ(0.019-0.033 ?g / mL)was achieved.The method showed excellent recoveries(87.6-98.8 %)and precision(RSD < 6.1 %).The chromatograms obtained by MMISPE showed that eight iridoid glycosides in Zhi-Zi-Jin-Hua pills were selectively enriched and matrix interference was minimized.These results suggested that the developed MMISPE-HPLC method could be used for the determination of iridoid glycosides in the herbal preparations. |
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