Modified Preparation And Molecular Imprinting Purification Research Of The Active Ingredient From Ampelopsis Grossedentata

Abstract:In this paper, for the low content of myricetin in natural plant extracts and difficult of extraction and purification, metasulfite dehydrogenation oxidation technology was adopted to achieve the effective preparation of myricetin, and molecular imprinting solid-phase extraction technology was employed to accomplish the separation and purification of myricetin from the complex system, which laid a foundation for the further development and utilization of pharmacological effects of myricetin.First, the efficient conversion process of dihydromyricetin to myricetin from Ampelopsis grossedentata extracts was achieved by metasulfite dehydrogenation oxidation technology. The HPLC, IR, elemental analysis and nuclear magnetic resonance hydrogen spectrum were used for the qualitative and quantitative analysis of dehydrogenation products. The results show that the main composition in the dehydrogenation products was myricetin, and the content of myricetin increased from2.38%to85.57%, the yield reached20.27%.Second, the synthetic azobenzene-containing complex was chemically bonded onto the surface of activated silica particles. Myricetin molecularly imprinted polymer microspheres were subsequently prepared through surface imprinting polymerization using myricetin, EGDMA, AIBN as the template, crosslinker and initiator respectively. The IR and SEM results demonstrate that the polymerization has occurred on the surface of the grafting silica, and the resulting microspheres have the regular shape, and the diameters are approximately9μm.Third, static and dynamic adsorption experiments were done to study the adsorption properties of MIPs. The results show that the preparation MIPs have rapid adsorption kinetics, and about120min to reach adsorption equilibrium. Compared with the same kind of molecularly imprinted materials, its adsorption capacity is larger, reaching7mg·g-1Finally, the MIP-SPE column was prepared by using MIPs as solid phase extraction adsorbents. Then, the selective adsorption performance of the MIP-SPE column was studied, and applied it to the dehydrogenation mixture for separation and enrichment of myricetin. The experimental results suggest that the MIP-SPE column exhibits highly specific molecular recognition for myricetin, and has the low adsorption retention ability for the structure analogue dihydromyricetin. The enrichment factor for myricetin is twice as much as that for dihydromyricetin, and the recovery for myricetin can reach97.2%. In the application of the dehydrogenation product, the MIP-SPE column realized the effective separation and enrichment of myricetin from the complex system, which laid the foundation for molecular imprinting materials in the application of natural flavonoids products.