Purificatioon Of Ginkgo Biloba Flavonoids By Ultrafiltration Membrane And Application Of Molecular Imprinting Technique

Ginkgo is a tree species with great value.Ginkgo biloba flavonoids is the main ingredients which has the medicinal value. It has been widely used in medicine and chemical field. The purification technology also has great development. Membrane technology and molecular imprinting technique have the advantages by high efficiency and energy saving. For this, there are researched and promotion.In this paper, ultrafiltration was applied to purify GBE crude product in attempt to replace the traditional methods, save ethanol, reduce energy consumption and enhance utilization rate of resources. Firstly, based on the molecular weight cut-off (MWCO)of membrane and the molecular weight of active component, certain membranes were adopted. According to previous water flux test, four membranes (PVDF100KD, PAN50, PES10KD, PES6KD)were selected for further study. The operating parameters on membrane separation efficiency of Ginkgo Flavonoids consist of operating temperature, filtration pressure, feed concentration and runtime. These parameters were optimized by single-factor or orthogonal experiment. The polyethersulfone membrane with a MWCO of10000had the best effect on purification of flavonoids from Ginkgo Bilola Extract. The content of flavonoids from Ginkgo Bilola Extract is24%before ultrafiltration. It can be elevated to68%with the applicatiion of membrane technology. Scanning electron microscope (SEM) and Fourier Transform infrared spectroscopy (FTIR) are used to anlyze membrane fouling.Imprinting molecule synthesis used precipitation polymerization. In the synthesis process, three conditions, such as functional monomer, reactant ratio and porogen, had effects on it. These were investigated. Afterwards, the synthesized polymer, kaempferol-MIP, was analyzed by SEM. The optimum conditions were as follows:2-vinyl pyridine (2-VP) as the functional monomer, Ethylene glycol dimethacrylate (EDMA) as the cross-linker, reactant ratio n(KAE)∶n(2-VP)∶n(EDMA)=1∶5∶25, in the porogens of acetonitrile. The polymerizations were reacted at60℃for24h. We can get molecularly imprinted micro-spheres, which size was about0.25μm. The paper also examined the bilateral coupled effect within film and film, film and the imprinting molecule. First, the solvents was ultrafiltration by PAN50KD-PES10KD. Then, the filtrate absorbed by the2-VP MIP. It can purificate flavonoids further to98%.In conclusion, membrane separation technology and molecular imprinting technique were simple and efficient method. The coupling of them also has these advantages. These processes can used to isolate and purify flavonoids from Ginkgo Bilola Extract.