Study On The Extraction And Separation Of Flavonoids From Herba Epimedii By Ultrahigh Pressure Extraction And Membrane Separation Technology

The ultra-high pressure extraction (UPE) also called ultrahigh isostatic hydrostatic pressure extraction is a new extraction technique. Studies have shown many advantages of UPE, such as less extraction time, high extraction yield, easy to purify, low power consumption and good biological activity. The membrane separation technology is based on the principle of pressure-driven to achieve the separation of solute and solvent, and has the functions of separation with different molecular weights. This technology works at room temperature and under low-pressure to achieve separation and concentration, and therefore it is low power consumption. Membrane as a filter medium is homogeneous continuum and made of polymer materials. Membrane separation technology is one kinds of physical filtration methods, so in the separation process it can not induce a qualitative change (ie, does not affect the molecular structure of materials). Extraction and purification of the effective ingredients from natural medicines by ultra-high pressure technology and membrane separation technology are important application directions in recent years.The traditional extraction methods of flavonoids from Herba Epimedii have many disadvantages such as complex procedure, long extraction time and low extraction yield. The pharmaceutical factories discovered that there was sedimentation in the new form injections of Herba Epimedii after a period of storage. This should owe to the macro-molecule impurities. So this paper did a deep research on the extraction and separation process of the total flavanods from Herba Epimedii with membrane separation technology, and could provide theoretical basis for the product development and application of Herba Epimedii extract.In this paper the main contents are as follow:1. It is the first time to extract flavonoids from Herba Epimedii with the UPE at room temperature. Based on the studies of the effects of pressure, solvent, ratio of solvent to feed material, extraction time and extraction times on the extraction yield of flavonoids, the optimized extraction factors were determined. Using the orthogonal test design, we got the optimum condition: extraction solvent is 50% ethanol; ratio of solvent(ml) to feed material(g) is 45; extraction duration is10s, extraction pressure is 300MPa. The results show that the process is stable and viable.2. The effects of different methods (UPE, reflux extraction, ultrasonic-assisted extraction and leaching extraction) on the extraction yield of flavonoids from Herba Epimedii were studied. The results indicate that the ultra-high pressure extraction has the highest extraction yields of flavonoids. And we observed that the extraction solution of UPE is the stablest and clearest within these four extraction methods and it is easy to be purified. It also shows that UPE has the selective characteristic because it can reduce the yields of protein, sugar, chlorophyll with the optimum extraction condition. At the same time, UPE only takes merely 3 minutes to complete entire process, which also improves the extraction efficiency of flavonoids.3. Using microfiltration, ultrafiltration, and nanofiltration to separate the total flavonoids of Herba Epimedii. Microfiltration was used to remove macro-molecule impurities, ultrafiltration was responsible for separating and concentrating the total flavonoids for sub-molecular. The optimum separation conditions of ultrafiltration membrane were T=25℃,P=0.1MPa,PH=7,t=1h,V=180n/min. The optimum purification and concentration conditions of nanofiltration membrane were T=25℃,P=7MPa,PH=7,t=1h,V=180n/min .The final yield of total flavonoids was 19.3% and the purity was 63.2%. The two indicators are lower than expected, which could provide a theoretical reference for the further separation and purification of total flavonoids of Herba Epimedii.4. After the membrane was used for a period of time, for the pollution of the microporous of the membrane surface, the membrane need for cleaning in order to maintain normal and stable flux. Because the materials, structural and process of membranes are different, the cleaning methods are also different. To ultrafiltration as an example: pressure washing, normal washing, reverse washing and chemical cleaning methods can be used. The membrane module can be filled with water. If the membrane was not used for a long period, it is necessary to reperfusion preservative (such as 1% formaldehyde). For reuse, make clean of preservatives and cleaning system with water repeatedly.