Extracting Ginkgo Biloba Flavonoids By Decompressing Inner Ebullition And Separation Technology

Using traditional technology to extract active subtences, Large amount of pigment can be dissolved out to bring down the clarity of the extraction solution due to the high content of pigment in the Leafs of Chinease herbs. Thus, a pretreatment such as water subsiding or extraction by petroleum ether was needed before the futher purification. Meanwhile, it brought some troubles to the following steps and caused the Loss of active subtences. For purpose of reducing the yield of pigment, selecting and optimizing a proper extaction technology becomes an important research direction.In this paper, the extraction and purification of the ginkgo biloba flavonoids were studied systematically. Decompressing inner ebullition (DIE) was chosed to extract ginkgo biloba flavonoids coupling with purification of adsorption with macroporous resinin, and the operation conditons were optimized. It was showed that DIE takes enormous advantages both on extraction and coupling with the following purification technology. The experiment results were as follows:(1) To extract ginkgo biloba flavonoids with DIE, small amount ethanol solution was used to immerse the raw material in order to desorb the flavonoids in Ginkgo biloba. Then30%ethanol solution with suitable temperature was added while the extraction pressure was decompressed rapidly to strengthen the extraction process by making the ethanol inside of the cell boil. The optimal conditions were as follows:the extraction pressure was0.067MPa, the extraction temperaure was60℃, the extraction time was5min. After being extracted for twice, the yield of ginkgo biloba flavonoids can reach2.55%under the optimal conditions above. Comparing with ethanol refluxing method, the temperature of DIE was brought down by20℃, the extraction rate was12times faster, the amount of ethanol consumption decreased to1/3times. Extracting with DIE, the dissolved amount of the impurites such as pigment decreases and the clarity of the extraction solution increased.(2) The extraction solution prepared by DIE can be purified directly by macroporous resin without other pretreatment process to decolor such as extraction with petroleum ether. Firstly, the macroporous resin with the type of HP-20was selected to be used for separation of ginkgo biloba flavonoids by the method of static adsorption. Then, the conditions were optimized by experiment of dynamic adsorption. After absorption purification, the purity of the ginkgo biloba flavonoids can reach29.8%, which was higher that of extraction with ethanol refluxing. It can decrease the amount of pigment in the extraction solution and prolong the service life for the macroporous resin to use DIE for extraction of ginkgo biloba flavonoids coupling with purification of adsorption with macroporous resin. Using DIE, the extraction efficiency and the quality of product was improved obviously on the basis of a high yiled for ginkgo biloba flavonoids.