According to insufficient data, the existing global standard Ginkgo biloba essence is EGb761 generated according to the German Schwabe trademarked procedure. Ginkgo biloba extract is a product extracted from the leaves of Ginkgo biloba L., as well as industrial essences are generally standard to include 24% flavonol glycosides and 6% ginkgo terpene lactones.
There are many techniques reported in the literature on the manufacturing process of Ginkgo biloba extract, mostly including acetone extraction-lead salt precipitation approach, ethanol extraction-macroporous resin adsorption separation approach, supercritical carbon dioxide extraction technique, alcohol extraction-extraction-chromatographic separation method, etc. The most commonly utilized technique in China is the ethanol extraction-resin separation method
The most extensively made use of technique in the house and abroad is natural solvent removal. Considering that other natural solvents are hazardous or volatile, ethanol is typically made use of as the removal agent. Experiments by Zhang Yonghong as well as others have actually revealed that the best conditions for drawing out flavonoids from ginkgo fallen leaves are 70% ethanol as the extraction remedy, the removal temperature is 90 ° C, the proportion of strong to fluid is 1:20, and the number of extractions is 3 times, each refluxing for 1.5 h.
1. Ethanol extraction-macroporous material adsorption separation technique
Pick out pollutants and also musty fallen leaves, laundry, chop, reflux with 70% ethanol to essence, separate the remove, filter, recoup ethanol under decreased pressure, high-speed centrifuge to get rid of slag, add proper amount of pure water to water down, add to macropore adsorption Resin column, eluted with water till the eluent is clear and light in color, then eluted with a certain focus of ethanol, gathered the eluate, focused under reduced stress, and dried in vacuum.
2. Acetone extraction-lead hydroxide precipitation technique.
Essence Pure Ginkgo Biloba with 60% acetone, filter after cooling down, remove the essence with carbon tetrachloride, add butanone and mix well, separate the acetone-butanone stage, include solid ammonium sulfate to the ketone phase and mix, filter For solid matter, vaporize the filtrate under decreased pressure to a concentration of 20%-60% of solid issue, as well as weaken with 50% denatured ethanol to a focus of 10% of solid issue. Include lead hydroxide suspension, and also filter off the precipitate. Focus the filtrate to half the quantity under reduced pressure, then include ammonium sulfate and butanone to the concentrated solution under stirring, and also precipitate the butanone-ethanol stage after the mixing is finished; different the butanone-ethanol stage from the water stage, and after that include it to the water stage Butanone was included in the mix, stirred, and also the butanone-ethanol stage was precipitated, which was incorporated into the above-mentioned butanone-ethanol stage. Add ammonium sulfate under mixing, divide the precipitated water stage after blending, completely dry the butanone-ethanol stage with sodium sulfate, evaporate to dryness under reduced pressure, liquify the denatured as well as viscous raffinate with denatured ethanol, and also area it for 12 hours to separate the precipitated precipitate. Evaporate under pressure and dry in vacuum.