Extraction of Total Flavonoids from Ginkgo biloba by Decompressing Inner Ebullition

[Objective] To study the extraction method of total flavonoids from Ginkgo biloba.[Method] By using the decompressing inner ebullition,the Ginkgo biloba powder was desorbed and extracted to investigate the effects of each factor on the extraction rate,the best desorption and extraction conditions were found out,and then compared with that of traditional extraction method.[Result] The optimal desorption conditions were:80% ethanol as the desorption solvent,20 min desorption time and 15 ml solvent dose;the best extraction technology was 0.067 MPa extraction pressure,60 ℃ extraction temperature,30% ethanol as extraction solvent,twice of extraction,5 min each time;under these conditions,the extraction rate of flavonoids could reach up to 2.55%.Compared with the traditional ethanol extraction method,the temperature was cut down by 20 ℃,the extraction was eleven times faster,ethanol dose was two times less,the extraction solution had little pigment and impurities,and could be directly purified with macroporous adsorption resin,the purity of total flavonoids from Ginkgo biloba was 29.8%,the advantages were obvious.[Conclusion] The method is economical,rapid and efficient,therefore could be applied to the extraction of flavonoids from Ginkgo biloba.