Study on microwave extraction and purification of total flavonoids from ginkgo leaf

The optimum process of total flavonoids in Ginkgo biloba leaves by microwave extraction were determined by orthogonal design,the solvent concentration,solid-liquid ratio, extraction time and extraction times were studied to determine the effects on the extracting of total flavonoids,the optimum extraction conditions were ethanol concentration 60%,ratio of solid to liquid 1:70, extracting 2 times,3min every time,the rate was 2.061%. The total flavonoids in Ginkgo biloba leaves was further separated and purified by macroporous resin.The optimal conditions of resin purification were that using D101 type macroporous resin,80% ethanol as solvent,flow rate of elution was 2 times of column volume pre hour,and collecting alcohol eluent to 3 times of the column volume.After purification by resin,the content of total flavonoid was increased from 17.08% to 44.17%.