Study on Extraction of Total Flavonoids from Ginkgo Biloba Leaves by Reflux Method

Total flavonoids were extracted from Ginkgo biloba leaves by ethanol using refulx method.The effects of solid-liquid ratio ethanol volume fraction,extraction time and extraction temperature on total flavonoids extraction rate were explored by single factor experiment and orthogonal experiment.The optimal extraction conditions were determined as follows:solid-liquid ratio of 1∶45(g∶mL),ethanol volume fraction of 50%,extraction time of 2.0h,extraction temperature of 70℃,under which total flavonoids extraction rate was up to 0.918%.Furthermore,the microwave-assisted extraction was carried out.It was found that by microwaveassisted intermittent extraction with power of 640 W,time of 15×10s,the total flavonoids extraction rate reached 0.91%,approaching that obtained by traditional extraction for 3h.