Process for the Extraction of Flavones from Ginkgo Leaves

Process for the extraction of flavones from Ginkgo leaves with ethanol-water was studied,and content of flavones was determined by spectrophotometry.The optimal condition was chosen by orthogonal tests as extraction with 70% ethanol at 70 oC,ratio of solid to liquid 1: 20 and at pH 8,and the extraction rate of flavones reach 92.2%.