Preparation method and application of diketone compound dysosma versipellis biflavone A-E

The invention relates to a preparation method and application of a diketone compound dysosma versipellis biflavone A-E, which can effectively solve the problem of preparing the biflavone compound dysosma versipellis biflavone A-E from dysosma versipellis and realizing the application of the biflavone compound dysosma versipellis biflavone A-E in preparation of an anti-Alzheimer disease drug. The compound is separated from a dysosma versipellis medicinal material, the dysosma versipellis biflavone A-E has inhibitory activity on acetylcholin esterase, the application of the dysosma versipellis biflavone A-E in preparation of the anti-Alzheimer disease medicine is realized, the raw materials are rich, the preparation method is easy to operate, the dysosma versipellis biflavone A-E can be effectively used for preparing the anti-Alzheimer disease medicine, the new application of the dysosma versipellis medicinal material is developed, and the dysosma and the method has obvious economic and social benefits. 本发明涉及双酮