New process for preparing Ginkgo biloba leaf extract for treatment of cerebral and peripheral vascular disorders, neurodegenerative disorders, and proliferative disorders

摘要

Preparing an extract from leaves of Ginkgo biloba containing at least 50 % flavone-glycosides and 12 % terpene-lactones. Preparing an extract from leaves of Ginkgo biloba containing at least 50 % flavone-glycosides and 12 % terpene-lactones comprising the following steps: (1) extracting the dry powdered leaves with ethanol containing at most 20% by weight of water; (2) concentrating the extract under reduced pressure in the presence of aqueous sodium chloride and eliminating the dark oil from the remainder of the clear solution; (3) washing the solution by liquid-liquid extraction using n-hexane, n-heptane or cyclohexane; (4) liquid-liquid extraction of the aqueous phase with ethyl acetate; and (5) washing the ethyl acetate extract sodium chloride solution and evaporation.