Method for preparing an extract of ginkgo biloba leaves highly enriched in active ingredients

摘要

A method for preparing an extract of Ginkgo biloba leaves is described, comprising the following successive steps: i) extracting dried fragments of Ginkgo biloba leaves in ethanol containing at least 20 wt% of water; ii) concentrating the extract under reduced pressure in the presence of at least an aqueous sodium chloride solution and eliminating the dark oil from the rest of the clear solution; iii) washing the residual aqueous solution by liquid-liquid extraction with either nûhexane, n-heptane or cyclohexane; iv) liquid-liquid extraction of the washed aqueous phase with ethyl acetate; v) washing the ethyl acetate phase obtained at step iv) with a sodium chloride solution then evaporating by dry process the washed ethyl acetate phase.