Preparing an extract comprises (a) extracting Ginkgo bilobaleaves with e.g. aqueous acetone； (b) separating major part of the organic solvent from the extract； (c) diluting the remaining concentrated aqueous solution with water； (d) adding ammonium sulfate to the remaining aqueous solution and extracting the formed solution with methylethylketone； (e) concentrating the obtained extract； (f) adding an aqueous solution of a lead salt to the obtained solution； and (g) extracting the remaining aqueous alcoholic solution with an aliphatic or cyclophatic solvent. Preparing an extract of Ginkgo bilobaleaves, comprises (a) extracting Ginkgo bilobaleaves at a temperature of approximately 40-100[deg] C, with aqueous acetone, 1-3C aqueous alcohol or anhydrous methanol； (b) separating major part of the organic solvent from the extract containing up to 10 wt.%, so that the water is added during final stages of distillation； (c) diluting the remaining concentrated aqueous solution with water to obtain a content of solid materials of 5-25 wt.%, allowing to cool by stirring, at a temperature of below25[deg] C, until to form a precipitate, where the resulting precipitate comprises lipophilic components, which does not dissolve well in water, and is separated； (d) adding ammonium sulfate to the remaining aqueous solution and extracting the formed solution with a methylethylketone or a mixture of methylethylketone and acetone； (e) concentrating the obtained extract to a solid material content of 50-70% and diluting the obtained concentrate diluted with water and ethanol to obtain a solution containing 50 wt.% of water and 50 wt.% of ethanol with a content of solid materials of 10 wt.%； (f) adding an aqueous solution of a lead salt to the obtained solution until a change in the brown color to amber color occurs, and separating the formed precipitate, in which a polyamide is used instead of a lead salt； (g) extracting the remaining aqueous alcoholic solution with an aliphatic or cycloph
