Preparation of Ginkgo biloba extract used for treating e.g. dementia or cerebral disorder, involves extracting aqueous alcoholic solution of Ginkgo biloba leaves with heptane to remove alkyl phenol compounds

摘要

Extract of Ginkgo biloba is prepared by extracting Ginkgo biloba leaves at 40-100[deg]C with e.g. aqueous acetone, separating solvent, diluting concentrated solution with water, cooling, removing resulting precipitate, extracting solution with methyl ethyl ketone and/or acetone, concentrating, diluting, filtering, adding lead salt solution, extracting aqueous alcoholic solution with heptane to remove alkylphenol compounds, drying, adding ethanol, filtering and drying. Preparation of an extract from Ginkgo biloba having a reduced polycyclic aromatic hydrocarbons content, involves: (a) extracting fresh or dried green leaves of Ginkgo biloba (drug) at 40-100[deg]C using aqueous acetone, an aqueous 1-3C alkanol or anhydrous methanol; (b) separating the organic solvent from the extract to a maximum content of 2 wt.%, where water may be added during the final distillation steps; (c) diluting the remaining concentrated aqueous solution with water to a solid content of 5-25 wt.%, cooling under agitation to below 6[deg]C, allowing to stand for at least 1 hour at this temperature and removing the resulting precipitate comprising lipophilic components which are not completely soluble in water; (d) adding ammonium sulfate to the remaining aqueous solution and extracting the solution formed with methyl ethyl ketone and/or acetone; (e) concentrating the obtained extract to a solid content of 50-70 wt.% and diluting the obtained concentrate with water and ethanol such that a solution containing water (50 wt.%) and ethanol (50 wt.%) at a solids content of 10 wt.% is obtained, filtration is carried out and filtrate is further processed in step (f); (f) adding an aqueous solution of a lead salt to the solution thus obtained until a change in color from brown to amber occurs, and removing the precipitate formed, or using a polyamide instead of the lead sa (g) extracting the remaining aqueous alcoholic solution with heptane in order to further remove the alkylphenol compounds; (h) concentrating the remaining aqueous alcoholic solution under reduced pressure to an ethanol content of 5 wt.% and added with ammonium sulfate (20 wt.%); (i) extracting the solution obtained with a mixture of methyl ethyl ketone and ethanol in a ratio of 8:2-5:5 (weight/weight); (j) drying the resulting organic phase with ammonium sulfate (=20 wt.%) and concentrating to solid content of 50-70 wt.%, added with ethanol such that an ethanol content of at least 80 wt.% is obtained, maintained for at least 2 h at =12[deg]C and filtered; and (k) concentrating the resulting filtrate under reduced pressure at a maximum temperature of 60-80[deg]C and dried to obtain a dry extract having a water content of less than 5 wt.%. Independent claims are included for the following: (1) an extract obtained from Ginkgo biloba having a reduced polycyclic aromatic hydrocarbons content by the method; and (2) a medicament, food product or other preparation comprising the extract. ACTIVITY : Nootropic; Cerebroprotective; Cardiovascular-Gen. No biological data given. MECHANISM OF ACTION : None given.