Patent DE-102006019863-A1 (DE)
Title: 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
Inventor: OSCHMANN RAINER
IPC: A61K36/16
Filed: 2006-04-28
Abstract: 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 salt; (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.