Patent ID: 6174531
Filing Date: 2001-01-16
Classification: A61K,A61P

Abstract:
A process for the production of an extract of improved biological property from the leaves of Ginkgo biloba comprising:(a) collecting green Ginkgo biloba leaves of a desirable quality;(b) treating the leaves with a 50% aqueous alcohol solution to obtain a crude extract;(c) filtering and concentrating the crude extract to a high density fluid extract;(d) diluting the high density fluid extract with boiling water to remove water-insoluble lipophilic compounds;(e) eluting the resultant extract through a chromatographic column with a gradient of aqueous alcohol to obtain a plurality of fractions containing flavone glycosides and a plurality of fractions containing lactones and to remove alkyl phenolic compounds;(f) combining a suitable number of the fractions containing flavone glycosides with fractions containing lactones to obtain a refined extract having a weight ratio between the flavone glycosides and the lactones of 24 to 6, about 27 to about 6-7, 27 to 7, or 30 to 7; and optionally(g) further treating the refined extract with a non-polar solvent to remove alkyl phenols.