Method for obtaining an extract or Ginkgo biloba leaves
US4981688A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K2236/33
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The present invention relates to a novel method for obtaining an extract of Ginkgo biloba leaves. In the method according to the invention, the following successive operations are performed: grinding of the Ginkgo biloba leaves; extraction of the ground preparation of Ginkgo biloba leaves using an aqueous ketone solvent; concentration of the extraction liquors in order to precipitate the biflavonoids and the hydrophobic substances; filtration of the aqueous concentrate; alkalinization of the filtrate so as to precipitate the proanthocyanidins; removal by filtration of the insoluble fraction containing the proanthocyanidins; acidification of the filtrate; liquid-liquid extraction of the filtrate with a C.sub.4 -C.sub.6 ketone in the presence of ammonium sulfate; and recovery of the extract by taking the ketone phase to dryness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.