The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 2012
Filed:
Jan. 09, 2008
Jan Sarek, Horni Mecholupy, CZ;
Michal Svoboda, Prague, CZ;
Marian Hajduch, Moravsky Beroun, CZ;
Univerzita Karlova V Praze, Prirodovedecka Fakulta, Olomouc, CZ;
Univerzita Palackeho V Olomouci and I.Q.A., a.s., Praha, CZ;
Abstract
The invention relates to a method of preparation and isolation of betulin diacetate from birch bark from paper mills and its optional processing to betulin, wherein the birch bark is ground, mixed with two- to twenty-fold excess volume of water and is stirred so that all birch bark is dipped, then the fraction of the birch bark which floats on the surface is collected, said collected fraction is dried at the temperature in the range of from 50 to 85° C. and the betulin contained in the dried birch bark is then subjected to an acetylation reaction, after the acetylation the birch bark is dried at the temperature of from 50 to 100° C. and the formed betulin diacetate is then isolated from the birch bark by supercritical extraction of the birch bark with carbon dioxide at the pressure of 28-35 MPa and the temperature of from 50 to 100° C. and subsequently, the supercritical extract is recrystallized for direct use or for further processing. The further processing can be basic hydrolysis of the re-crystallized betulin diacetate to betulin.