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:
Oct. 15, 1991
Filed:
Sep. 29, 1989
Applicant:
Inventors:
Rex A Jennings, Holland, MI (US);
Jay F Stearns, Santa Rosa, CA (US);
Assignee:
Oclassen Pharmaceuticals, Inc., San Rafael, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549298 ;
Abstract
Podophyllotoxin is recovered from podophyllum resin with improved efficiency by adsorbing impurities out of a solution using a solid adsorbent, preferably alumina. This improvement finds application in an overall process for purifying podophyllotoxin from podophyllum resin in which the podophyllotoxin is first crystallized from the podophyllum resin, the crystals so formed are dissolved and subjected to the solid adsorbent treatment, crystals are then recovered and optionally recrystallized and dried to give the desired product.