摘要 |
<p>The invention provides methods for separating outer birch bark from inner birch bark. The invention also provides methods for isolating betulin; lupeol; betulinic acid; 9,10-epoxy-18-hydroxyoctadecanoic acid; 9,10,18-trihydroxyoctadecanoic acid; polyphenolic polymers and fatty acids from birch bark.</p> |