| 摘要 |
FIELD: natural compounds. ^ SUBSTANCE: invention relates to a method for isolating betulin representing a pentacyclic triterpenoid of lupan series from the white-stem birch bark. Method involves extraction of birch bark with methyl-tert.-butyl ester, the following treatment of extract with alkali solution and recrystallization of the prepared product from ethyl acetate. The yield of betulin is 15% (as measured for birch bark dry weight) with purity above 95%. Method allows exclusion of labor-consuming and expensive chromatography methods for purifying betulin. Invention can be used in chemistry, medicine and pharmacy. ^ EFFECT: improved preparing method. ^ 2 cl, 2 ex |
