Patent ID: 8865935

Claim:
A method of purifying betulonic acid, comprising the steps of: a) injecting a Jones oxidation reagent (CrO 3 /c-H 2 SO 4 /H 2 O) into a mixed solution of acetone and betulin to obtain an organic synthesis reaction product and filtering and concentrating the obtained reaction product; b) introducing ethyl acetate into the concentrated reaction product to liquid-liquid extract betulonic acid c) introducing a saturated aqueous sodium chloride solution (brine) into the ethyl acetate solution, in which the extracted betulonic acid is dissolved, to wash the ethyl acetate solution and remove impurities therefrom; d) introducing hexane or petroleum ether, as a nonpolar solvent, into the ethyl acetate solution to remove nonpolar substances, passing the washed ethyl acetate solution through an adsorption tower filled with aluminum oxide or silica gel, as a polar adsorbent, to remove polar substances, and then drying the ethyl acetate solution to produce betulonic acid (purity: more than 92%, yield to birch bark: 2.75 wt %); and e) dissolving the produced betulonic acid in a mixed solvent of ethanol and acetonitrile, separating and treating the mixed solution using a semi-preparative chromatography column filled with C 18 stationary phase, and then drying the separated and treated mixed solution to produce high-purity betulonic acid (purity: more than 99.5%, yield to birch bark: 1.8 wt %).