| 摘要 |
A process for extracting physiological active materials (I) from ginko tree leaves (II) comprises (a) extracting (I) with the mixt. soln. of lower alcohol and lower acetic acid or lower ketone from (II), (b) dissolving the residues to aq. lower alcohol or aq. lower ketone, (c) adjusting the extracted soln. with acid to pH 4 and filtering the produced precipitate, (d) adjusting again the extracted soln to pH 6-8, (e) dissolving the residues to ethyl alcohol and (f) concentrating the dissolved soln.
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