Fremgangsmåde til fjernelse af pesticider fra Ginkgo biloba-ekstrakter og ekstrakter, der kan tilvejebringes ved fremgangsmåden

摘要

Process for removing pesticides from Ginkgo biloba extracts, which involves submitting an extract obtained by conventional methods to the following steps:
a. Liquid-liquid extraction of the extract to obtain a medium polarity fraction containing ginkgo terpenes and pesticides not removable with hexane, and a high polarity fraction containing ginkgo flavone glycosides;
b. crystallisation from the medium polarity fraction obtained at step a) to give an intermediate with a ginkgolide content of not less than 50%;
c. crystallisation from the residual solution obtained at step b) to give an intermediate with a bilobalide content of not less than 50%;
d. mixing of the high polarity fraction obtained at step a) with the ginkgo terpene intermediate and the bilobalide intermediate obtained at steps b) and c).