Method for extracting kadsurin D from kadsura longepedunculata

The invention discloses a method for extracting kadsurin D from kadsura longepedunculata. The method comprises the following steps: extracting, dissolving kadsura longepedunculata, extracting, and mixing an extract product with silica gel, so as to obtain a first product; feeding the first product to a silica gel column, and eluting the first product with mixed liquid of chloroform and acetone, so as to obtain a first elution product; carrying out thin layer chromatography on the first elution product; observing and developing under ultraviolet light, merging the same phases, sequentially comparing with a standard sample of the kadsurin D, and finding out and extracting a crude sample containing the kadsurin D, so as to obtain a first crude sample; feeding the first crude sample to a reverse-phase silica gel column; eluting the first crude sample with a methanol solution, so as to obtain a second elution product containing the kadsurin D; and purifying the second elution product, so as to obtain the kadsurin D. Through gradient elution of the kadsurin D, the column efficiency can be effectively improved, the separating capacity of the kadsurin D is improved, and the high-purity kadsurin D is finally obtained.