| 摘要 |
PURPOSE: To obtain an extract containing most of ginkgolide and bilobalide, comprising a high content of a flavone glycoside substantially not containing an alkylphenol compound, by treating an extract from Ginkgo biloba leaf by a specific method. CONSTITUTION: This extract comprises 20-30wt.%, especially 22-26wt.% of a flavone glycoside, 2.5-4.5wt.% of the total of ginkgolide A, B, D and D, 2.0-4.5wt.% of bilobalide, contains <10ppm, especially <1ppm of an alkylphenol and <10wt.% of proanthocyanidin, is useful for treating peripheral and cerebral artery blood flow disorder and has no danger of allergic reaction. The extract is obtained by removing a lipophilic component from an extract of Ginkgo biloba leaf, treating the extract with ammonium sulfate, subjecting the treated substance to an extraction treatment with methyl ethyl ketone or a mixture of methyl ethyl ketone and acetone, treating the extract with a lead compound and an insoluble polyamide. |
