| 摘要 |
Quantitative Analysis of the Flavonoid Glycosides and Terpene Trilactones in the Extract of Ginkgo biloba and Evaluation of their Inhibitory Activity towards p Amyloid Peptide Aggregation The standard extract of Ginkgo biloba leaves (EGb761) is used clinically in Europe for the symptomatic treatment of impaired cerebral function in primary degenerative dementia syndromes. In this invention, seven flavonoid glycosides were isolated from the extract of Ginkgo biloba leaves and characterized by spectroscopic analysis. Furthermore, an UIPL chromatography method was established for the simultaneous quantification of these seven flavonoids. The inhibitory activities of these flavonoids (compounds 1-7), as well as four TTLs, i.e. ginkgolides A, B, and C and bilobalide (compounds 8-11), were evaluated towards A342 aggregation using a thioflavin T fluorescence assay. It was found that three flavonoids (compounds 1, 3 and 4) exhibited moderate inhibitory activities, whereas the other four flavonoids (compounds 2, 5, 6 and 7), as well as the four terpene trilactones, showed poor activity. This is the first report of the inhibition of AD aggregation of two characteristic acylated flavonoid glycosides (compounds 6, 7) in Ginkgo leaves, on the basis of which the structure-activity relationship of these flavonoids (compounds 1-7) was discussed. <DocRef#00128414-CX > M006.037.DRF 22 Spec draft final |
