Structure Identification: |
Phytochemistry. 2001 Dec;58(8):1251-6. | Coumaroyl flavonol glycosides from the leaves of Ginkgo biloba.[Pubmed: 11738417 ] |
Two coumaroyl flavonol glycosides, isorhamnetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], and kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, were isolated from the n-BuOH extract of Ginkgo biloba leaves.
METHODS AND RESULTS:
These two, together with six other flavonol glycosides,
kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside] (Kaempferol 3-O-beta-(6''-p-coumaroyl)glucopyranosyl(1->2)-alpha-L-rhamnopyranoside),
quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside] (Quercetin 3-O-beta-(6''-p-coumaroyl)glucopyranosyl(1->2)-alpha-L-rhamnopyranoside),
quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside,
quercetin 3-O-beta-D-glucopyranosyl-(1-2)-alpha-L-rhamnopyranoside, quercetin 3-O-beta-rutinoside, and quercetin 3-O-beta-D-glucopyranoside, showed profound antioxidant activities in DPPH and cytochrome-c reduction assays using the HL-60 cell culture system. |
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