• Title/Summary/Keyword: 2DNMR

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Flavonol Glycosides with Antioxidant Activity from the Aerial Parts of Epimedium koreanum Nakai

  • Kim, Eun-Sil;Kim, Mi-Kyung;Kang, Hyun-Kyu;Park, Young-In;Dong, Mi-Sook;Kim, Dong-Hyun;Chung, Ha-Sook
    • Natural Product Sciences
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    • v.14 no.4
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    • pp.233-238
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    • 2008
  • The aerial parts of Epimedium koreanum Nakai have been used to stimulate hormone secretion in treating impotence. Ten flavonol glycosides, 3,4,5-trihydroxy-8-prenylflavone 7-O-[${\beta}$-D-glucopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranoside] (1), hyperoside (2), icarisid II (3), 2"-O-Rhamnosylicarisid II (4), epimedin A (5), epimedin B (6), epimedin C (7), icariin (8), hexandraside E (9), and epimedoside A (10) were isolated from the an ethylacetate soluble extracts of the aerial parts of Epimedium koreanum Nakai through activity-monitord fractionation and isolation method. The structures of compounds 1 - 10 were elucidated by high resolution fast atom bombardment mass spectrometry and two dimentional nuclear magnetic resonance spectroscopy analysis. Compounds 1 and 4 showed potent antioxidant activity, with $IC_{50}$ values of 19.7 and 11.5 ${\mu}g$/mL and 88.2 and 90.5 ${\mu}M$, respectively.

Isolation of Antioxidant and Antibrowning Substance from Chionanthus retusa Leaves (이팝나무 잎으로부터 항산화 및 항갈변물질의 분리)

  • Lee, Young-Nam;Jeong, Chang-Ho;Shim, Ki-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.9
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    • pp.1419-1425
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    • 2004
  • This study was performed to examine in vitro antioxidative activities such as DPPH radical scavenging activity, reducing power and tyrosinase inhibitory effect of various solvent fractions from Chionanthus retusa leaves. Ethyl acetate fraction showed potent antioxidative activity and tyrosinase inhibitory effect. The active compound was isolated from the butanol fraction by silica gel column chromatography and MPLC. The isolated compound was luteolin-4'-O-glucoside determined by $^1H$, $^{13}C$-NMR and 2D NMR. Compared with several antioxidant compounds, luteolin-4'-O-glucoside exhibited effective DPPH radical scavenging activity and reducing power in a concentration dependent manner. Bioassay with pure luteolin-4'-O-glucoside showed a dose-independent inhibitory effect on L-DOPA oxidation by mushroom tyrosinase and its $IC_{50}$ values were established as 23.2 ${\mu}g/mL$. Therefore, we may suggest that luteolin-4'-O-glucoside can be used as a food additive possessing the potent antioxidative activity and skin-whitening cosmetic material.