• YAKHAK HOEJI
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• v.38 no.4
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• pp.469-475
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• 1994

As the continued studies for Korean cultivated rhubarb, MeOH extract of the leaves was fractionated with ether, ethylacetate, and n-butanol. From the ethyl acetate fraction of MeOH extract, one flavone glycoside, apigenin-8-${\beta}$-D-glucopyranoside(vitexin, $C_{21}H_{20}O_{10}$) and from the n-BuOH fraction of MeOH extract, two flavonol glycosids, kaempferol-3-O-(2,6-di-O-rhamnopyranosyl)-${\beta}$-D-galactopyranoside$(C_{33}H_{40}O_{19})$and quercetin-3-O-rutinoside(rutin, $C_{27}H_{30}O_{16}$) were isolated and identified through the physico-chemical properties and spectroscopic evidences(UV, IR, NMR, Mass) respectively.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1060-1065
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• 2008

A novel benzoyl glucoside (4) and 13 known phenolic compounds were isolated from the leaves of Camellia japonica by a guided 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The structure of 4 was determined to be 4-hydroxy-2-methoxyphenol 1-O-$\beta$-D-(6'-O-p-hydroxylbenzoyl)-glucopyranoside (camelliadiphenoside). The 13 known compounds were identified as (E)-coniferyl alcohol (1), (-)-epicatechin (2), 4-hydroxyphenol 1-O-$\beta$-D-(6-O-p-hydroxybenzoyl) glucopyranoside (3), naringenin 7-O-$\beta$-D-glucopyranoside (5), quercetin 3-O-$\beta$-L-rhamnopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranoside (6), kaempferol 3-O-$\beta$-L-rhamnopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranoside (7), (+)-catechin (8), 1,6-di-O-p-hydroxybenzoyl-$\beta$-D-glucopyranoside (9), phloretin 2'-O-$\beta$-D-glucopyranoside (10), quercetin 3-O-$\beta$-D-glucopyranoside (11), quercetin 3-O-$\beta$-D-galactopyranoside (12), kaempferol 3-O-$\beta$-D-galactopyranoside (13), and kaempferol 3-O-$\beta$-D-glucopyranoside (14). Their chemical structures were determined by the spectroscopic data of fast atom bondardment mass spectrometry (FABMS) and nuclear magnetic resonance (NMR). Flavonoids having the catechol moiety showed significantly higher DPPH radical scavenging activity than other isolated compounds having monohydroxy phenyl group.