• Journal of Life Science
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• v.28 no.5
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• pp.509-516
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• 2018

Five phenolic compounds were isolated from the ethyl acetate fraction of leaves from Stewartia koreana, and their nitric-oxide (NO) inhibitory activities were measured to identify the major active constituents responsible for the efficacy of the extract against inflammatory reactions. These five compounds were quercetin (1), quercitrin (2), hyperin (3), quercetin-3-O-(6"-O-galloyl)-${\beta}$-D-galactopyranoside (4), and kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside (5). Among the separated compounds in the EtOAc fraction, compounds 4 and 5 were isolated for the first time, and no study has yet reported their anti-inflammatory effects. The compounds were identified by spectroscopic analysis, and the isolated compounds showed significant NO inhibitory effects in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Compound 5 showed the most potent inhibitory effect (63.35% inhibition) against LPS-induced NO production compared to that of compound 1 (17.17%), compound 2 (5.0%), compound 3 (3.92%), and compound 4 (6.32%) at $10{\mu}g/ml$ concentration. NO production was inhibited by suppressing the protein expression of inducible nitric-oxide synthase in LPS-stimulated RAW 264.7 macrophages. These results indicate that kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside might be the major active compound responsible for the anti-inflammatory effects of S. koreana.

• Natural Product Sciences
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• v.10 no.6
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• pp.330-334
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• 2004

Four isoflavonoids and three flavonoids, and a gallotannin were isolated from the fruits of Sophora japonica (Leguminosae). Their structures were identified as genistein (1), sophoricoside (2), genistein-4'-O--L-rhamnopyranoside (3), $genistein-4'-O-{\alpha}-L-rhamnopyranosly-(1{\rightarrow}2)-{\beta}-D-glucopyranoside$ (4), $kaempferol-3-O-{\alpha}-D-sophoroside$ (5), $kaempferol-3-O-{\beta}-D-glucopyranosyl-(1{\rightarrow}2)-{\alpha}-L-rhamnopyranosly-(1{\rightarrow}6)-{\beta}-D-glucopyranoside$ (6), rutin (7) and gallic acid $4-O-{\beta}-D-(6'-O-galloyl)-glucopyranoside$ (8) by chemical and spectroscopic analysis and comparisons with previously reported spectral data. Compounds 3 and 8 were isolated for the first time from this plant. Anti-oxidative activity was evaluated for the isolated compounds. 8 exhibited potent anti-oxidative activity against the radical scavenging ability of DPPH with the $IC_{50}$ value of $17.1\;{\mu}g/ml$.

• Korean Journal of Pharmacognosy
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• v.48 no.4
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• pp.339-342
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• 2017

Quercus mongolica (QM) is a species of Quercus native to Eastern Mongolia, Siberia, China, Japan, and Korea. QM has been used as Korean traditional medicine for the treatment of inflammation of the skin. Present work, the validation and content determination of the phenolic compounds which were isolated from the leaves of QM, including pedunculagin (1) and kaempferol-3-O-(6"-galloyl)-${\beta}$-D-glucopyranoside (2) were conducted through High-Performance Liquid Chromatography (HPLC). As a result, the contents of these compounds were 4.14% and 0.76% in QM extract, respectively.