• Applied Biological Chemistry
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• 제43권4호
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• pp.314-316
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• 2000

• Natural Product Sciences
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• 제3권1호
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• pp.8-10
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• 1997

A new flavonol glycoside, quercetin 3-rhamnosyl $(1{\rightarrow}3)$ galactoside [5] was isolated from the leaves of M. africana. The known compounds kaempferol 3-rutinoside [1], 3'-O-methylquercetin 3-rutinoside [2], quercetin 3-rutinoside [3], and quercetin 3-rhamnosyl $(1{\rightarrow}6)$ galactoside [4] were also isolated for the first time from this plant. Their structures were determined by chemical and spectroscopic methods.

• 생약학회지
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• 제47권4호
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• pp.295-300
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• 2016

Flavonoids are widely reported to be beneficial to human health. Among flavonoids, in general, flavonoid aglycons have better biological activities than flavonoid glycosides, in that aglycons can easily penetrate through cell membrane because of their low polarity. Therefore, kaempferol, quercetin and various their glycosides were evaluated for their abilities to inhibit NO and $PGE_2$ productions in LPS-induced RAW 264.7 cells. Of these flavonoids and flavonoid glycosides, kaempferol-7-O-${\beta}$-D-glucoside(kp-7-glu) which possesses a glycoside at C-7 position of the A ring in kaempferol, potently inhibited NO, $PGE_2$ and $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 productions in LPS-induced RAW 264.7 macrophages.

• 약학회지
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• 제49권5호
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• pp.416-421
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• 2005

Cudrania tricuspidata Bereau (Moraceae) have been used for anti-inflammatory, anti-hepatotoxic, anti-hyper­tensive and anti-diabetic activities. In order to investigate the efficacy of antioxidant activity, the bio-activity guided fraction and isolation of Biologically active substance were performed. $H_{2}O,\;30\%,\;60\%,\;100%$ MeOH and acetone fractions were examined on the antioxidant activity by DPPH method. It was shown that $30\%,\;60\%,\;100\%$ MeOH fractions have sig­nificantly antioxidant activity. From $30\%$ MeOH fraction, two dihydroflavonoid glycosides dihydroquercetin 7-O-$\beta$-D-glu­copyranoside (I), dihydrokaempferol 7-O-$\beta$-D-glucopyranoside (V) were isolated and $60\%$ MeOH fraction, six flavonoids including quercetin 3-O-$\alpha$-L-rhamnopyranosyl($1\rightarrow6$)-$\beta$-D-glucopyranoside (II), quercetin 3-O-$\beta$-D-glucopyranoside (III), quercetin 7-O-$\beta$-D-glucopyranoside (IV), kaempferol 3-O-$\alpha$-L-rhamnopyranosyl($1\rightarrow6$)-$\beta$-D-glucopyranoside (VI), kaempferol 3-O-$\beta$-D-glucopyranoside (VII), kaempferol 7-O-$\beta$-D-glucopyranoside (VIII) were isolated. To investigate the antioxidant activities of each compounds, we measured radical scavening activity with DPPH method and anti-lipid per­oxidative efficacy on low density lipoprotein (LDL) with TBARS assay. Four compounds of quercetin glycosides (I, II, III, IV) showed significant antioxidant activity.

• 생약학회지
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• 제29권3호
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• pp.231-236
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• 1998

Three flavonoid glycosides have been isolated from the aerial part of Armoracia rusticana P. (Cruciferae) in Korea and identified by means of spectral analysis as $kaempferol-3-O-{\beta}-D-xylofuranoside(l)$, $kaempferol-3-O-{\beta}-D-galactopyranoside(2)$ and $kaempferol-3-O-{\beta}-D-xylofuranosyl(1\rightarrow2)-b{\beta}-D-galactopyranoside(3)$. When 1 mg/ml of the methanol extract from the aerial part of this plant was added, lipid peroxide formation in the bromobenzene-treated rat liver decreased by 64%. Among the components isolated from title plant, compounds 2 and 3 reduced the formation of lipid peroxide by 16% and 39% respectively at the concentration of ${10}^{-1}$ mg/ml.

• Food Science and Biotechnology
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• 제14권1호
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• pp.58-63
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• 2005

Ethyl acetate-soluble neutral fraction of hot water extracts from the aerial parts of Angelica keiskei showed a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Six antioxidative compounds were purified and isolated by various chromatographic procedures. Based on the analyses of FAB-MS and NMR, the isolated compounds were structurally elucidated as luteolin 7-O-${\beta}$-D-glucopyranoside (1), quercetin 3-O-${\beta}$-D-galactopyranoside (2), quercetin 3-O-${\beta}$-D-glucopyranoside (3), quercetin 3-O-${\alpha}$-D-arabinopyranoside (4), kaempferol 3-O-${\alpha}$-D-arabinopyranoside (5), and luteolin 7-O-rutinoside (6). The glycosides of flavonols and luteolin showed DPPH radical-scavenging activity. One molecule of 2, 3, 4, 6, 1, and 5 scavenged 4.2, 4.2, 4.1, 2.5, 2.2, and 1.4 molecules of DPPH radical, respectively.

• Applied Biological Chemistry
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• 제41권2호
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• pp.197-200
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• 1998

홍화 MeOH 추출물의 n-BuOH 분획으로부터 silica gel column chromatography를 반복하여 2종의 flavonoid 배당체를 분리, 정제하였다. 화합문의 화학구조를 HMBC를 포함한 NMR, MS, IR과 같은 기기분석 결과와 산가수분해반응을 이용하여 결정, 각각 $3-O-[{\beta}-D-glucopyranosyl(1{\rightarrow}2)\;{\beta}-D-glucopyranosyl]\;kaempferol$ 및 $3-O-[{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)\;{\beta}-D-glucopyranosyl]\;kaempferol$로 동정하였다. 각 화합물은 Grb2-Shc 결합저해활성$(IC_{50}:43,\;47\;{\mu}g/ml)$을 나타내었다.

• 공업화학
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• 제29권1호
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• pp.49-55
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• 2018

본 연구에서는 그라비올라의 주성분인 nicotiflorin을 분리하고 그 아글리콘 성분인 kaempferol을 얻어 세포 보호 효과 및 그 보호 메커니즘을 규명하였다. L-Ascorbic acid 및 (+)-${\alpha}$-tocopherol을 대조군으로 하여, $^1O_2$로 유도된 세포 손상에 대해 nicotiflorin 및 kaempferol의 보호 효과를 측정한 결과 nicotiflorin < (+)-${\alpha}$-tocopherol < kaempferol 순으로 보호 효과가 증가하였다. L-Ascorbic acid는 세포 보호 효과를 보이지 않았다. 이들의 세포 보호 효과 메커니즘을 밝히기 위해 singlet oxygen 소광 속도 상수, 자유라디칼 소거 활성, ROS 소거 활성 및 적혈구 세포 침투율을 측정하였다. 실험 결과, kaempferol과 그 배당체인 nicotiflorin의 세포 보호 효과에 있어서 큰 차이는 세포막에의 침투가 가장 큰 요인으로 확인되었다. 대조군 L-ascorbic acid가 항산화능은 크지만 실험 조건에서 세포막에 침투가 잘 안되어 세포 보호 효과가 나타나지 않은 것으로 확인되었다. Kaempferol과 (+)-${\alpha}$-tocopherol의 비교를 통해 세포 침투뿐만 아니라 라디칼 소거활성 및 ROS 소거 활성도 세포 보호 효과에 기여하는 것으로 나타났다. 결론적으로, 광증감 반응으로 유도된 세포막 파괴에 대한 보호작용은 항산화제들의 세포 침투, 자유라디칼 및 ROS 소거 활성이 큰 영향을 미치는 것으로 확인되었다.

• 약학회지
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• 제38권4호
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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.

• 약학회지
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• 제37권4호
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• pp.325-330
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• 1993

Four flavonoide glycosides and (-)-Epicatechin were isolated from the aqueous extracts of dried whole part of Lysimachia clethroides Duby(Primulaceae). They were 3-0-Methyl-quercetin-7-0-[$\alpha$-L- rhamnopyranosyl (1-2) glucopyranoside], Quercetin-3-0-$\beta$-D-glucopyranoside, Kaempferol-3-0-$\beta$-D-glucopyranoside, Kaempferol-3-0-[$\alpha$-L-rhamnopyranosyl (1-6)-$\beta$-D-glucopyranoside] and (-)-Epicatechin. 3-0-[$\alpha$-L-rhamnopyranosyl (1-6)-$\beta$-D-glucopyranoside]and (-)-Epicatechin. 3-0-Methyl-quercetin-7-0-[$\alpha$-L-rhamnopyranosyl (1-2)-$\beta$-D-glucopyranoside] and (-)-Epicatechin were first isolated from this plant. Their structures were elucidated by spectral analysis [$^{1}$H-, $^{13}C-$ NMR, $^{1}$H-$^{1}$H-COSY, DEPT-analysis, HMQC(Heteronuclear multiple quantum coherence), FAB-MS].