• Korean Journal of Medicinal Crop Science
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• v.18 no.5
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• pp.305-310
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• 2010

Taxifolin-3-O-$\beta$-D-xylopyranoside and quercetin-3-O-$\alpha$-L-rhamnopyranoside were isolated from an EtOAc-soluble extract of the leaves of Chamaecyparis obtuse. Quercetin-3-O-$\alpha$-L-rhamnopyranoside was found to possess a potent inhibitory activity of human recombinant aldose reductase in vitro, its $IC_{50}$ value being $11.5\;{\mu}M$. Kinetic analysis showed that quercetin-3-O-$\alpha$-L-rhamnopyranoside exhibited uncompetitive inhibition against DL-glyceraldehyde. Also, quercetin-3-O-$\alpha$-L-rhamnopyranoside suppresses sorbitol accumulation in rat lens under high glucose conditions, demonstrating the potential to prevent sorbitol accumulation in vivo. These results suggest that this compound may be a promising agent in the prevention or treatment of diabetic complications.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.253-256
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• 2013

Six flavonoid compounds were isolated from the underground parts of Curcuma longa (Zingiberaceae) through repeated column chromatography. Their chemical structures were elucidated as kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl(1${\rightarrow}$2)-O-${\alpha}$-L-rhamnopyranoside (1), quercetin-3-O-${\alpha}$-L-rhamnopyranosyl(1${\rightarrow}$2)-O-${\alpha}$-L-rhamnopyranoside (2), quercetin-3-O-${\beta}$-Dglucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside (3), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (5), and quercetin (6), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.16-21
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• 2013

The fruits of Pourthiaea villosa were extracted with methanol and its extract was fractionated with n-hexane, methylene chloride, ethyl acetate and n-butanol. Repeated column chromatography of silica gel, sephadex LH-20 and HPLC led to the isolation of nine phenolic compounds from ethyl acetate soluble fraction. The chemical structures were elucidated as kaemferol-3-O-${\beta}$-D-glucopyranoside (astragalin) (1), isorhamnetin-3-O-${\beta}$-D-glucopyranoside (2), kaempferol-3-O-${\beta}$-D-xylopyranosyl($1{\rightarrow}2$)-${\alpha}$-L-rhamnopyranoside (3), caffeic acid (4), quercetin-3-O-${\beta}$-D-xylopyranosyl($1{\rightarrow}2$)-a-L-rhamnopyranoside (5), quercetin-3-O-${\beta}$-D-xylopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranoside (6), quercetin-3-O-${\beta}$-D-xylopyranosyl($1{\rightarrow}2$)-${\beta}$-D-galactopyranoside (7), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (quercitrin) (8), and kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (afzelin) (9) by spectroscopic techniques. These compounds were isolated from this plant for the first time.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.193.1-193.1
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• 2003

Activity-guided separation for the aerial parts of Rodgersia podophylla A. Gray gave a new acylated flavonoid, quercetin 3-O-${\alpha}$-L-(5$^2$-acetyl)-arabinofuranoside (1), together with six known flavonoids (2-7). Their hepatoprotective activities were determined by using the primary cultures of rat hepatocytes injured by H$_2$O$_2$. Quercetin 3-O-${\alpha}$-L-(3$^2$-acetyl)-arabinofuranoside (3), kaempferol 3-O-${\alpha}$-L-rhamnopyranoside (5) and quercetin 3-O-${\alpha}$-L-rhamnopyranoside (6) exhibited hepatoprotective activities comparable to silybin at the concentration of 50 mM (45.7, 50.8 and 57.3 %, respectively), and the new flavonoid 1 showed hepatoprotective activity at the concentration of 100mM (50.1%).

• YAKHAK HOEJI
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• v.44 no.1
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• pp.41-46
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• 2000

Phytochemical examination of the leaves of Alnus maximowiczii Call, one of the indigenous Alnus species grows in Korea, has led to the isolation of three flavonoids. Structure of these flavonoids were elucidated as quercetin-3-O-$\beta$-D-glucopyranoside (1) , quercetin-3-O-$\alpha$-L-rhamnopyranoside (2) and myricetin-3-O-$\alpha$-L-rhamnopyranoside (3) respectively by means of physico-chemical and spectral evidences.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.275-281
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• 2014

After harvesting the medicinal parts of Curcuma longa, the remaining underground parts were discarded. From the remaining underground parts of Curcuma longa quercetin-3-O-${\beta}$-D-glucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside (Q37) was isolated. The antioxidant activities in vitro and lifespan-extension effect of Q37 were elucidated using the Caenorhabditis elegans. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of Q37 showed similar potent activities in comparison with vitamin C. Q37 also showed potent superoxide quenching activities as measured by the riboflavin- and xanthine-originated superoxide quenching activity tests. Q37 prolonged lifespan of worms under normal culture condition. In terms of protective effect of Q37 on the stress conditions such as thermal and oxidative stresses, Q37-treated worms exhibited enhanced survival rate, as compared to control worms. To know the possible mechanism of Q37-mediated increased lifespan and stress resistance of worms, we examined the activities of Q37on superoxide dismutase (SOD), and invested intracellular reactive oxygen species (ROS) levels. The results revealed that Q37 was able to elevate SOD activity of worms and reduce intracellular ROS accumulation in a dose-dependent manner.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.336-341
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• 2011

As part of an ongoing search for natural plants with antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract of the twigs of Galium spurium L. (Rubiaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of nine compounds, asperulosidic acid methyl ester (1), asperuloside (2), caffeic acid (3), kaempferol-3-O-L-rhamnopyranoside (4), quercetin-3-O-[${\alpha}$-Lrhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (5), isorhamnetin-3-O-glucopyranoside (6), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (7), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (8), and quercetin (9). Their structures were elucidated by spectroscopic studies. Compounds 1, 3-8 were isolated for the first time from this plant. Among them, compounds 3 and 9 showed the significant radical scavenging effects on DPPH, and compounds 3 and 7 showed the potent riboflavin originated superoxide quenching activities.

• Natural Product Sciences
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• v.18 no.2
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• pp.111-115
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• 2012

In the course of screening for antioxidant compounds by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cyperus flaccidus (Cyperaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of ten compounds, kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside (1), caffeic acid (2), quercetin-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (3), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (5), luteoiln-7-O-${\beta}$-D-glucopyranoside (6), kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (7), luteoiln (8), quercetin (9) and quercetin-3-O-${\beta}$-D-glucuronide (10). Their structures were elucidated by spectroscopic studies. Compounds 1 - 10 were isolated for the first time from this plant. Among them, compounds 2, 8 and 9 showed the significant radical scavenging effects on DPPH, and the potent xanthine-originated superoxide quenching activities.

• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.53-60
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• 2001

2kg of the dried leaves of chamaecyparis obtusa Endlicher were ground, extracted with acetone-$H_2O$(7:3, v/v), concentrated, and fractionated with a series of hexane, $CH_2Cl_2$, EtOAc and water on a separatory funnel. Each fraction was freeze dried to give dark-brown powder and a EtOAc soluble portion of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of the isolated compounds. The leaves of chamaecyparis obtusa Endlicher contained a large amount of taxifolin-3-O-${\beta}$-D-xylopyranoside and (+)-catechin in addition to a small amount of quercetin-3-O-${\alpha}$-L-rhamnopyranoside.

• YAKHAK HOEJI
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• v.39 no.6
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• pp.600-609
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• 1995

Studies on the pharmaco-constituents from the leaves of Cercts chinensis which have been used for the treatment of inflammation, contusion, dilated blood, pain of heart and stomach, edema, etc. in Korean folk remedies were carried out. Dried leaves of the plant were extracted with MeOH. The MeOH extract was suspended in distilled water and subsequently fractionated with $Et_{2}O$ and n-BuOH. From the $Et_{2}O$ and n-BuOH fractions, six phenolic compounds were isolated and identified as myricitrin($C_{21}H_{20}O_{12}, {\;}m.p.{\;}199~200^{\circ}$. $4myricetin-3-O-{\alpha}-L-rhamnopyranoside$), kaempferol($C_{15}H_{10}O_{6}, {\;}m.p. 276^{\circ}$), quercetin($C_{15}Ha_{10}O_{7}, {\;}m.p.{\;}313~314^{\circ}$), quercitrin ($C_{21}H_{20}O_{12}, {\;}m.p.{\;}176~178^{\circ}, {\;}quercetin-3-O-{\alpha}-L-rhamnopyranoside$), gallicin ($C_{8}H_{8}O_{5}, {\;}m.p.{\;}202~203^{\circ}$. methyl gallate), gallic acid ($C_{7}H_{6}O_{5}, {\;}m.p.{\;}260~265^{\circ}) through their physico-chemical data and UV, IR, EI-MS, $^{13}C-NMR$, and $^{1}H-NMR$ analysis with authentics.