• Korean Journal of Pharmacognosy
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• v.12 no.4
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• pp.208-210
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• 1981

From the leaves of Polygonum sachalinense Fr. Schm. (Polygonaceae) quercetin, mp $316{\sim}8^{\circ}$, and avicularin, mp 216{\sim}6^{\circ},\;[{\alpha}]^D_{20}-152^{\circ}$, were isolated and characterized by spectral data. Both are first isolation from this plant.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.93-100
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• 2014

The Acer tegmentosum (3 kg) were extracted with boiled water and the freeze dried extract powder was partitioned with $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc and n-BuOH fraction, six phenolic compounds were isolated through the silica gel, octadecyl silica gel and sephadex LH-20 column chromatography. On the basis of spectroscopic methods, such as $^1H$-NMR and $^{13}C$-NMR, and LC/MS, the chemical structures of the compounds as feniculin (1), avicularin (2), (+)-catechin (3), (-)-epicatechin (4), salidroside (5) and 6'-O-galloylsalidroside (6). In this study, compounds 1 and 2 have been first isolated from the A. tegmentosum. To provide insight into the effects of six compounds isolated from A. tegmentosum on inflammation, we investigated its effect on nitric oxide (NO) production in RAW 264.7 cells using lipopolysaccharide (LPS) stimulation. Compounds 1 and 6 slightly repressed NO production. Also, compounds 3 and 4 inhibited NO secretion with statistical significance. However, compounds 2 and 5 did not show any inhibitory effect on NO production.

• Korean Journal of Pharmacognosy
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• v.37 no.3
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• pp.177-183
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• 2006

Six compounds were isolated from EtOAc soluble fraction of the leaves of Rhododenderon schlipenbachii. On the basis of spectral data, they were identified as quercetin (1), juglanin (2), avicularin (3), quercitrin (4), afzelin (5), and hirsutrin (6), respectively.

• Natural Product Sciences
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• v.21 no.3
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• pp.170-175
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• 2015

The present study aims to detect the rare flavonoids isolated from the leaves of Persicaria glabra. The known flavonoids: quercetin (1), isorhamnetin (2), avicularin (3) and new one isorhamnetin-3-O-α-L-(6''-E-p-coumaroyl)-rhamnoside (4) were identified by HPLC, UV, IR and NMR. P. glabra has used traditionally for its analgesic, anti-inflammatory and anti-rheumatic properties. To find out the ingredients responsible for the efficiency of this plant, we have used to study the anti-microbial and anti-inflammatory activities of different extracts.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.291-295
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• 2007

Eight compounds were isolated from the whole plants of Euphorbia supina (Euphorbiaceae) through repeated silica gel, YMC gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as 7-hydroxy-6-methoxycoumarin (scopoletin) (1), p-hydroxybenzaldehyde (2), methyl gallate (3), gallic acid (4), quercetin (5), quercetin $3-O-{\alpha}-L-arabinofuranoside$ (avicularin) (6), kaempferol $3-O-{\alpha}-L-arabinofuranoside$ (juglanin) (7) and kaempferol $3-O-{\beta}-D-glucopyranoside$ (astragaline) (8) by spectroscopic (NMR and MS) analysis.

• Natural Product Sciences
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• v.27 no.4
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• pp.280-283
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• 2021

Cercidiphyllum japonicum is being used for the treatment of obesity and liver fibrosis in Korean local clinics. In the present study, we tried to develop an analytical methodology for the determination of the chemical markers of Cercidiphyllum japonicum. Four chemicals, maltol (1), chlorogenic acid (2), quercetin (3), and avicularin (4), were selected for method validation, and the analytical conditions were optimized and validated using high-performance liquid chromatography coupled with an ultraviolet detector (HPLC-UV). Additionally, the seasonal variations of four markers were monitored every month for six months. The contents of four chemicals markers were most detected in a sample collected in June.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.771-780
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• 2014

The antioxidative effects and component analysis of the Melaleuca quinquenervia leaf extracts were investigated. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from dried M. quinquenervia leaves. The DPPH (1,1-phenyl-2-picrylhydrazyl) scavenging activity ($FSC_{50}$) of ethyl acetate fraction ($10.05{\mu}g/mL$) of M. quinquenervia leaf extracts was similar to (+)-${\alpha}$-tocopherol($8.89{\mu}g/mL$) known as a typical antioxidant. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the ethyl acetate fraction ($1.61{\mu}g/mL$) and aglycone fraction ($1.07{\mu}g/mL$) of leaf extracts of M. quinquenervia on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay were similar to that of L-ascorbic acid ($1.50{\mu}g/mL$). The cellular protective effect of the extracts on the rose bengal sensitized photohemolysis of human erythrocytes was increased in a concentration dependant manner ($1{\sim}50{\mu}g/mL$). Especially, the cellular protective effects of Aglycone fraction (${\tau}_{50}=158.80min$) and 50% Ethanol extract (${\tau}_{50}=50.1{\pm}0.2min$) on the $^1O_2$-induced cellular damage of human cells were exhibited the higher than (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.0min$). TLC and HPLC were used to analyse active components in the ethylacetate fraction of the extracts. Results showed that avicularin and quercetrin were active components of the extracts. These findings suggest that the M. quinquenervia leaf extracts can be applied to new cosmetics products as an effective antioxidant ingradient.

• Natural Product Sciences
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• v.15 no.4
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• pp.234-240
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• 2009

Phytochemical investigation of the MeOH extract of the aerial parts of Bistorta manshuriensis resulted in the isolation of two cerebrosides, two lactams, six phenolic compounds and seven flavonoids. Their chemical structures were characterized by spectroscopic methods to be pinelloside (1), soyacerebroside I (2), pterolactam (3), 5-hydroxypyrrolidine-2-one (4), vanillic acid (5), caffeic acid methyl ester (6), protocatechuic acid (7), caffeic acid (8), 3,5-di-O-caffeoyl quinic acid methyl ester (9), chlorogenic acid methyl ester (10), avicularin (11), afzelin (12), quercetin (13), isoorientin (14), quercetin 3-O-${\beta}$-D-glucoside (15), quercitrin (16), and luteolin (17). The isolated compounds (1 - 4, 7, 12, 14) were isolated for the first time from this plant source and the compounds 1 - 4, 9 and 10 were first reported from the genus Bistorta. Compound 17 exhibited moderate cytotoxicity and compound 6 exhibited weak cytotoxicity against four human cancer cell lines in vitro using an SRB bioassay.

• Natural Product Sciences
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• v.10 no.1
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• pp.35-39
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• 2004

Aldose reductase (AR), the key enzyme of the polyol pathway, is known to play important roles in the diabetic complications. The inhibitors of AR, therefore, would be potential agents for the prevention of diabetic complications. In order to clarify the structural requirements of flavonoids for aldose reductase inhibitory activity, thirty flavonoids were examined. Among the thirty flavonoids, flavonols such as quercetin (5), reyneutrin (7), quercitrin (9), isoquercitrin (11), and avicularin (14) were found to exhibit much stronger AR inhibition. Lonicerin (10), amentoflavone (27) and sophoraflavanone B (30) were also showed strong inhibitory activity. Especially, quercitrin and reyneutrin exhibited the most inhibitory potency on rat lens (RL) AR. The results suggested that flavonol having the 7-hydroxyl and/or catechol moiety at the B ring exhibit strong activity. In addition, flavonols having 3-O-monosaccharide also showed stronger inhibition than free flavonols at the 3-position. These results suggested that quercitrin and reyneutrin are attributed to be the promising compounds for the prevention and/or treatment of diabetic complications.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.260-264
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• 2008

Eight compounds were isolated from the EtOAc soluble fraction of Euphorbia supina MeOH extract as the radical scavengers for antioxidant activity. Their structures were identified as kaempferol (1), quercetin (2), juglanin (3), avicularin (4), astragalin (5), isoquercitrin (6), hyperin (7), and nicotiflorin (8) by spectroscopic analysis. The antioxidant activity was evaluated by the ORAC (oxygen radical absorbance capacity) assay, which measures scavenging activity against peroxy radicals induced by 2,2'-azobis (2-methylpropionamidine) dihydrochloride, and the ORAC value is expressed as relative trolox equivalent. Compounds 4, 6, and 7 exhibited potent antioxidant activity, whereas the other compounds showed weaker activity than trolox.