• YAKHAK HOEJI
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• v.36 no.6
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• pp.556-562
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• 1992

Sevral flavonoids were isolated from the ethanol extract of Carthami flos which has been used in treatment of uterin congestion and also as analgesic and antiinflammatory. They were elucidated as kaempferol, quercetin, 6-hydroxy kaempferol, kaempferol 3-glucoside (Astragalin), quercetin 3-glucoside (isoquercitrin), quercetin 7-glucoside (quercimeritrin), kaempferol 3-rutinoside and quercetin 3-rutinoside (rutin). The structures of the isolated compounds were established by spectroscopic and chemical methods.

• 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.15 no.4
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• pp.246-249
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• 2009

Column chromatographic separation of the MeOH extract from the aerial parts of Thesium chinense TURCZ led to the isolation of two norsesquiterpenes (1 - 2), two phenylpropanes (3 - 4) and four flavonoids (5 - 8). Their structures were determined by spectroscopic means to be 5,6-epoxy-3-hydroxy-7-megastigmen-9-ene (1), (-)-loliolide (2), methyl-p-hydroxycinnamate (3), methyl caffeate (4), kaempferol (5), kaempferol-3-O-${\beta}$-Dglucopyranoside (6), kaepmferol-3,7-di-O-${\beta}$-D-glucopyranoside (7) and kaempferol-3-O-${\beta}$-D-glucopyranoside-6''-(3-hydroxy-3-methylglutarate) (8). Compounds 1 - 4, 7 and 8 were first isolated from this source. The isolated compounds were evaluated for their cytotoxicty in vitro using the sulforhodamin B bioassay (SRB).

• Natural Product Sciences
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• v.6 no.3
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• pp.135-138
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• 2000

MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity$(EC_{50},\;50\;{\mu}g)$ From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as ${\beta}-sitosterol$, methyl 4-hydroxy-3,5-dimethoxycinnamate, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, ${\beta}-sitosterol$ and ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ showed no antioxidant activity. $EC_{50}$ values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and $12\;{\mu}g$, 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.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.220-223
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• 2013

In the course of screening tyrosinase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Smilax china leaves showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in 12 phenolic compounds, which were identified as 4-hydroxybenzoic acid (1), 3,4-dihydroxybenzaldehyde (2), 3,4-dihydroxybenzoic acid (3), 3,4-dihydroxyacetophenone (4), 3-hydroxy-4-methoxy benzoic acid (5), trans-p-hydroxycinnamic acid (6), cis-p-hydroxycinnamic acid (7), trans-resveratrol (8), cis-resveratrol (9), dihydroresveratrol (10), moracin M (11) and kaempferol (12). Compounds 1-11 were first reported from this plant. Among the isolated compounds, compounds 2, 8, 9 and 12 showed strong inhibition on tyrosinase activity.

• Natural Product Sciences
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• v.14 no.4
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• pp.227-232
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• 2008

Phytochemical further investigation of the chloroform extract of the aerial parts of Crucianella maritima L. (Rubiaceae) growing in Egypt resulted in the isolation of a new anthraquinone; 3-formyl-1-hydroxy-2-methoxy anthraquinone (3) along with the four known compounds isolated for the first time from the genus Crucianella; alizarin-1-methyl ether (2), 1,4-dihydroxy-2-methoxy anthraquinone (5), 1, 3, 6-trihydroxy-2-methoxy anthraquinone (7) and the flavonol kaempferol (8), beside four known compounds previously isolated from the same plant. The structures of the isolated compounds were established based on different spectroscopic data including UV, IR, EIMS, 1D and 2D-NMR. Moreover, the antioxidant and antimicrobial activities of the isolated compounds were evaluated.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1280-1285
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• 2005

Using the nodY::lacZ fusion system in Bradyrhizobium japonicum USDA 110, 22 flavonoids, which have structurally different features, were tested to define the role of the substituted functional groups as an inducer or inhibitor for the nod gene expression. A functional ,group of 4'-OH on the B-ring and the double bond between 2-C and 3-C on the C ring were required to induce the nod gene expression in B. japonicum USDA 110. In the case of isoflavones, the 4'-methoxyl group, which blocks the open 4'-OH functional group, did not significantly lower inducing activity, as compared with isoflavones with 4'-OH. However, all flavonols tested, which have a 3-OH functional group on the C-ring, did not induce, but inhibited the nod gene expression. Flavone, 7-hydroxyflavone, and kaempferol (5,7,4'-trihydroxyflavonol) at $1\;{\mu}M$ concentration significantly inhibited the nod gene expression induced by 7,4'-dihydroxyflavone. However, 7-hydroxy-4'-methoxyflavone at $1\;{\mu}M$ concentration showed a synergistic effect with genistein and 7,4'-dihydroxyflavone on the induction activity.

• Natural Product Sciences
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• v.17 no.3
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• pp.175-180
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• 2011

Eleven compounds were isolated from fresh leaves of Abies koreana (Pinaceae), and structures of these compounds were determined to be 3-hydroxy-2-methyl-4-pyrone (1), maltol-3-O-${\beta}$-D-glucoside (2), (-)-epicatechin (3), naringenin 7-O-${\beta}$-D-glucopyranoside (4), naringenin-7-O-rhamnoglucoside (5), kaempferol 3-O-${\beta}$-D-glucopyranoside (6), (+)-isolariciresinol (7), secoisolariciresinol (8), rhododendrol (9), ferulic acid (10) and 4-(4-hydroxyphenyl)butan-2-one (rheosmin) (11) by comparing $^1H$-, $^{13}C$-NMR and MS spectroscopic data with reference values. Compounds 3, 5, 7, 8, 9, 10, 11 were isolated for the first time from A. koreana. Among eleven isolates, compounds 1, 7 and 11 showed inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglia in a concentration dependent manner.

• YAKHAK HOEJI
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• v.34 no.5
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• pp.348-364
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• 1990

The activities of twenty-one flavonoids and their related compounds on the hypersensitivity reaction against various antigens were studied in vitro and in vivo. 1. Generally flavonoids inhibited significantly the homologous passive cutaneous anaphylaxis (PCA) induced by reaginic antibody as compared as anaphylaxis by compound 48/80-induced mast cell degranulation, and so more strongly active in the IgE-mediated anaphylaxis than non-IgE-mediated anaphylaxis. 2. Flavonids inhibited remarkably Arths reaction, hemolysin titer, delayed hypersensitivity, haemagglutinin titer, rosette forming cells and plague forming cells against sheep red blood cells, and so it exhibited that flavonoids inhibited type 2, 3 and 4 hypersensitivity. 3. Quercetin, kaempferol, hesperetin, disodium cromoglycate, malvin and baicalein were active dose-dependently in the all types of hypersensitivity. Fisetin, daidzein, morin, narigin, flavone, catechin, rutin, hesperidin, neophsperidin, apigenin and chrysin were significantly active in the various types of hypersensitivity, but apigenin, rutin and catechin were less active in the delayed hypersensitivity. Taxifolin was significantly active in PCA and histamine-induced anaphylaxis except other types of hypersensitivity. Rotenone and cyanin also inhibited all types of hypersensitivity, but they are toxic. 4. Based on these results from hypersensitivity, the following flavonoid structure-activity relationships became apparent. 1) Flavonoids with $C_{2-3}$ double bond in C-ring were more active than that of $C_{2-3}$ saturation. 2) Flavonoids with $C_4$ ketone group in C-ring were more active than abscence of them except catechin and malvin. 3) Flavonoids with benzene ring at positions 2 or 3 in C-ring exhibited same activities. 4) Flavonoids with opening of the C-ring does not abolish their activities. 5) The glycosylated flavonoids in position 3 or 7 was less active than their aglycone. 6) Flavonoids with the more hydroxy group in A and B-ring were more active. 7) Flavonoids with or without $C_3-OH$ did not change their activities.