• 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.

• Journal of Life Science
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• v.29 no.12
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• pp.1371-1377
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• 2019

Oxidative stress induced by the over-production of reactive oxygen species (ROS) in the brain is the most common cause of neurodegenerative diseases such as Alzheimer's. In the present study, we investigated the protective effects of flavonoids and their glycosides, namely kaempferol, kaempferol-3-O-glucoside, quercetin, and quercetin-3-β-D-glucoside, against H₂O₂-induced oxidative stress in the C6 glial cells. The H₂O₂-treated glial cells exhibited decreased cell viability and increased ROS production when compared with normal cells. However, cells treated with each of the four flavonoids/glycosides demonstrated significantly increased viability and suppressed ROS production when compared with the H₂O₂-treated control group. These results indicate that flavonoids/glycosides attenuate oxidative stress induced by H₂O₂ in C6 glial cells. To confirm the protective molecular mechanisms, we measured pro-inflammatory factors such as inducible nitric oxide synthase, cyclooxygenase-2, and interleukin-1β. H₂O₂ treatment was seen to elevate these factors and decrease IκB-α in the C6 glial cells, while the flavonoids/glycosides induced a down-regulation of the pro-inflammatory factors and increased IκB-α, indicating a neuroprotective effects through attenuation of the inflammation. In particular, quercetin and its glycoside showed a higher neuroprotective effect than the kaempferol treatments. These results suggest that these flavonoids and their glycosides could be promising therapeutic agents for neurodegenerative diseases via the attenuation of oxidative stress.

• Korean Journal of Pharmacognosy
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• v.27 no.1
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• pp.75-79
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• 1996

Four steroids and one flavonol glycoside were isolated from the ethanol extract of the whole plant of Aconitum pseudolaeve var. erectum. Their structures were identified as ${\beta}-sitost-4-en-3-one$, 22-dihydro-stigmast-4-en-3,6-dione, ${\beta}-sitosterol$, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ and $kaempferol-3-O-{\beta}-D-glucopyranoside(astragalin)$ on the basis of spectral data.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.40-43
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• 2004

All ten compounds were isolated from the methanolic extract of the whole plants of Diodia teres through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as three iridoid glycosides, asperuloside, geniposidic acid and asperulosidic acid, a coumarin glycoside, scopolin, and six flavonoids, rutin, kaempferol-3-0-rutinoside, quercitrin, astragalin, isoquercitrin and quercetin by spectroscopic analysis.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.309-315
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• 2008

The methanol extract from the aerial parts of Aceriphyllum rossii was fractionated into ethyl acetate, n-BuOH and $H_2O$ layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc and n-BuOH layers afforded five flavonol glycosides. They were identified as astragalin (1), kaempferol 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (2), rutin (3), kaempferol 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$4)-${\alpha}$-L-rhamnopyranosyl 1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (4), and quercetin 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$4)-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (5) on the basis of spectroscopic data. All of them showed an inhibition in farnesyl protein tranferase (FPTase) activity, and rutin (3) inhibited the growth of rat H-ras cell and the cell migration of human umbilical vein endothelial cells (HUVECs).

• Applied Biological Chemistry
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• v.48 no.1
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• pp.98-102
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• 2005

The MeOH extracts obtained from whole plant of Trigonotis peduncularis Benth. were solvent fractionated using EtOAc, n-BuOH and water, successively. The EtOAc and n-BuOH fractions gave four flavonol glycosides through application of silica gel and octadecyl silica gel (ODS) column chromatographies. The chemical structures of the flavonol glycosides were determined by the interpretation of several spectral data including 2D-NMR as $kaempferol-3-O-{\beta}-{D}-glucopyranoside\;(astragalin,\;1),\;kaempferol-3-O-{\alpha}-{L}-rhamnopyranosyl\;(1{\rightarrow}6)-{\beta}-{D}-glucopyranoside\;(nicotiflorin,\;2),\;quercetin-3-O-{\alpha}-{L}-rhamnopyranosyl(1{\rightarrow}6)-{\beta}-{D}-glucopyranoside\;(rutin,\;3),\;quercetin-3-O-{\beta}-{D}-glucopyranoside\;(isoquercitrin,\;4)$. The flavonoids have been first isolated from this plant. Nicotiflorin $(100\;{\mu}g/ml)$ showed $68.3{\pm}1.2%$ of the inhibitory effect on hACAT1(human Acyl CoA: cholesterol transferase 1) activity.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.237-244
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• 1998

A study was carried out to elucidate the relation between the production of flavonol glycosides and the change of phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba by the unassisted and synergistic effects of various factors. The quercetin production showed a mixed-growth-associated pattern in cell suspension cultures. Fluorescent light and UV radiation increased phenylalanine ammonia-lyase (PAL) activity, and resulted in the increase of the production of quercetin and kaempferol ten- and four-fold, respectively, as compared to that obtained in the normal culture condition. The cell growth of Ginkgo biloba was enhanced .at higher temperatures whereas the quercetin production was at its maximum at low temperatures. Moreover, the quercetin production was increased by temperature change during the culture period. In particular, the quercetin production was at the highest level when the culture temperature was elevated from $10^{\circ}C\;to\;30^{\circ}C$. The addition of phenylalanine as a precursor in the culture medium stimulated an 8-fold increase in the production of quercetin; the addition of naringenin caused a l0-fold increase. The quercetin production was also greatly increased by feeding enzyme cofactors such as 2-ketoglutarate and ascorbic acid in the culture medium, but specific PAL activity was not increased except with phenylalanine feeding. The synergistic effect of UV radiation and naringenin feeding was observed, resulting in the increase of flavonol glycoside production at a rate higher than in any other case investigated.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.574-587
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• 2014

In this study, vertical distribution patterns of Quercus mongolica Fisch. ex Ledeb. and Q. serrata Murray in Korea were recognized and possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Jiri was inferred by flavonoid analyses. The most critical factor on distribution patterns was the altitude in accordance with temperature condition. A zonal distribution was recognized: Quercus mongolica zone in the upper area and Q. serrata zone in the lower area. In Central Korea, the range of vertical distribution of Q. mongolica was above alt. 100m, almost everywhere, whereas that of Q. serrata was from alt. 0 m to alt. 500(-700) m, and the species is rare above that altitude. But in Southern Korea, Q. serrata is found up to above alt. 1,000 m, whereas frequency of Q. mongolica reduces as elevation in decline and the species is rare below alt. 300 m, even though pure stands being formed on higher mountain slope. Altitudinal distribution of the two species, however, overlaps, where the two species occur together. Thirty-seven individuals of Q. mongolica and Q. serrata in Mt. Jiri and other area were examined for leaf flavonoid constituents. Twenty-three flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols kaempferol, quercetin, isorhamnetin, myricetin, and four compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside and by high concentration of three acylated compounds, acylated kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and by relatively low concentration or lacking of rhamnosyl flavonol compounds. There are intraspecific variations in flavonoid profiles for Q. mongolica and Q. serrata, the flavonoid profiles for individuals of two species in hybrid zone (sympatric zone) tend to be similar to each other, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through the introgressive hybridization between Q. mongolica and Q. serrata in Mt. Jiri. Therefore, Quercus crispula, occupying morphologically intermediate position between Q. mongolica and Q. serrata, is suspected of being a hybrid taxon of two putative parental species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.823-831
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• 2015

Evaluation of biological activity and analysis of functional constituents from water and ethanol extracts of four different parts of mulberry (Morus alba L.) tree were carried out to develop functional ingredients and foods using extracts of mulberry tree. The water and ethanol extracts of four different parts of mulberry tree were prepared and their biological activities and functional constituents determined by in vitro assays and HPLC, respectively. In general, ethanol extracts showed stronger biological activities and higher functional constituents than water extracts. Ethanol extracts of mulberry fruit, root bark, and twig showed stronger antioxidant ($IC_{50}=128.4{\mu}g/mL$), ${\alpha}$-glucosidase ($IC_{50}=12.0{\mu}g/mL$), and lipoxygenase ($IC_{50}=36.3{\mu}g/mL$) and tyrosinase ($IC_{50}=410.3{\mu}g/mL$) inhibitory activities, respectively, than those of other parts. Mulberry fruit and leaf showed the highest contents of anthocyanin (cyanidin 3-glucoside: 213.20 mg/100 g) and chlorogenic acid (514.97 mg/100 g), and especially ethanol extract of mulberry leaf contained higher quercetin 3-O-(6-O-malonyl)glucoside (143.25 mg/100 g) and kaempferol 3-O-(6-O-malonyl)glucoside (30.25 mg/100 g) contents without water extract of mulberry leaf. Meanwhile, mulberry twig contained both oxyresveratrol glycoside (48.90 mg/100 g) and its aglycone (21.88 mg/100 g), whereas mulberry root bark contained mostly oxyresveratrol glycoside (724.05 mg/100 g). Additionally, mulberry root bark and leaf contained much higher ${\gamma}$-aminobutyric acid (223.90 mg/100 g) and 1-deoxynojirimycin (86.07 mg/100 g) contents, respectively, than other parts of mulberry tree. These results suggest that high quality processed foods and functional foods using mixtures of mulberry fruits, leaves, twigs, and root barks should be developed for prevention and inhibition of several pathological disorders.

• Journal of Life Science
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• v.24 no.10
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• pp.1092-1101
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• 2014

In this study, the distribution patterns of Quercus mongolica and Q. serrata in Korea were investigated, and the possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Seorak was inferred by flavonoid analyses. The most critical factor in the vertical and horizontal distribution patterns of Q. mongolica and Q. serrata was the temperature, in accordance with latitude and altitude. The species showed a zonal distribution, with a Q. mongolica zone in the upper area and a Q. serrata zone in the lower area. In Mt. Seorak, Central Korea, the range of the vertical distribution of Q. mongolica was generally above an altitude of 100 m, whereas that of Q. serrata was an altitude of 0-400 m (-500) and rarely above an altitude of 500 m. However, in Mt. Jiri, Southern Korea, Q. serrata was found up to an altitude of 1,000~1,200 m, whereas the frequency of Q. mongolica was reduced at lower elevations and the species was rare below an altitude of 300 m, although pure stands were found on higher mountain slopes above an altitude of 1,200 m. The altitudinal distribution of the two species overlapped, where the two species occurred together. The leaf flavonoid constituents of thirty-four individuals of Q. mongolica and Q. serrata in Mt. Seorak and Mt. Jiri, Korea were examined. Twenty-four flavonoid compounds were isolated and identified. These were glycosylated derivatives of flavonols kaempferol, quercetin, isorhamnetin, myricetin. Five compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside, a high concentration of three acylated compounds (kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and quercetin 3-O-galactoside), and a relatively low concentration or lack of rhamnosyl flavonol compounds. Intraspecific variations, however, were found in the flavonoid profiles of Q. mongolica and Q. serrata, and the flavonoid profiles of individuals belonging to the two species in a hybrid zone (sympatric zone) tended to be similar, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through introgressive hybridization between Q. mongolica and Q. serrata in Mt. Seorak.