• Natural Product Sciences
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• v.8 no.4
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• pp.141-143
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• 2002

Two flavone glucosides have been isolated from the leaves of Helianthus tuberosus (jerusalem artichoke). Their structures were identified as kaempferol 3-O-glucoside (1) and quercetin 7-O-glucoside (2) by spectroscopic analysis and confirmed by comparison with reported data. These flavonoids were isolated for the first time from this plant part.

• International Journal of Industrial Entomology and Biomaterials
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• v.41 no.2
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• pp.45-50
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• 2020

Morus alba has white and/or purple fruits with a very sweet taste and low acidity. Most Korean mulberry trees have purple fruits. However, Baekokwang is a unique mulberry genetic resource in Korea with white fruits. In this study, flavonoids contents of Baekokwang mulberry leaf and fruit were analyzed using ultrahigh performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS) technique. UPLC-DAD-QTOF/MS chromatogram showed that 15 flavonoids and 9 flavonoids were isolated and identified from the mulberry leaf and fruit. Total flavonoids contents of Baekokwang leaves and fruits were 812.7 mg and 35.0 mg, respectively. Baekokwang leaves had 4 major flavonoids including quercetin 3-O-(6"-O-malonyl) glucoside, 235.3 ppm, kaempferol 3-O-(6"-O-malonyl) glucoside, 132.3 ppm, kaempferol 3-O-rutinoside (nicotiflorin), 108.1 ppm, and quercetin 3-O-rutinoside (rutin), 103.8 ppm. Baekokwang fruits had 3 major flavonoids including quercetin 3-O-(6"-O-malonyl) glucoside, 13.0 ppm, quercetin 3-O-rutinoside (rutin), 7.8 ppm, and kaempferol 3-O-rutinoside (nicotiflorin), 5.7 ppm. From the above results, mulberry leaves have rich flavonoids compared to its fruits.

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.238-245
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• 1996

The activity guided fractionation of $CH_2Cl_2$ soluble part of Platycarya strobilacea leaves(Juglandaceae) has led to the isolation of eight active principles, identified as 5-hydroxy-2-methoxy-1,4-naphthoquinone(1), ursolic acid(2), gallic acid(3), 4,8-dihydroxynaphthalene $1-O-{\beta}-_D-glucoside(4)$, eriodictyol(5), quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-glucoside(6)$. quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-galactoside(7)$ and quercetin $3-O-{\alpha}-_L-rhamnoside(8)$ by the means of chemical and spectral evidence, respectively.

• 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 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 Medicinal Crop Science
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• v.13 no.6
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• pp.250-254
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• 2005

The contents of flavonol glycosides, $kaempferol-3-O-{\beta}-D-glucoside$(1), $kaempferol-3-O-{\beta}-D-glactoside$ (2), $kaempferol-3-O-{\beta}-D-rhamnoside$ (3), $quercetin-3-O-{\beta}-D-glucoside$ (4) and $quercetin-3-O-{\alpha}-D-rhamnoside$ (5) in the houseleeks controlled by night-break, day-length control, and temperature during overwintering were determined to be compared with those in wild one. The contents of the flavonol glycosides 1-5 in the houseleeks were decreased roughly with warming during overwintering, and increased with longer light duration under the day-length control experiments. While warming functioned negatively on the production of the flavonol glycosides in the houseleek, longer light irradiation did positively during overwintering.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.139-144
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• 2007

In the previous study, we reported the antioxidative activity of Equisetum arvense extracts. In this study, its inhibitory effect on elastase and components were investigated. Aglycone fractions obtained from the deglycosylation reaction of ethylacetate fraction among the Equisetum arvense extracts, showed 4 bands and 4 peaks in TLC and HPLC experiments, respectively. Four components were identified as luteolin(composition ratio, 19.12%), quercetin(12.87), apigenin(15.81) and kaempferol(52.20). TLC chromatogram of ethylacetate fraction of Equisetum arvense extract revealed 7 bands and HPLC chromatogram showed 8 peaks, which were identified as kaempferol-3,7-O-diglucoside(composition ratio, 15.74%), luteolin-5-O-glucoside(galuteolin, 11.91), apigenin-5-O-glucoside(12.91), kaempferol-3-O-glucoside(astragalin, 27.94), quercetin-glycoside(10.81, structure was not determined), kaempferol-glycoside (12.33, structure was not determined), luteolin(3.72) and apigenin(4.62) in the order of elution time. The inhibitory effect of aglycone fraction on elastase($IC_{50}$, $9.8{\mu}g/mL$) was very high. But ethylacetate fraction(flavonoid glycosides) rarely exhibited the inhibitory activity on elastase. Combined with the previous results of the antioxidative activity of Equisetum arvense extracts, it is concluded that the inhibitory activity on elastase of the aglycone fraction could be applicable to new functional cosmetics for smoothing wrinkles.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.371-376
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• 1999

By cytotoxicity screening of the 65 Korean medicinal plants against leukemia L1210 and P388D$_{1}$ cell line using the MTT assay in vitro, Albizzia julibrissin was studied. This plant was extracted with MeOH and MeOH extract was solvent-fractionated with CHCl$_{3}$, EtOAc and n-BuOH in sequence. Each fraction by various solvents system was purified by column chromatography and preparative TLC, and four compounds were isolated. The structure of each compound was deduced from UV, IR, $^{1}$H-HMR, $^{13}$ C-NMR and CI-MS spectral data. The cytotoxic activity ($IC_{50}$/_ of the compounds, quercetin-3-rhamnoside, 4',5,7-trihydroxyfla-van-3-glucoside, spinasterol-3-glucoside and acacic acid lactone, were evaluated as 5 $\mu\textrm{g}$/ml, 2$\mu\textrm{g}$/ml, 1 $\mu\textrm{g}$/ml against L1210 and as 9$\mu\textrm{g}$/ml, 10$\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml and 0.9 $\mu\textrm{g}$/ml against P388D$_{1}$, respectively.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.414-421
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• 1998

In order to compare the suppressive effect of quercetin and its glycosides, such as quercitrin (quercetin-3-rhamnoside), isoquercitrin (quercetin-3-glucoside), hyperin (querceti n-3-galactoside)and rutin (quercetin-3-rhamnosyl glucoside), on the genotocicity by benzo(a)pyrene(B(a)P), in vitro sister chromatid exchange(SCE) test using mouse spleen lymphocytes and in vivo micronucleus test using mouse peripheral blood were performed. B(a)P-induced SCEs in vitro were slightly decreased by the simultaneous treatment of quercetin and its glycosides, although there was no significant decrease. On the other hand, MNU induced micronucleated reticulocytes(MNRL7s) in vivo were significantly decreased with a dose-dependent manner in all compounds tested. However, there were no differences between quercetin aglycone and glycosides in the suppressive effects under experimental condition of this study. To elucidate, the action mechanism of quercetin aglycone and its glycosides against B(a)P-induced genotoxicity, the assay of DNA binding with B(a)P was studied. Quercetin aglycone and its glycosides inhibited B(a)P metabolism in the presence of S-9 mix and decreased the B(a)P/DNA binding in the calf thymus DNA with S-9 mix. These results suggest that antigenotoxicity of quercetin antiglycosides on B(a)P-induced genotoxicity is due to decrease of DNA binding with B(a)P through the inhibition of metabolism with B(a)P in the calf thymus DNA. Therefore, quercetin and its glycosides may act as an antigenotoxicity agent and may be useful as a chemopreventive agent of polycyclic aromaic hydrocarbons like B(a)P.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.385-389
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• 2014

Flavonols as a major kind of plant secondary metabolites are known for health-promoting compounds in onions (Allium cepa L.). The objectives of this study are to determine profiles of flavonol glycosides in different 75 onion accessions. A total of five flavonols (quercetin 3,4'-diglucoside, Q34'diG; quercetin 3-glucoside, Q3G; quercetin 4'-glucoside, Q4'G; isorhamnetin 4'-glucoside, I4'G; quercetin, Q) were identified from onion accessions. In positive ion mode using LC-ESI-MS, individual flavonols were confirmed from one and two glycosylation binding with aglycone such as quercetin and isorhamnetin. Total flavonol contents were distributed in white onion (range of 0.18-6.47 mg/g DW) and purple onion accessions (range of 2.39-6.47 mg/g), respectively. The mean of flavonol contents in purple onion (4.41 mg/g) showed 1.4-fold higher than white onion (3.23 mg/g). The Q34'diG and Q4'G were considered as the major compounds of flavonol glycosides in onion accessions.