• 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.

• Korean Journal of Pharmacognosy
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• v.24 no.1
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• pp.47-53
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• 1993

The seasonal variations of the major six flavonol glycosides(kaempferol 2,6-dirhamnosyl glucoside, quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside, isorhamnetin 3-O-rutinoside, quercetin 3-O-coumaroyl glucorhamnoside and kaempferol 3-O-coumaroyl glucorhamnoside) in Ginkgo biloba leaves were investigated. The contents were determined by HPLC on reversed phase $C_{18}$ column. This result showed that the percentage of six flavonol glycosides decreased during the season from 1.57% in May to 0.39% in November. The content of each flavonol glycoside indicated a similar tendency to decrease. However, the contents of rutinosides of kaempferol, quercetin and isorhamnetin fluctuated markedly than those of coumaroyl glucorhamnosides of kaempferol and quercetin and kaempferol 2,6-dirhamnosyl glucoside.

• 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.

• Korean Journal of Pharmacognosy
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• v.27 no.2
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• pp.142-145
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• 1996

We have previously reported the isolation of seven hydrolyzable tannins and nine flavonoids from Euphorbia pekinensis Ruprecht. Further investigation about the same plant has led to the isolation of kaempferol, quercetin, kaempferol $3-O-(2'-O-galloyl-{\beta}-_D-glucoside)$, quercetin 3-O-(2'-O-galloylrutinoside), ellagic acid and acetonyl geraniin. These compounds were isolated from this plant for the first time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.286-293
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• 2019

Alzheimer's disease (AD) is a neurodegenerative disease caused by accumulation of amyloid beta ($A{\beta}$) in the brain. In the present study, we investigated the neuroprotective effects of four flavonoids such as kaempferol, kaempferol-3-O-glucoside, quercetin, and quercetin-3-${\beta}$-D-glucoside against neuronal apoptosis induced by $A{\beta}$ in SH-SY5Y neuronal cells. Treatment with $A{\beta}$ decreased cell viability compared to the non-treated normal group. However, treatment with the four flavonoids increased cell viability in SH-SY5Y cells treated with $A{\beta}$. In addition, we measured the expression of apoptosis-related proteins such as Bcl-2-associated X protein (Bax) and cleaved caspase-9. Treatment with the four flavonoids down-regulated Bax and cleaved caspase-9 in $A{\beta}$-treated SH-SY5Y neuronal cells. Overall, the results of the present study demonstrated the neuroprotective effect of flavonoids by anti-apoptotic activity in $A{\beta}$-induced SH-SY5Y neuronal cells. These results suggest that these four flavonoids would be useful therapeutic and prevention agents for AD.

• Korean Journal of Pharmacognosy
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• v.27 no.2
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• pp.136-141
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• 1996

We have previously reported the isolation of nine hydrolisable tannins and five flavonoids from the aerial parts of Euphorbia ebracteolata. Further investigation about the same plant has led to the isolation of 5-O-caffeoyl quinic acid, kaempferol $3-O-(2'-O-galloyl-{\beta}-_D-glucoside)$ and euphorbin A.

• 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.

• Natural Product Sciences
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• v.4 no.4
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• pp.263-267
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• 1998

From the dried flower-buds of Syzygium aromaticum Merr. et Perry (Myrtaceae), seven compounds, i.e., eugenol (1), oleanolic acid (2), kaempferol 7-O-metylether (3), 3,3',4-tri-O-methylellagic acid (4), maslinic acid (5), ${\beta}-sitosterol-3-O-glucoside$ (6), and isorhamnetin 3-O-glucoside (7) were isolated. Compound 1 showed cyclooxygenase-2 (COX-2) inhibitory activity.

• 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.

• 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.