• Animal cells and systems
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• v.7 no.4
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• pp.327-330
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• 2003

We analyzed and compared profiles of flavonols extracted from leaves and exocarps of the grape Kyoho by TLC, HPLC and UV spectrophotometry. In the exocarps, quercetin 3-O-glucoside was the main compound while isorhamnetin 3-O-glycoside (I) was present in minor amounts. In leaves, on the other hand, quercetin 3-O-glucoside and quercetin 3-O-glucoside-7-O-glucronide were the major compounds while isorhamnetin 3-O-glycoside (II) and kaempferol 3, 7-O-diglycoside were present in minor amounts.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.282-290
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• 2005

The MeOH extract of the the leaves of Salix hallaisanensis (Salicaceae) was partitioned successively with $CHCl_3$, 20% MeOH, 40% MeOH and 60% MeOH solution. From the fractions obtained, 9 compounds were isolated, $diosmetin-7-O-{\beta}-d-glucoside$ (I), $diosmetin-7-O-{\beta}-D-glucosyl-(1{\rightarrow)6)-{\beta}-d-glucoside$ (II), $diosmetin-7-O-{\beta}-d-xylosyl-(1{\rightarrow}6)-{\beta}-D-glucoside$ (III), $quercetin-3-O-{\beta}-d-galactoside$ (hyperoside) (IV), $quercetin-3-O-{\alpha}-l-rhamnosyl-(1{\rightarrow}6)-{\beta}-D-glucoside(rutin)$ (V), luteolin (VI), $luteolin-7-O-{\beta}-d-glucoside$ (VII), $kaempferol-3-O-{\alpha}-l-rhamnosyl-(1{\rightarrow}6)-{\beta}-D-glucoside$ (VIII), and (+)-catechin (IX).

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.313-319
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• 2002

A total of eight flavonoids (1-8), including a novel $quercetin-7-o-(6"-o-acetyl)-{\beta}-D-glucopyranoside$ (6) and seven known flavonoids, luteolin (1), quercetin (2), luteolin $7-o-{\beta}-D-glucopyranoside$ (3), $luteolin-7-o-(6"-Ο-acetyl)-{\beta}-D-glucopyranoside$ (4) quercetin $7-o-{\beta}-D-glucopyranoside$ (5), acacetin 7-o-{\beta}-D-glucuronide (7) and apigenin-6-C-{\beta}-D-glucopyrano $syl-8-C-{\beta}-D-glucopyranoside$ (8), have been isolated from the leaves of the safflower (Carthamus tinctorius L.) and identified on the basis of spectroscopic and chemical studies. The antioxidative activity of these flavonoids was evaluated against 2-deoxyribose degradation and rat liver microsomal lipid peroxidation induced by hydroxyl radicals generated via a Fenton-type reaction. Among these flavonoids, luteolin-acetyl-glucoside (4) and quercetin-acetyl-glucoside (6) showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin (1), quercetin (2), and their corresponding glycosides (3 & 5) also exhibited strong antioxidative activity, while acacetin glucuronide (7) and apigenin-6,8-di-C-glucoside (8) were relatively less active.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.361-366
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• 2019

Isorhamnetin 3-O-glucoside, a member of the flavonol group, has been reported to be effective for inflammatory and ulcer, as well as to alleviate diabetic complications such as neuropathy, nephropathy and retinopathy. Isorhamnetin 3-O-glucoside has been extracted from several plants. Biotransformation is a valuable tool, which is used to produce value-added chemicals with inexpensive compounds. To synthesis isorhamnetin 3-O-glucoside from quercetin, two genes (PGT E82L and ROMT-9) were introduced into Escherichia coli, respectively. In order to synthesis isorhamnetin 3-O-glucoside from quercetin, a co-culture fermentation system was developed by optimizing the medium and temperature for biotransformation, the cell mix ratio, Isopropyl-β-ᴅ-thiogalactoside induction time, and quercetin feed concentration. Finally, isorhamnetin 3-O-glucoside was biosynthesized up to 181.2 mg/L under the optimized biotransformation condition, which was higher 4.7 times than previously reported (39.6 mg/L).

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.717-729
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• 2019

The chemical informs about 70 individual phenolic compounds were constructed from various lettuce samples based on literature sources and analytical data. A total of 30 phenolic compounds including quercetin 3-O-glucuronide, quercetin 3-O-(6''-O- malonyl) glucoside, cyanidin 3-O-(6''-O-malonyl)glucoside, chlorogenic acid and chicoric acid as major components were identified in 6 lettuce samples from Korea using UPLC-DAD-QToF/MS on the basis of constructed library. Among these, quercetin 3,7-di-O-glucoside(m/z 627 [M+H]⁺), quercetin 3-O-(2''-O-malonyl)glucoside(morkotin C, m/z 551 [M+H]⁺), quercetin 3-O-(6''- O-malonyl)glucoside methyl ester(m/z 565 [M+H]⁺), 5-O-cis-p-coumaroylquinic acid(m/z 339 [M+H]⁺) and 5-O-caffeoylquinic acid methyl ester(m/z 369 [M+H]⁺) were newly confirmed from the lettuce samples. In total content of phenolic compounds, 4 red lettuce samples(2,947.7~7,535.6 mg/100 g, dry weight) showed higher than green lettuce(2,687.3 mg) and head lettuce(320.1 mg).

• 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.9 no.1
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• pp.7-9
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• 2003

The antioxidative constituents isolated from Hedyotis diffusa were identified as quercetin 3-O-${\beta}$-rutinoside (1) and quercetin 3-O-${\beta}$-glucoside (2). We also isolated asperuloside (3) from this plant. Identification was done based on spectroscopic analysis. Quercetin 3-O-${\beta}$-rutinoside was the stronger antioxidant than quercetin 3-O-${\beta}$-glycoside while asperuloside was inactive.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.104-113
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• 2017

Anthocyanins contained in Rhododendron schlippenbachii (royal azalea) are expressed in a variety of colors and affect flower colors. R. schlippenbachii flowers of seven colors (white, red group: pink, deep pink, red, purple group: light purple, purple, deep purple) were collected from the garden around KT&G building in the college of agriculture and life science. Seven types of anthocyanins [cyanidin 3-O-diglucoside, cyanidin 3-O-arabinoside-5-O-glucoside, cyanidin 3-O-galactoside, peonidin 3-O-arabinoside-5-O-glucoside, cyanidin 3-O-glucoside, cyanidin 3-O-(6"-O-malonyl) arabinoside, cyanidin 3-O-(6"-O-coumaroyl) glucoside] turned out to be from the cyanidin and peonidin series in R. schlippenbachii flowers. Also, seven types of flavonols [azaleatin 3-O-glucoside, azaleatin 3-O-arabinoside, azaleatin 3-O-rhamnoside, quercetin 3-O-galacatoside, quercetin 3-O-glucoside, quercetin 3-O-arabinoside, quercetin 3-O-rhamnoside] were identified in R. schlippenbachii flowers. Total anthocyanin amounts decreased in R. schlippenbachii flowers in the following order: 'deep pink' (8.07) > 'red' (6.37) > 'pink' (5.35) > 'deep purple' (0.78) > 'purple' (0.43) > 'light purple' ($0.22mg{\cdot}g^{-1}$ dry weight, DW) > 'white' (not detected). Total flavonol amounts decreased in the following order: 'pink' (97.78) > 'deep pink' (63.79) > 'deep purple' (61.98) > 'white' (57.58) > 'light purple' (47.06) > 'purple' (46.76) > 'red' ($7.60mg{\cdot}g^{-1}$ dry weight, DW). This study provided the quantitative and qualitative information for the variation of anthocyanin and flavonol compounds in R. schlippenbachii flowers. Furthermore, this information can contribute to the identification of anthocyanin and flavonol compounds in other Rhododendron flowers.

• 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.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.105-108
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• 2000

Impatiens textori Miquel (Balsaminaceae) is an annual plant growing in most parts of Korea. The herb of this plant has been used for the external application of snake poison and the bruise. Previous investigations conducted with the herbs have demonstrated it to contain three flavones and three flavone glycosides. Continuing to previous reports, quercetin, kaempferol and acacetin $7-O-{\beta}-D-glucoside$ were isolated from the herbs of this plant.