• Korean Journal of Medicinal Crop Science
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• v.16 no.4
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• pp.231-237
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• 2008

This study was conducted to determine the amount of flavonoids in Salicomia herbacea L. grown by a liquid chromatography / mass spectrometry (LC/MS). The flavonoids-contained quercetin (124.43 ppm), rutin (2.57 ppm), quercetin-3-${\beta}$-glucoside (3992.49 ppm), quercetin-3',4'-glucoside (0.08 ppm) and isorhamnetin (27.81 ppm) were detected in the powder sample. In particular, quercetin-3-${\beta}$-glucoside accounted for more than 99% in hay and 96% in powder. These results suggest that S. herbacea, which is one of halophyte plants, has high functional substances as an antioxidant source.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.815-822
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• 1999

Twenty one flavonoids were isolated from ethyl acetate layer of aqueaus EtOH extracts of Artemisia vulgaris and identified as tricin, jaceosidine, eupafolin, diosmetin, chrysoeriol, homoeriodictyol, isorhamnetin, apigenin, eriodictyol, luteolin, luteolin 7-glucoside, kaempferol 3-glucoside, kaempferol 7-glucoside, kaempferol 3-rhamnoside, kaempferol 3-rutinside, quercetin, quercetin 3-glucoside, quercetin 3-galactoside, quercetrin, quercetin 7-glucoside, rutin, and vietexin. The inhibitory activity for all purified flavonoids were examined against lipid peroxidation in rat liver microsome. All examined flavonoids showed considerable antioxidant activity. Among them, $IC_{50}$ value of apigenin, luteolin, isorhamnetin, quercetin, and eriodictyol were showed higher than that of vitamin E used as positive control. And methoxylated flavonoids, tricin, eupafolin, jaceosidine, diosmetin, and isorhamnetin showed considerable antioxidant activity. Each $IC_{50}$ values were shown at 0.9, 1.0, 1.4, 1.0, and $0.7\;{\mu}g/mL$, respectively.

• 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.

• 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).

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.697-701
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• 1998

Two major flavonoid compounds having inhibition activity of xanthine oxidase from onion skin were separated, isolated and identified by ODS chromatography, Sephadex LH-20 chromatography, UV/visible absorption spectroscopy and FAB Mass. Spectral analyses indicated that $F_1$ was a flavonol having 3,5,7,3'-OH and 4'-glucoside (quercetin 4'-glucoside), and $F_2$ was a flavonol having 3(5),7,3',4'-OH (quercetin). FAB-Mass of fraction $F_1\;and\;F_2$ in positive-ion-mode produced a spectra containing main ions at m/z 465, corresponding to the $(M＋H)^+$ ion of quercetin 4'-glucoside, and m/z 303, corresponding to the $(M＋H)^+$ ion of quercetin. The inhibition mechanisms of $F_1\;and\;F_2$ were a mixture of the uncompetative and non-competative modes, with respect to xanthine as a substrate.

• 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.

• 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).

• Current Research on Agriculture and Life Sciences
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• v.33 no.2
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• pp.69-73
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• 2015

The antioxidant capacities, total phenolic contents (TPC), and total quercetin contents (TQC) of a red (Chenjujuck), a yellow (Sunpower), and a white (Grasier) onion cultivar were determined in this study. Onion was separated into edible portion and dry skin. In the case of edible portion, the yellow onion had the highest antioxidant activity, followed by the red onion. The white onion showed neither antioxidant activity nor quercetin compounds. On the other hand, the dry skin of the red onion showed higher antioxidant activity than yellow onion skin. The white onion skin had slight antioxidant activity, low TPC, and no quercetin compounds. In addition, the flavonoid compounds of the edible portion and dry skins of these colored onions were analyzed by UFLC(ultra-fast liquid chromatography). The major compounds were quercetin 3,4-diglucoside and quercetin 4-glucoside in yellow and red onion edible portion, whereas the major compounds in yellow and red onion skins were quercetin 4-glucoside, quercetin, and quercetin 3,4-diglucoside.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.374-378
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• 1990

From the stem of Prunus davidiana, naringenin and its glucoside, kaempferol and its glucoside, dihydrokaempferol, kaempferide glucoside, hesperetin glucoside, quercetin glucoside, d-catechin and $\beta$-sitosterol glucoside were isolated.

• 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).