• 한국식품영양과학회지
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• 제27권4호
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• pp.693-697
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• 1998

The influence of flavonols from onion skin on xanthine oxidase was investigated. Methanol extract was showed 12.8% of yield, 661.3mg% of flavonoids contents and 88.7% of inhibitory effect on xanthine oxidase F1 and F2 fractions were obtained from the methanol extract by ODS and Sephadex LH-20 chromatography. F1 and F2 fractions flavonols(3-OH free) identified by UV/visible spectroscopy. Inhibitory effect of F1 and F2 on xanthine oxidase were increased with increasing concentration. IC50s of F1 and F2 were 0.95$\mu\textrm{g}$ and 0.67$\mu\textrm{g}$, respectively. To confirm the specificity of F1 and F2 against xanthine oxidase, albumin was added to the reaction mixture. The inhibition of F1 and F2 may be due to specific binding to xanthine oxidase. The modes of their inhibitions were of mixed type with respect to xanthine as a substrate.

• Archives of Pharmacal Research
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• 제17권1호
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• pp.31-35
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• 1994

For comparing with flavones/flavonols, isoflavonoids isolated from Pueraria radix and chemically synthesized from biochanin A were evaluated for the antiinflammatory activity using mouse ear edema test, Isoflavonoids such as daildzein and puerarin hsowed the significant antiinflammatory activity at a dose of 2 mg/mouse, although their activity was generally less than that of flavones/flavonols. 7-O-Substitution of biochanin A was not facorable for the antiinflammatory activity.

• Natural Product Sciences
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• 제15권2호
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• pp.66-70
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• 2009

Phytochemical investigation of the aerial parts of Conyza discoridis (L.) Desf. resulted in the isolation of the new sesquiterpene dilactone ester vernomenin-6-(2-hydroxymethyl)-acrylate (4) and two known sesquiterpene dilactones vernolepin (1) and vernomenin (3). Two known flavonols, 3-O-methylquercetin (2) and transilin (3-O-methylquercetin 7-O-${\beta}$-D-glucopyranoside) (5), were also identified. The structures were determined utilizing physical, chemical and spectral methods.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.91-92
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• 2001

Flavonols are polyphenolic compounds that are present in dietary plant-based foodstuffs and beverages (e. g. apple, onion, grape fruit, tea) and medicinal plants (e. g. Crategus, Ruta graveolens, Silybum marianum, Fagopyrum species) in high concentrations. They have been reported to exhibit a wide variety of biological effects, including anti-inflammatory, antiviral, antioxidant and free-radical-scavenging activities.(omitted)

• Natural Product Sciences
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• 제10권1호
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• pp.35-39
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• 2004

Aldose reductase (AR), the key enzyme of the polyol pathway, is known to play important roles in the diabetic complications. The inhibitors of AR, therefore, would be potential agents for the prevention of diabetic complications. In order to clarify the structural requirements of flavonoids for aldose reductase inhibitory activity, thirty flavonoids were examined. Among the thirty flavonoids, flavonols such as quercetin (5), reyneutrin (7), quercitrin (9), isoquercitrin (11), and avicularin (14) were found to exhibit much stronger AR inhibition. Lonicerin (10), amentoflavone (27) and sophoraflavanone B (30) were also showed strong inhibitory activity. Especially, quercitrin and reyneutrin exhibited the most inhibitory potency on rat lens (RL) AR. The results suggested that flavonol having the 7-hydroxyl and/or catechol moiety at the B ring exhibit strong activity. In addition, flavonols having 3-O-monosaccharide also showed stronger inhibition than free flavonols at the 3-position. These results suggested that quercitrin and reyneutrin are attributed to be the promising compounds for the prevention and/or treatment of diabetic complications.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.198-198
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• 2004

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.201.1-201.1
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• 2001

• 대한화장품학회지
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• 제15권1호
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• pp.1-36
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• 1989

The protective effects of 24 flavonoids against singlet oxygen - induced photohemolysis of rabbit erythrocytes were investigated and compared with their antioxidant activities. 1. All the flavonoid aglycons investigated besides flavone and 7,8-benzoflavone showed tad dose-dependant Protective effects. Especially galagin showed the most Pronounced effect under the experimental condition. 2. The order of the radical-scavenging activities of flavonoids was as follow (-)-EGCG > flavonols > flavonols > flavones > flavanonols. The radical-scavenging activities of flavonoid glycosides were not different from those of their aglycons. 3. When added after irradiation, flavonoids did not alter the photohemolysis pattern of control. In this study, several antioxidant were found and it was newly found that Photohemolysis experiment is a convenient, reproductive diagnostic method in the screening and researching the compound which has antioxidant activity or protective effect on cell membrane against active oxygen species.

• 한국약용작물학회지
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• 제14권5호
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• pp.311-316
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• 2006

The content of four phonolic acids 1-4, and two flavonol aglycones 14 and 15 from Orostachysjaponicus A. Berger grown under night-break and day-length controlled experiments was estimated and compared with those in wild plants. The amount of the phenolic acids 1-4 and the flavonol aglycones 14 and 15 increased with increasing light irradiation under both the night-break and day-length control conditions. It was disclosed that the cultivation conditions such as the night-break and the day-length control were not adversely affect the production of phenolic acids and flavonols in Orostachys japonicus A. Berger extracts.

• Journal of Applied Biological Chemistry
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• 제51권2호
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.