• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3447-3452
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• 2014

Detailed chemical investigation of Boscia senegalensis (Per) Lam. ex Poir. led to the isolation of one new flavonol glycoside, rhamnocitrin-3-O-${\beta}$-$\small{D}$-(6"-O-E-feruloyl)-glucopyranoside named bosenegaloside A (1), with seven known compounds, rhamnocitrin-3-O-${\beta}$-$\small{D}$-(6"-O-E-p-coumaroyl)-glucopyranoside (2), rhamnocitrin-3-O-${\beta}$-$\small{D}$-glucopyranoside (3), 3,4,5-trimethoxyphenol-${\beta}$-$\small{D}$-glucopyrinoside (4), lasianthionoside A (5), 3,7-dimethyl-1-octene-3,6,7-triol-6-O-${\beta}$-$\small{D}$-glucopyranoside (6), syringin (7), and austroside B (8). The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of these data with previously published results. The inhibitory activity of the isolated compounds on soluble epoxide hydrolase (sEH) was assessed. Compounds 1-3 potently inhibited sEH activity with $IC_{50}$ values of $12.8{\pm}0.5$, $18.4{\pm}0.2$, and $11.3{\pm}0.9{\mu}M$, respectively.

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.280-282
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• 1992

Quercitrin and hyperin were isolated from the leaves of Kalopanax pictum and these structures were characterized on the basis of chemical and spectral data.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.251-256
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• 2011

The leaves of Hippophae rhamnoides were extracted with methanol and then further fractioned with hexane, ethyl acetate, butanol and water in order to investigate biological activity. Two flavonol glycosides were isolated and identified from ethyl acetate soluble fraction, which showed the strongest antioxidant activity ($RC_{50}$ = 4.33 ${\mu}g/ml$). Isolated two compounds have shown strong free radical scavenging activity. Especially, quercetin 3-O-glucoside ($RC_{50}$ = 2.60 ${\mu}g/ml$) was more active than ${\alpha}$-tocopherol ($RC_{50}$ = 4.67 ${\mu}g/ml$). Total phenol and flavonoid contents were the highest to 4.17 and 1.14 mg/ml in the ethyl acetate soluble fraction. In addition, ethyl acetate soluble fraction was shown to the strongest ${\alpha}$-glucosidase inhibitory activity ($IC_{50}$ = 137.88 ${\mu}g/ml$) among the fractions. The results suggest that leaves of H. rhamnoides could be a potential source of natural antioxidant.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.320-326
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• 1996

Seven antioxidative flavonoids were isolated from Jindalrae flowers (Rhododendron mnonulatum Turcz.), an edible plant in Korea. These compounds were identified as afzelin, ampelopsin, catechin, myricetin, myricitrin, quercetin and quercitrin on the basis of IR, UV, FAB-MS, $^1H\;NMR,\;and\;^{13}C\;NMR$ data. These compounds were consisted of two flavonols, three flavonol glycosides, a flavane, and a dihydroflavonol. The flavonol glycosides (14.4 g) present in th ethyl ether and ethyl acetate fractions comprised up to 82% of their total flavonoid amount (17.6 g) finally recovered by means of polyamide C-200 column chromatography, preparative TLC, recrystallization, and Sephadex LH-20 column chromatography. The antioxidant activities were measured in an ethanol solution of linoleic acid in the presence of ferric thiocyanate. The antioxidant efficiency increased in the order of afzrlin<$\alpha-tocopherol$

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.1-7
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• 1998

The morphological and chemical characteristics of leaves and fruits were observed in the three mulberry varieties, including Daeryugppong(Morus Lhou(Ser.) koidz), Kugsang 20(Morus Lhou(Ser.) koidz) and Cataneo(Morus alba L.). The leaf development in spring was earliest in Cataneo and latest in Kugsang. Content of total nitrogen and Mg in leaf was the highest in Cataneo while that of P2O5, K and Ca in Daeryukppong. Flowers started to bloom from May 8 and in full bloom around May 15. Mature fruits began to set from June 10 to 15 and lasted by July 10 in Cataneo. Average fruit weight was heaviest in Kugsang 20(3.52 g/fruit), while lowest in Daeryukppong(1.61 g/fruit). In fruits, glucose and fructose were the major sugars. Citric acid was the most abundant organic acid in three varieties with its average content from 0.8 to 0.14%. The major pigment in fruit was anthocyanin and its content varied among varieties. The stability of anthocyanin was evaluated under various pH, temperature, and sugar concentrations. Rutin was the major flavonol glycoside present in fruits and its content varied from 0.92 to 3.36 mg/gDW. Other flavonol glycosides such as isoquercitrin and quercitrin were also detected in fruit.

• Natural Product Sciences
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• v.13 no.3
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• pp.225-228
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• 2007

A new quercetin 3-O-trisaccharide was isolated from the leaves of Rubus crataegifolius (Rosaceae). The structure of this compound was determined as quercetin $3-O-{\alpha}-L-arabinofuranosyl-(1{\rightarrow}2)-{\beta}-D-xylopyranosyl-(1{\rightarrow}2)-{\beta}-D-galactopyranoside$ on the basis of 2D-NMR spectroscopic data. This flavonol glycoside was isolated for the first time from a natural source.

• YAKHAK HOEJI
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• v.35 no.3
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• pp.240-244
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• 1991

A new lupane triterpenoid saponin, 3, 11-dihydroxy-lupan-20-en-28-oic acid 28-o-$\alpha$-L-rhamnopyranosyl-(1$\rightarrow$4)-$\beta$-D-glucopyranosyl-(1$\rightarrow$6)-B-D-glucopyranosyl ester, have been isolated from the leaves of Acanthopanax koreanum Nakai (Araliaceae) together with one known flavonol glycoside, rutin. The structure were elucidated on the basis of spectral and chemical evidence.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.442-446
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• 2006

Cedrela sinensis is a broadleaf tree that is widely cultivated in Korea and China. It was used for treating enteritis, dysentery, and skin itch in oriental medicine. In this study, three major flavonoids, kaempferol-3-O-rhamnoside (1), quercetin-3-O-rhamnoside (2), and quercetin-3-O-glucoside (3), were isolated from the leaf of Cedrela sinensis. The biological activities of these compounds were tested by inhibitory activity of matrix metalloproteinases-2 (Type IV collagenase) method together with a cytotoxicity and a apoptosis test against human cancer cell lines.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.237-244
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• 1998

A study was carried out to elucidate the relation between the production of flavonol glycosides and the change of phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba by the unassisted and synergistic effects of various factors. The quercetin production showed a mixed-growth-associated pattern in cell suspension cultures. Fluorescent light and UV radiation increased phenylalanine ammonia-lyase (PAL) activity, and resulted in the increase of the production of quercetin and kaempferol ten- and four-fold, respectively, as compared to that obtained in the normal culture condition. The cell growth of Ginkgo biloba was enhanced .at higher temperatures whereas the quercetin production was at its maximum at low temperatures. Moreover, the quercetin production was increased by temperature change during the culture period. In particular, the quercetin production was at the highest level when the culture temperature was elevated from $10^{\circ}C\;to\;30^{\circ}C$. The addition of phenylalanine as a precursor in the culture medium stimulated an 8-fold increase in the production of quercetin; the addition of naringenin caused a l0-fold increase. The quercetin production was also greatly increased by feeding enzyme cofactors such as 2-ketoglutarate and ascorbic acid in the culture medium, but specific PAL activity was not increased except with phenylalanine feeding. The synergistic effect of UV radiation and naringenin feeding was observed, resulting in the increase of flavonol glycoside production at a rate higher than in any other case investigated.

• Korean Journal of Pharmacognosy
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• v.22 no.2
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• pp.85-90
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• 1991

The seasonal variation of two flavonol glycosides, icariin and epimedoside A, in the aerial parts and underground parts of Epimedium koreanum from June through September was investigated. The icariin concentration was decreased with time in both parts. Epimedoside A concentration was fluctuated, being highest in June and lowest in July in the underground parts. In the aerial parts, however, it was almost same in concentration. Determinations were made of the occurrence of two new flavonol glycosides, 2‘-O-rbamnosyl ikarisoside A and 2’-O-rhamnosyl icarisid II in the aerial parts and their changes in concentration were similar to those in the underground parts, being highest in July in both parts.