• Journal of Microbiology and Biotechnology
• /
• v.9 no.5
• /
• pp.661-667
• /
• 1999

The effect of fungal elicitor and heavy metal salts on the production of flavonol glycosides in cell cultures of Ginkgo biloba was investigated. Among the fungi tested, Trichoderma longibrachiatum ATCC 52326 was found to be the most efficient in the production of flavonol glycosides. Kaempferol production from the elicited callus increased ten-fold as compared to the unelicited callus, while quercetin concentration of elicited cells was nine-fold higher than that of uneliceited cells in suspension cultures. The maximum quercetin concentration of 0.362㎎/l was obtained in 1.25㎎/l of the homogenate elicitor. Among the heavy metal salts tested, CuSO₄ showed a significant effect on quercetin accumulation, reaching to the concentration of 0.526 ㎎/l. Quercetin concentration increased to a maximum of l2-fold in response to CuSO₄ treatment as compared to that of untreated cells. The phenylalanine ammonia-lyase (PAL) activity and flavonol glycosides production simultaneously increased for 5 days of culture after fungal elicitor feeding, and their contents showed the same proportional patterns during the culture period. In contrast, PAL activity of cell cultures treated with CuSO₄ was almost constant during the culture period, although quercetin production increased remarkably.

• Applied Biological Chemistry
• /
• v.39 no.4
• /
• pp.320-326
• /
• 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<$\alpha-tocopherol$

• Natural Product Sciences
• /
• v.14 no.2
• /
• pp.86-89
• /
• 2008

Phytochemical study of the aerial parts of Lotus lalambensis Schweinf resulted in the isolation and identification of two new flavonol glycosides; kaempferol $3-O-(5"-acetyl)-apioside-7-O-{\alpha}-L-rhamnopyranoside$ (1) and kaempferol $3-O-{\alpha}-[{\beta}-D-xylosyl-(1""{\rightarrow} 2")-L-rhamnopyranoside]-7-O-{\alpha}-L-rhamnopyranoside$ (2). Structures were determined utilizing different physical, chemical, spectroscopic data including 2D-NMR experiments and HRFABMS.

• Natural Product Sciences
• /
• v.24 no.3
• /
• pp.155-158
• /
• 2018

A new flavonol derivative, meliglabrin (1) along with three known flavonols, ternatin (2), meliternatin (3), and 5,4'-dihydroxy-3,7,3'-trimethoxyflavon (4) were isolated from the leaves of Melicope glabra (Blume) T.G. Hartley. Their structures were determined using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1 - 4 were evaluated for their cytotoxicity against murine leukemia P-388 cells, compound 4 showed moderate activity.

• Natural Product Sciences
• /
• v.8 no.3
• /
• pp.77-82
• /
• 2002

An investigation of the methanolic extract of Maesa lanceolata leaves has led to the isolation of four novel flavonol glycosides characterised as myricetin 3-0-2', 3', 4'-triacetylxylopyranoside (1), quercetin $3-O-{\beta}-3'$, $6'-diacetylglucopyranosyl-(1{\longrightarrow}4)-{\alpha}-2'$, 3'-diacetylrhamnopyranoside (2), myricetin $3-O-xylopyranosyl-(1{\to}3)-{\alpha}-rhamnopyranoside$ (3) and quercetin $3-O-{\beta}-ga1actopyranosyl-(1{\to}4)-{\alpha}-rhamnopyranoside-7-O-{\beta}-galactopyranoside$ (4). Also isolated from the same extract were known flavonols; quercetin (5), myricetin (6), quercetin 3-O-xylopyranoside (7), quercetin $3-O-{\alpha}-rhamnopyranoside$ (8), myricetin $3-O-{\alpha}-rhamnopyranoside$ (9), myricetin $3-O-{\beta}-galactopyranoside$ (10) and quercetin 3-O-rutinoside (11).

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

• YAKHAK HOEJI
• /
• v.43 no.1
• /
• pp.5-10
• /
• 1999

As one of the serial studies on the specific and indigenous plants of Mt. Chiri the constituents of aerial part from filipendula formosa (Rosaceae) were investigated. From of the MeOH extract, five flavonol glycosides, kaempferol-3-O-$\beta$-D-galactopyranoside, querecetin-3-O-$\beta$-D-galactopyranoside, quercetin-3-O-$\alpha$-Lrhamopyranosyl (1 6)-$\beta$-D-galactopyranoside, kaempferol-3-O-$\alpha$-L-rhamnopyranosyl (1 6)-$\beta$-D-galactopyranoside and quercetin-7-O-$\beta$-D-glucopyranosy-3-O-$\beta$-D-galactopyranoside were isolated by column chromatographic separation using Amberlite XAD-2 and Sephadex LH-20, and identified physicochemical evidences (IR, FAB-Mass, $^1H,{\;}^{13}C-NMR$).

• Korean Journal of Plant Resources
• /
• v.21 no.5
• /
• pp.395-401
• /
• 2008

Flavonoids are ubiquitous substances in fruits and vegetables. A main subgroup of the flavonoids are the flavonols, of which quercetin and kaempferol are the major representatives in foods. They are used in food supplements at high doses, because of their preventive effects on degenerative diseases. The aim of this study was to determine the combined and separate effects of kaempferol and quercetin on oxidative stress in cow pulmonary artery endothelium (CPAE) cells over a broad concentration range. The results demonstrate that cell viability was greatly increased in kaempferol and quercetin treated cells whether $H_{2}O_{2}$-treated or not. Cell viability also increased when treated with flavonols in the absence of oxidative stress. Both preincubation and simultaneous incubation with kaempferol and quercetin protected against the loss of cell viability induced by 1mM $H_{2}O_{2}(5h)$. Protective effects of flavonols against oxidative stress were shown to depend on the treated flavonol concentrations. No protective effect was shown under low concentration treatment and cell viability increased 1.6 times at $200{\mu}M$ relative to the control group. At the highest flavonol concentration of $300{\mu}M$, the increased cell viability by flavonol treatment was decreased to almost half of the maximum values. Combined treatments with kaempferol and quercetin showed more protective effects against oxidative stress by $H_{2}O_{2}$ than the separate effects of each flavonol. In conclusion, the protective effect of kaempferol and quercetin against oxidative stress was very pronounced but high concentrations of flavonols can also induce cell cytotoxicity.

• Korean Journal of Pharmacognosy
• /
• v.21 no.1
• /
• pp.60-63
• /
• 1990

From the leaves of Machilus thunbergii Sieb. et Zucc. (Lauraceae) afzelin, guaiyaverin and rutin were isolated and identified by chemical and spectral analysis.

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