• Natural Product Sciences
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• v.14 no.2
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• pp.86-89
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• 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
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• v.8 no.3
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• pp.77-82
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• 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 CROP SCIENCE
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• v.59 no.3
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• pp.385-389
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• 2014

Flavonols as a major kind of plant secondary metabolites are known for health-promoting compounds in onions (Allium cepa L.). The objectives of this study are to determine profiles of flavonol glycosides in different 75 onion accessions. A total of five flavonols (quercetin 3,4'-diglucoside, Q34'diG; quercetin 3-glucoside, Q3G; quercetin 4'-glucoside, Q4'G; isorhamnetin 4'-glucoside, I4'G; quercetin, Q) were identified from onion accessions. In positive ion mode using LC-ESI-MS, individual flavonols were confirmed from one and two glycosylation binding with aglycone such as quercetin and isorhamnetin. Total flavonol contents were distributed in white onion (range of 0.18-6.47 mg/g DW) and purple onion accessions (range of 2.39-6.47 mg/g), respectively. The mean of flavonol contents in purple onion (4.41 mg/g) showed 1.4-fold higher than white onion (3.23 mg/g). The Q34'diG and Q4'G were considered as the major compounds of flavonol glycosides in onion accessions.

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

• Preventive Nutrition and Food Science
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• v.15 no.1
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• pp.36-43
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• 2010

The purpose of this study was to investigate the phenolic acid, proanthocyanidin (PAs), and flavonol glycoside contents, as well as the antioxidant activities of pine needle extracts from six species of young pine trees. The extracts were prepared from Section Pinus (Diploxylon): P. densiflora, P. sylvestris, P. pinaster and P. pinea, and Section Strobus (Haploxylon): P. koraiensis and P. strobus. Phenolics were extracted from pine needles with 80% acetone to obtain the soluble free fraction, and insoluble residues were digested with 4 M NaOH to obtain bound ethyl acetate and bound water fractions. Phenolics were analyzed by HPLC, and the hydrophilic antioxidant activity was measured using oxygen radical absorbance capacity (ORAC). Total phenolic and flavonoid contents of the soluble free fraction were higher than those of the bound ethyl acetate and bound water fractions. The main phenolics were monomers and polymers of PAs in the soluble free fraction, and phenolic acids and flavonol glycosides in bound ethyl acetate fraction. Flavonol glycosides found in different species of pine needles were qualitatively similar within fractions, but composition varied among Pinus sections. High levels of kaempferol arabinoside and an unknown compound were present in all Strobus species. The soluble free fraction had the highest antioxidant activity, followed by bound ethyl acetate and bound water fractions.

• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.148-152
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• 1990

Seven flavonol glycosides from the EtOAc fraction of Ginkgo biloba leaves were identified by high performance liquid chromatography. Separation by reversed phase chromatography on $Lichrosorb^{\circledR}$ RP-18 column was achieved by isocratic elution. The content of the major acylated flavonol glycoside, kaempferol 3-0-[$6'-O-{p}-coumaroyl-{\beta}-_D-glucosyl(1{\rightarrow}2)-{\alpha}-_L-rhamnoside$] was about 8.0% and 0.55% for EtOAc fraction and MeOH extract, respectively.

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

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

• 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.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.791-798
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• 2005

The hepatoprotective activity of flavonol glycosides rich fraction (F-2), prepared from 70% alcohol extract of the aerial parts of V calcarata Desf., was evaluated in a rat model with a liver injury induced by daily oral administration of $CCl_4$ (100 mg/kg, b.w) for four weeks. Treatment of the animals with F-2 using a dose of (25 mg/kg, b.w) during the induction of hepatic damage by $CCl_4$ significantly reduced the indices of liver injuries. The hepatoprotective effects of F-2 significantly reduced the elevated levels of the following serum enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant activity of F-2 markedly ameliorated the antioxidant parameters including glutathione (GSH) content, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), plasma catalase (CAT) and packed erythrocytes glucose-6-phosphate dehydrogenase (G6PDH) to be comparable with normal control levels. In addition, it normalized liver malondialdehyde (MDA) levels and creatinine concentration. Chromatographic purification of F-2 resulted in the isolation of two flavonol glycosides that rarely occur in the plant kingdom, identified as quercetin-3,5-di-O-$\beta$-D-diglucoside (5) and kaempferol-3,5-di-O-$\beta$-D-diglucoside (4) in addition to the three known compounds identified as quercetin-3-O-$\alpha$-L-rhamnosyl- (${\rightarrow}6$)-$\beta$-D-glucoside [rutin, 3], quercetin-3-O-$\beta$-D-glucoside [isoquercitrin, 2] and kaempferol-3-O-$\beta$-D-glucoside [astragalin, 1]. These compounds were identified based on interpretation of their physical, chemical, and spectral data. Moreover, the spectrophotometric estimation of the flavonoids content revealed that the aerial parts of the plant contain an appreciable amount of flavonoids (0.89%) calculated as rutin. The data obtained from this study revealed that the flavonol glycosides of F-2 protect the rat liver from hepatic damage induced by $CCl_4$ through inhibition of lipid peroxidation caused by $CCl_4$ reactive free radicals.

• Natural Product Sciences
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• v.3 no.1
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• pp.8-10
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• 1997

A new flavonol glycoside, quercetin 3-rhamnosyl $(1{\rightarrow}3)$ galactoside [5] was isolated from the leaves of M. africana. The known compounds kaempferol 3-rutinoside [1], 3'-O-methylquercetin 3-rutinoside [2], quercetin 3-rutinoside [3], and quercetin 3-rhamnosyl $(1{\rightarrow}6)$ galactoside [4] were also isolated for the first time from this plant. Their structures were determined by chemical and spectroscopic methods.