• 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.

• Natural Product Sciences
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• v.24 no.3
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• pp.213-218
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• 2018

Chemical investigation of the plant Tristemma hirtum P. Beauv (Melastomataceae) resulted to the isolation of a new flavonol glycoside named quercetin-7-O-${\alpha}$-D-arabinofuranoside (1), together with nine known compounds including 3'-hexadecanoyl-2'-(9aZ)-tetradecanoyl-glycerol 1'-O-[${\beta}$-D-galactopyranosyl-(1'' ${\rightarrow}$ 6'')-${\alpha}$-D-galactopyranoside] (2), arjunolic acid (3), ${\beta}$-sitosterol-3-O-${\beta}$-D-glucopyranoside (4), terminolic acid (5), quercetin (6), asiatic acid (7), maslinic acid (8), $1{\beta}$-O-galloylpedunculagin (9) and 6-hydroxyapigenin 7-O-${\beta}$-D-glucopyranoside (10) from the methanol extract using normal and reversed phase column chromatography. The structures of these compounds were determined by comprehensive interpretation of their spectral data mainly including 1D- 2D-NMR ($^1H-^1H$ COSY, HSQC, and HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis.

• Natural Product Sciences
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• v.14 no.4
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• pp.233-238
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• 2008

The aerial parts of Epimedium koreanum Nakai have been used to stimulate hormone secretion in treating impotence. Ten flavonol glycosides, 3,4,5-trihydroxy-8-prenylflavone 7-O-[${\beta}$-D-glucopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranoside] (1), hyperoside (2), icarisid II (3), 2"-O-Rhamnosylicarisid II (4), epimedin A (5), epimedin B (6), epimedin C (7), icariin (8), hexandraside E (9), and epimedoside A (10) were isolated from the an ethylacetate soluble extracts of the aerial parts of Epimedium koreanum Nakai through activity-monitord fractionation and isolation method. The structures of compounds 1 - 10 were elucidated by high resolution fast atom bombardment mass spectrometry and two dimentional nuclear magnetic resonance spectroscopy analysis. Compounds 1 and 4 showed potent antioxidant activity, with $IC_{50}$ values of 19.7 and 11.5 ${\mu}g$/mL and 88.2 and 90.5 ${\mu}M$, respectively.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.477-483
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• 2023

The flowers of Carthamus tinctorius (Safflower) were extracted with 80% aqueous methanol (CTex) and the concentrates were partitioned into EtOAc (CTE), n-BuOH (CTB), and H₂O (CTW) fractions. Repeated silica gel (SiO₂) and octadecyl silica gel column chromatographies for the EtOAc and n-BuOH fractions led to isolation of four flavonol glycosides. Nuclear magnetic resornance, infrarad spectroscopy, and mass spectroscopy revealed the chemical structure of the isolated compounds, astragalin (1), isoquercetin (2), nicotiflorin (3), and rutin (4). Quantitative analysis of four isolated compounds in CTex was performed by HPLC. CTex was found to contain 1 at 0.107, 2 at 0.367, 3 at 6.752, and 4 at 0.991 mg/g, respectively. Through this study, an experiment was conducted to evaluate the protective effect on pancreatic islets of the extract, solvent fractions, and all isolated compounds using a zebrafish larvae damaged by alloxan. Pancreatic islet size treated with EtOAc (CTE), n-BuOH (CTB), and H₂O (CTW) fractions and compounds 1-4 significantly increased compared to the alloxan-induced group. These results indicate that C. tinctorius flowers and its isolated compounds are used as potential anti-diabetic agents.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.51-60
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• 2006

Juglans mandshurica barks were collected, extracted with acetone-$H_2O$ (7:3, v/v), fractionated with n -hexane, $CH_2Cl_2$, and EtOAc, and freeze dried to give some dark brown powder. The EtOA cand $H_2O$ soluble fractions were chromatographe d on a Sephadex LH-20 column using $H_2O$-MeOH and EtOH-hexane mixture as eluents. Spectrometric analysis such as NMR and MS, including TLC,were performed to characterize the structures of the isolated compounds. From the EtOAc and $H_2O$ soluble fractions, three flavanols (1~3), three flavonols (4~6) and five flavonol glycosides (7~11) were isolated and elucidated.

• Natural Product Sciences
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• v.24 no.4
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• pp.259-265
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• 2018

The three flavone glycosides, 4'-O-methylisoscutellarein 7-O-(6'''-O-acetyl)-${\beta}$-D-allopyranosyl(1${\rightarrow}$2)-${\beta}$-D-glucopyranoside (1), isoscutellarein 7-O-(6'''-O-acetyl)-${\beta}$-D-allopyranosyl(1${\rightarrow}$2)-${\beta}$-D-glucopyranoside (3), and isoscutellarein 7-O-${\beta}$-D-allopyranosyl(1${\rightarrow}$2)-${\beta}$-D-glucopyranoside (4) in addition to a flavonol glycoside, kaempferol 3-O-${\beta}$-D-glucopyranoside (astragalin, 2), were isolated from Stachys japonica (Lamiaceae). In cholinesterase inhibition assay, compound 1 significantly inhibited aceylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities ($IC_{50}s$, $39.94{\mu}g/ml$ for AChE and $86.98{\mu}g/ml$ for BChE). The content of isolated compounds were evaluated in this plant extract by HPLC analysis. Our experimental results suggest that the flavonoid glycosides of S. japonica could prevent the memory impairment of Alzheimer's disease.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.40-45
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• 2021

Prior studies of physiologically active substances in grapes have focused only on the fruit, pericarp, and branches, as well as the pulp and seeds. The present study assessed the changes in quercetin-3-O-glucuronide (Q3OG) and flavonol glycoside content using grape leaves from Vitis labruscana B. and V. coignetiae at different growth stages and provided basic data for quality control. Content analysis showed that both varieties differed in Q3OG and flavonol glycoside content by growth stage, and the components were found to be high in the order of fruit, maturation, and coloration. Also, Vitis labruscana B. has a better vascular relaxation effect than Vitis coignetiae. These results suggest that in the use of grape leaves as a functional raw material, Q3OG and flavonol glycosides can be used as indicator components. In addition, if raw materials for each growth stage are mixed in a particular ratio, it will be a way to manage the specific efficacy and content of indicator components.

• Korean Journal of Pharmacognosy
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• v.27 no.1
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• pp.80-82
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• 1996

Nucleoside, flavonol glycoside and disaccharide have been isolated from the aerial part of Angelica keiskei Koidz and identified by means of spectral analysis as adenosine, hyperoside and sucrose, respectively.

• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.1-7
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• 1995

The bark of Ulmus parvifolia Jacq. (Ulmaceae) has been used for the treatment of gonorhea, edema, scabies and eczema marginatum. Previous investigations conducted with the heartwood and leaves have demonstrated it to contain sesquiterpenes as well as fat acids from the heartwood and flavonol glycosides from leaves. However, no phytochemical work has been done on the bark parts of this plant. Investigation of the phytochemical constituents in the barks of U. parvifolia has resulted in the isolation of sterols, sterol glucoside and a catechin glycoside, $(+)-catechin\;7-O-{\alpha}-{_L}-rhamnopyranoside$, all of which were isolated for the first time from this plant. Sterols were consisted of the three components, ${\beta}-sitosterol$, stigmasterol and campesterol in a ratio of 92.1:4.1:3.8, and sterol glucoside was identified as ${\beta}-sitosterol\;3-O-{\beta}-{_D}-glucoside$. The structure of the catechin $7-O-{\alpha}-{_L}-rhamnoside$ was established primarily by analysis of $^1H-and$ COSY-45 NMR, HMQC and HMBC and EI mass spectra of the heptaacetate. Especially, HMBC spectrum provides effective way for the determination of the point of attachment of the rhamnosyl group to catechin moiety.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.461-471
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• 2011

This study was carried out to establish an in vitro culture method of callus having a high antioxidant activity from Ginkgo biloba L. Leaf explants were cultured on Murashige and Skoog's medium supplemented with various growth regulators. The explants were incubated in the dark or 3,000 lux cool-white light. Methanol extracts from incubated callus were evaluated for scavenging activity of the free radicals using DPPH. The best callus growth rate was achieved in MS medium combined with 10 ${\mu}M$ NAA and 5 ${\mu}M$ kinetin in the light condition. Total antioxidant activity of cell aggregates in suspension culture [MS medium supplemented with 10 ${\mu}M$ NAA in the light] was up to 80% of ascorbic acid. By means of HPLC analysis, quantification of the quercetin dehydrate and keamperol profiles from suspension callus was compared. Contents of quercetin dehydrate and keamperol from leaf extracts were 0.07 and 2.24 ${\mu}g/20{\mu}l$, and those from callus 0.56 and 0.18 ${\mu}g/20{\mu}l$, respectively.