• YAKHAK HOEJI
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• v.44 no.2
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• pp.119-127
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• 2000

This paper describes isolation and elucidation structure of the components from leaves and evaluate the radical scavenging activity on DPPH radical for antioxidant effect. Bioassay guided fractionation of MeOH extract afforded active EtOAc and BuOH factions. The most active EtOAc fraction was repeatedly chrormatographed over silica and Sephadex LH-20 to afford six flavonoid compounds. Studies on the antioxidant activity of these constituents showed that quercetin was the most active of these compounds. Luteolin and kaempherol are also active, These results suggested that the antioxidant activity of leaves of Angelica gigas may be due to flavonoid components. All the compounds were identified by spectroscopic methods and are the first report from leaves of Angelica gigas.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4352-4360
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• 2011

A four dimensional quantitative structure activity relationship analysis was applied to a series of 50 flavonoid inhibitors of $p56^{lck}$ protein tyrosine kinase by the molecular comparative electron topological method. It was found that the -log (IC50) values of the compounds were highly dependent on the topology, size and electrostatic character of the substituents at seven positions of the flavonoid scaffold in this study. Depending on the negative or positive charge of the groups correctly embedded in these substituents, three-dimensional bio-structure to increase or decrease -log (IC50) values in the training set of 39 compounds was predicted. The test set of 11 compounds was used to evaluate the predictivity of the model. To generate 4D-QSAR model, the defined function groups and pharmacophore used as topological descriptors in the calculation of activity were of sufficient statistical quality ($R^2$ = 0.72 and $Q^2$ = 0.69). Ligand docking approach by using Dock 6.0. These compounds include many flavonoid analogs, They were docked onto human families of p56lck PTKs retrieved from the Protein Data Bank, 1lkl.pdb.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.667-671
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• 2003

The total phenolic and flavonoid contents of Lentinus edodes extracts were determinated by spectrophotometrical .method, and antihepatotoxic activity was detected on glutathione S-Transferases(GST). The total phenolic contents was highest water extract than solvent(ethanol, methanol) extracts, but flavonoid content was appear on opposite. GST activity was the highest appears in water extract. This fact verified of anticancer effect indirectly of Lentinus edodes.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.145-161
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• 2015

This research was conducted in order to understand the hybridization between Quercus aliena Blume and Q. serrata Murray in Korea which show wide range of morphological variations within species and interspecific variations of diverse overlapping characteristics caused by hybridization. Morphological analysis (principal components analysis; PCA) of 116 individuals representing two species and their intermediates were performed. As a result, two species were clearly distinguished in terms of morphology, and intermediate morpho-types assumed to be hybrids between the two species were mostly located in the middle of each parent species in the plot of the principal components analysis. There was a clear distinction between two species in trichome distribution pattern which is an important diagnostic character in taxonomy of genus Quercus, whereas intermediate morpho-types showed intermediate state between two species' trichome distributions. Forty-two individuals representing two species and their intermediates were examined for leaf flavonoid constituents. Twenty-three flavonoid compounds were isolated and identified: They were glycosylated derivatives of flavonols, kaempferol, quercetin, isorhamnetin and myricetin. The flavonoid constituents of Q. aliena were five glycosylated derivatives: kaempferol 3-O-galactoside, kaempferol 3-O-glucoside, quercetin 3-O-galactoside, quercetin 3-O-glucoside, and Isorhamnetin 3-O-glucoside. The flavonoid constituents of Q. serrata had 20 diverse flavonol compounds including five flavonoid compounds found in Q. aliena. It was found that there is a clear difference in flavonoid constituents of Q. aliena and Q. serrata. Flavonoid chemistry is very useful in recognizing each species and putative hybrids. The flavonoid constituents of intermediates were a mixture of the two species' constituents and they generally showed similar characteristics to morpho-types. The hybrids between Q. aliena and Q. serrata showed morphologically and chemically diverse characteristics and it is assumed that there are frequent interspecific hybridization and introgression.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6991-6995
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• 2013

Antioxidant activity, total phenolic, total flavonoid compounds and cytotoxicity to cancer cell lines of propolis extracts from two extraction methods were investigated in this study. Propolis was collected from Phayao province and extracted with 70% ethanol using maceration and sonication techniques. The antioxidant activity was evaluated by DPPH assay. Total phenolic and flavonoid compounds were also determined. Moreover, the cytotoxicity of propolis was evaluated using MTT assay. The percentage propolis yield after extraction using maceration (18.1%) was higher than using sonication (15.7%). Nevertheless, antioxidant and flavonoid compounds of the sonication propolis extract were significant greater than using maceration. Propolis extract from sonication showed antioxidant activity by $3.30{\pm}0.15$ mg gallic acid equivalents/g extract. Total phenolic compound was $18.3{\pm}3.30$ mg gallic acid equivalents/g extract and flavonoid compound was $20.49{\pm}0.62$ mg quercetin/g extract. Additionally, propolis extracts from two extraction methods demonstrated the inhibitory effect on proliferation of A549 and HeLa cancer cell lines at 24, 48 and 72 hours in a dose-dependent manner. These results are of interest for the selection of the most appropriate method for preparation of propolis extracts as potential antioxidant and anticancer agents.

• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.205-212
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• 2014

BACKGROUND: This study focused on the contents of flavonoid compounds in vegetables. Generally vegetables have contributed to a healthy diet, arisen from contains a large amount of fiber and functional ingredients. And flavonoid compounds are one of major functional components in the vegetables. currently research of flavonoid contents does not enough, specially in the part of homegrown vegetable. METHODS AND RESULTS: Vegetable samples were purchased in domestic market. Sample extraction by methanol, distilled water, and formic acid based solvent. Also same solvent used for mobile phase in UPLC. Eleven types of flavonoid compounds were analyzed with same kind of external standard and one kind of internal standard (galangin) for quantification. Standard calibration curve presented linearity with the correlation coefficient $R^2$ > 0.98, analysed from 1 to 50 ppm concentration. The quantitative value and multivariate analysis results were derived from the Excel and SIMCA-P11. Overall, onion has largest amount(916.5 mg/100 g) of flavonoid and also other vegetables have has significant amount[Mugwort: 138.8, Galic stem:123.6 mg/100 g etc.] of flavonoid compounds. Edible portion of vegetables per share for simulating by SIMCA-P11, root vegetables has had difference with other vegetables according to distributions and amounts of flavonoid compounds. CONCLUSION: Optionally, the results from this experiment can use to select the material for flavonoid researches. And based on these results, if this experiment will be continuously complemented, and performed, could used in various fields.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.170-176
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• 2008

The quantitative structure-activity relationship (QSAR) of a set of 35 flavonoid compounds presenting antioxidant activity was established by means of Genetic Algorithm-Multiple Linear Regression (GA-MLR) technique. Four-parametric models for two sets of data, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity $(R^2=0.788,\;Q^2_{cv}=0.699\;and\;Q^2_{ext}=0.577)$ and scavenging activity of reactive oxgen species (ROS) induced by $H_2O_2 (R^=0.829,\;Q^2_{cv}=0.754\;and\;Q^2_{ext}=0.573)$ were obtained with low external predictive ability on a mass basis, respectively. Each model gave some different mechanistic aspects of the flavonoid compounds tested in terms of the radical scavenging activity. Topological charge, H-bonding complex and deprotonation processes were likely to be involved in the radical scavenging activity.

• Journal of Plant Biology
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• v.36 no.3
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• pp.297-300
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• 1993

Six flavonoid compounds from the ethyl acetate fraction of Machilus thunbergii leaves were identified by HPLC. Separation by reversed phase chromatography on u-Bondapak C18 column was achieved by isocratic elution. The contents of the major flavonoids, guaijaverin and quercitrin were about 0.48% (w/w) and 0.98% (w/w) for the methanol extract, respectively.

• Natural Product Sciences
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• v.27 no.4
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• pp.234-239
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• 2021

Masclura tricuspidata, also called as Cudrania tricuspidata, is one of the most common Moraceae family plants in East Asia. Its trivial name follows mulberry due to the similar morphology. Investigation of the bioactive constituents of M. tricuspidata leaves yielded a new xanthone derivative along with twenty known compounds through various chromatographic techniques. A new compound was defined as mascluraxanthone (3), a prenylated xanthone glucoside on the basis of 1D and 2D NMR and MS data. Twenty known compounds were identified as four xanthone derivatives (1-2 and 4-5), two flavans (6-7), six flavanol derivatives (8-13), a flavonone (14) and seven flavonol derivatives (15-21). Among the isolated compounds, flavanol and flavonoid derivatives with 3',4'-OH groups showed antioxidant and anti-tyrosinase activities. Conclusively, the leaves of M. tricuspidata are rich in aromatic compounds including xanthones and flavonoids. In addition, these constituents showed antioxidant and anti-tyrosinase potentials, which might be useful for oxidative stress related diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.353-358
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• 2006

Flavonoid and limonoid compounds were determined by HPLC on the methanol and ethanol extracts from citron seeds. The quantities of the compounds in these categories were higher in the ethanol extract than methanol extract. The types of these compounds were detected in larger numbers in the ethanol extract. The content of limonin was the largest in both methanol and ethanol extract among the detectable compounds ; 140.34 mg/100g and 170.98 mg/100g, respectively, and the contents of other compounds, caffeic acid, naringin, lutin, nomilin, were found in large amount in this order. The molecular weights of forty two compounds in ethanol extract were determined with mass spectrums and extracted ion current chromatograms by HPLC/MS.