• Korean Journal of Plant Taxonomy
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• v.41 no.1
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• pp.10-15
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• 2011

Fifteen populations comprising three taxa and a putative hybrid of Fallopia sect. Reynoutria in Korea were examined for their leaf flavonoid constituents. Nineteen flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols quercetin and kaempferol, and of the flavones apigenin and luteolin. Among them, quercetin 3-O-galactoside and quercetin 3-O-glucoside were major flavonoid constituents, and present in all taxa. The flavonoid data appear to be very useful for taxon delimitation, and all taxa examined are readily distinguished by their flavonoid profiles. In addition, the flavonoid data suggest that the Nonsan population may be of hybrid origin involving F. japonica var. japonica, F. forbesii, and F. sachalinensis. In F. japonica var. japonica, there is no apparent correlation between their levels of polyploidy and flavonoid chemistry, but geographical variation of the flavonoid profiles among some populations was detected.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.288-294
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• 2005

Flavonoid compounds show several biological activities and generally exist in the forms of glycones linking sugar moiety to main structure. Flavonoid glycones such as naringin and hesperidin in korean citrus peel are slower absorbed and consequently less active than their aglycone, naringenin and hesperetin, respectively. Therefare to increase the content of flavonoid aglycone in korean citrus peel, we used commercial carbohydrate-hydrolysing enzymes, AMG 300 L, Pectinex 100 L, and Viscozyme for transforming flavonoid glycones to aglycones. Optimal conditions of enzyme reaction were pH 5.0-7.0, $5\%$ enzyme, and 24-48 hrs. The content of naringenin and hesperetin as flavonoid aglycones in untreated citrus peel is $100\~200\;ng/g$ of dried citrus peel. In case of enzyme-treated citrus peel the content of naringenin and hesperetin increased to $1,539\∼6,674\;ng/g\;and\;1,974\∼8,906\;ng/g$ of dried citrus peel, respectively. Finally the content of flavonoid aglycones could be extracted to 10-80 times. Now enzyme-treated citrus peel may be applied to use for functional food because of its higher flavonoid aglycones as more active compounds.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.197-201
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• 2020

In order to enhance the extraction efficiency of flavonoid from Saururus chinensis, carbohydrate-hydrolyzing enzyme Viscozyme L aided extraction techniques have been studied. Then flavonoid composition, as well as quercetin, were also identified using UV/Vis, HPLC/MS, and ¹H-NMR. The results showed that favorable extraction conditions were Viscozyme L concentration of 0.25 mg/g, pH 4.2, reaction at 45 ℃ for 12 h. Under the favorable extraction condition, total flavonoid yield (37.9 mg/g) and quercetin yield (0.86 mg/g) increased by about 2.0 and 9.6 times, respectively, compared to control group. Interestingly, as a significant flavonoid of S. chinensis, flavonoid glycones rutin was hydrolyzed to aglycones quercetin by Viscozyme L. These findings provide scientific and theoretical support for the development quercetin-rich products, which was quickly absorbed by the human body than rutin.

• Journal of Nutrition and Health
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• v.45 no.3
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• pp.283-292
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• 2012

Flavonoids have been hypothesized to reduce the risk of chronic diseases, but the lack of a flavonoid database hampered epidemiological studies addressing this issue in Korea. In this study, we developed a flavonoid database, based on a systematic review. A total of 1549 food items containing flavonoids were selected using the Korean Nutrient Database. Among them, flavonoid contents for only 649 food items were evaluated with analytical values and the remaining 900 items were replaced with adaptations or calculations from similar items. The developed flavonoid database covered 93.2% of fruits and fruit juices, 76.1% of vegetables, 98.4% of legumes and legume products, and 85.0% of all plant foods overall (1,549 items) as reported by the 24-hr dietary recall method regarding the 2008 Korean National Health and Nutrition Examination Survey. We found that this flavonoid database, overall, included 95.6% of all mainly consumed plant foods by Koreans. This flavonoid database is expected to be useful in regards to the correlation study of flavonoid intake and chronic diseases.

• 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.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.263-270
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• 2016

This study investigated the phenolic, flavonoid, and vitamin constituents in the main root, root hair, and leaf of ginseng. The total individual phenolic and flavonoid contents were the highest in the leaf, followed by the main root and root hair. Ferulic acid and m-coumaric acid were found to be the major phenolics in the main root and root hair, while p-coumaric acid and m-coumaric acid were the major phenolics in the leaf. Catechin was the major flavonoid component in the main root and root hair, while catechin and kaempferol were the major flavonoid components in the leaf. Pantothenic acid was detected in the highest quantity in the non-leaf parts of ginseng, followed by thiamine and cobalamin. Linolenic acid and menadione were the major components in all parts of ginseng.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.265-275
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• 2002

Flavonoid biosynthesis is one of the most extensively studied areas in the secondary metabolism. Due to the study of flavonoid metabolism in diverse plant system, the pathways become the best characterized secondary metabolites and can be excellent targets for metabolic engineering. These flavonoid-derived secondary metabolites have been considerably divergent functional roles: floral pigment, anticancer, antiviral, antitoxin, and hepatoprotective. Three species have been significant for elucidating the flavonoid metabolism and isolating the genes controlling the flavonoid genes: maize (Zea mays), snapdragon (Antirrhinum majus) and petunia (Prtunia hybrida). Recently, many genes involved in biosynthesis of flavonoid have been isolated and characterized using mutation and recombinant DNA technologies including transposon tagging and T-DNA tagging which are novel approaches for the discovery of uncharacterized genes. Metabolic engineering of flavonoid biosynthesis was approached by sense or antisense manipulation of the genes related with flavonoid pathway, or by modified expression of regulatory genes. So, the use of a variety of experimental tools and metabolic engineering facilitated the characterization of the flavonoid metabolism. Here we review recent progresses in flavonoid metabolism: confirmation of genes, metabolic engineering, and applications in the industrial use.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.7-16
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• 2017

BACKGROUND: Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea. METHODS AND RESULTS: To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processing methods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This finding was more pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreased with increasing treatment time. Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111. CONCLUSION: The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at $90^{\circ}C$ for 5 min, and roasting.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.578-581
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• 1995

The seasonal variation of two flavonoid, quercitrin and afzelin, in the leaves of Cedrela sinensis A. Juss. from May until November was investigated by high performance liquid chromatography. Separation by reversed phase chromatography on ${\mu}-Bondapak\;C_{18}$ column was achieved by isocratic elution. The concentration of quercitrin was 5.81% (w/w) in May and high in July(8.89%, w/w), August(7.94%, w/w), and decreased from September to November. The content of another flavonoid, afzelin was 0.06% (w/w) in May and highest in June (0.12%, w/w), and was reduced from July.