• Natural Product Sciences
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• v.13 no.3
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• pp.225-228
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• 2007

A new quercetin 3-O-trisaccharide was isolated from the leaves of Rubus crataegifolius (Rosaceae). The structure of this compound was determined as quercetin $3-O-{\alpha}-L-arabinofuranosyl-(1{\rightarrow}2)-{\beta}-D-xylopyranosyl-(1{\rightarrow}2)-{\beta}-D-galactopyranoside$ on the basis of 2D-NMR spectroscopic data. This flavonol glycoside was isolated for the first time from a natural source.

• Natural Product Sciences
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• v.6 no.2
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• pp.91-95
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• 2000

A phytochemical investigation of the aqueous ethanolic flower extract of Tamarix tetragyna led to the isolation and characterization of the hitherto unknown conjugates, kaempheride 3,7-dipotassium sulphate and kaempferol 3,4'-dipotassium sulphate as well. Twelve known flavonol compounds, including kaempheride 3-potassium sulphate and kaempheride $3-O-{\beta}-glucuronide$ were also isolated and identified. $^1H-\;and\;^{13}C-NMR$ spectra for the known kaempheride derivatives have been recorded and assigned for the first time. Structures of all compounds were established by conventional methods of analysis and confirmed by $^1H-,\;^{13}C-NMR$ and mass spectral analysis.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1295-1299
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• 2010

Recently, recombinant Streptomyces venezuelae has been established as a heterologous host for microbial production of flavanones and stilbenes, a class of plant-specific polyketides. In the present work, we expanded the applicability of the S. venezuelae system to the production of more diverse plant polyketides including flavones and flavonols. A plasmid with the synthetic codon-optimized flavone synthase I gene from Petroselium crispum was introduced to S. venezuelae DHS2001 bearing a deletion of the native pikromycin polyketide synthase gene, and the resulting strain generated flavones from exogenously fed flavanones. In addition, a recombinant S. venezuelae mutant expressing a codon-optimized flavanone $3{\beta}$-hydroxylase gene from Citrus siensis and a flavonol synthase gene from Citrus unshius also successfully produced flavonols.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3859-3862
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• 2013

• BMB Reports
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• v.40 no.6
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• pp.870-874
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• 2007

We cloned a uridine-diphosphate dependent glycosyl-transferase RUGT-10 from Oryza sativa. The recombinant enzyme was expressed by glutathione-S transferase gene fusion system in Escherichia coli. RUGT10 showed different regioselectivity depending on the structures of substrates (e.g. flavanone, flavonol, and flavone). Apparently, flavanone such as naringenin and eriodictyol gave one 7-O-glucoside while flavone and flavonol gave more than two products with preferential glucosylation position of hydroxyl group at C-3 position.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.289-296
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• 1995

For the investigation of medicinal resources the studies were carried out to evaluated the pharmaco-constituents in the Leaves of Parthenocissus tricuspidata(Vitaceae), of which leaves have been used in Korea as folk remedies for the treatments of arthritis, jaundice, toothache, neuralgia, and etc. From 1-butanol fraction of the MeOH extract, Compound I ($C_{21}H_{18}O_{13}$, Quercetin-3-O-$\beta$-D-glucuronopyranoside), Compound II ($C_{21}H_{20}O_{12}$, Quercetin-3-O-$\beta$-D-glucopyranoside) and Compound III ($C_{25}H_{28}O_{12}$, Quercetin-3-O-(6"-n-butyl)-$\beta$-D-glucuronopyranoside) were isolated by column chromatographic separation using Sephadex LH-20 and ODS gel. Their structures were elucidated through instrumental analyses, such as $^{1}H$-NMR, $^{13}C$-NMR, IR, UV, El-Mass, FAB-Mass and GC. Especially compound III was Flavonol glycoside and named parthenosin.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.123-128
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• 1999

Chemical characteristics of mulberry syncarp were investigated six mulberry varieties, including Subongppong, Daeryukppong, Kuksang 20, Chongilppong, Cataneo and a wild variety. Water content of mulberry syncarp was 78.5∼85.0%and sugar degree of Kuksang 20 was the highst among six varieties. Anthocyanin content of Chongilppong mulberry syncarp was 282.42mg% and Kuksang 20 was lower 13% than Chongilppong mulberry fruit. Also Daeryukppong and wild variety were higher 11% respectively. GABA content of wild variety was higher than other varieties. In flavonol glyconsides analysis, rutin content was the highest in Cataneo, isoquercitrin content was in a wild variety, guaijaverin and quercitrin content was the highst in Chongilppong respectively.

• Natural Product Sciences
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• v.4 no.4
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• pp.215-220
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• 1998

A new flavonol $3,5-di-O-KSO_3$:kaempferol 7,4'-dimethyl ether $3,5-O-KSO_3$, was isolated and identified from the flowers of Tamarix amplexicaulis. The known compounds quercetin $3-mono-O-KSO_3$, kaempferol 4'-methyl ether $3-mono-O-KSO_3$, kaempferol 7,4'-dimethyl ether $3-O-KSO_3$, quercetin 7,4'-dimethyl ether $3-mono-O-KSO_3$, kaempferol 3-O-glucuronide and quercetin 3-O-glucuronide were also separated and identified. Structures were established by conventional methods, including electrophoretic analysis, and confirmed by negative FAB-MS, $^1H-\;and\;^{13}C-NMR$.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.516-516
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.999-999
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• 2005