• Journal of Microbiology and Biotechnology
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• 제20권9호
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• pp.1359-1366
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• 2010

A search of the Streptomyces avermitilis genome reveals that its closest homologs are several O-methyltransferases. Among them, one gene (viz., saomt5) was cloned into the pET-15b expression vector by polymerase chain reaction using sequence-specific oligonucleotide primers. Biochemical characterization with the recombinant protein showed that SaOMT5 was S-adenosyl-L-methionine-dependent Omethyltransferase. Several compounds were tested as substrates of SaOMT5. As a result, SaOMT5 catalyzed O-methylation of flavonoids such as 6,7-dihydroxyflavone, 2',3'-dihydroxyflavone, 3',4'-dihydroxyflavone, quercetin, and 7,8-dihydroxyflavone, and phenolic compounds such as caffeic acid and caffeoyl Co-A. These reaction products were analyzed by TLC, HPLC, LC/MS, and NMR spectroscopy. In addition, SaOMT5 could convert phenolic compounds containing ortho-dihydroxy groups into O-methylated compounds, and 6,7-dihydroxyflavone was known to be the best substrate. SaOMT5 converted 6,7-dihydroxyflavone into 6-hydroxy-7-methoxyflavone and 7-hydroxy-6-methoxyflavone, and caffeic acid into ferulic acid and isoferulic acid, respectively. Moreover, SaOMT5 turned out to be a $Mg^{2+}$-dependent OMT, and the effect of $Mg^{2+}$ ion on its activity was five times greater than those of $Ca^{2+}$, $Fe^{2+}$, and $Cu^{2+}$ ions, EDTA, and metal-free medium.

• Archives of Pharmacal Research
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• 제18권6호
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• pp.440-448
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• 1995

Fitty two flavones were synthesized from polyoxygenated dibenzoylmethanes which were obtained by a modified Baker-Venkatarman rearrangement, of 2-benzoyl oxyacetophenones. The following flavones among them showed good cytotoxic activities against L1210 and HL60 cells ; 2'-benzoyloxy-5,7-dimethoxyflavone $(8.2{\mu}g/ml,{\;}5.0 {\mu}g/ml)$, 2'-benzyloxy-5,7,8-trimethoxyflavone $(5,9 {\mu}g/ml,{\;}11.0{\mu}g/ml,{\;}2.7{\mu}g/ml)$, 2'-hydroxy-5,7,8-trimethoxyflavone $(9.8{\mu}/ml,{\;}6.2{\mu}g/ml)$, 2'-benzyloxy-5-hydroxyflavone $(5.2 {\mu}g/ml,{\;}3.6{\mu}g/ml)$, and 5,2'-dihydroxyflavone $(5.1{\mu}g/ml,{\;}4.0{\mu}g/ml)$. Presence of 5-methoxy group potentiated the cytotoxic activity, while the existence of 7-methoxy group decreased the activity. 5-Hydroxy or methoxy activates 4-carbonyl group, while 7-methoxy group deactivates the acrbonyl group. From these observation it was concluded that the activation of carbonyl group at C-4 of a flavone is important for the enahncement of the cytotoxic activity. The presence of both 5-hydroxy and 2-benzyloxy-or 2-hydroxy group enhanced the antitumor activity; 2'-benzyloxy-5-hydroxy-7-methoxyflaone 9T/C=144%), 5.2'-dihydroxy-7-methoxyflavone (T/C=132%) and 5,2'-dihydroxy-6,78,6' trtramethoxyflvone (T/C = 172%) 2'hexanolytion of 5,2'-dihydroxy-flavones did not improve the natitumor activity; 2' hexanoyloxy-5-hydroxy-7-methoxyflavone showed T/C = 132%, about the same as that of 5,2'-dihydroxy-7-methoxyflvone (T/C=130%)

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.2057-2060
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• 2005

• Biomolecules & Therapeutics
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• 제13권3호
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• pp.133-137
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• 2005

Wogonin(5,7-dihydroxy-8-methoxyflavone), an anti-inflammatory plant flavonoid, was previously demonstrated to modulate the several parameters of animal skin inflammation. This compound inhibited edematic response as well as proinflammatory gene expression. In this investigation, the histopathological changes of the lesions from different types of experimental skin inflammation were compared and the potential therapeutic effect of topically applied wogonin was evaluated. From the results, it was found that multiple TPA treatment drastically increased ear edema accompanied with epidermal hyperplasia and inflammatory cell infiltration, while phenol treatment provoked only edematic response in the dermal area. Wogonin somewhat differently inhibited these animal models of skin inflammation.

• Biomolecules & Therapeutics
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• 제14권1호
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• pp.36-39
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• 2006

Some flavones/flavonols were previously found to inhibit collagenase. To establish a therapeutic potential for skin inflammation, twenty-three synthetic flavone derivatives were examined for their inhibitory potential against collagenase from Clostridium histolyticum. From the results, it was found that most of them having various hydroxyl, methoxyl, methylsulfuryl and/or chloro substitution(s) on A- and B-rings were not efficient collagenase inhibitors. Among the synthetic flavones tested, only two synthetic derivatives, 3',4'-dihydroxyflavone and 5-hydroxy-4'-methoxyflavone, weakly inhibited bacterial collagenase (13-29% inhibition at 50-100 ${\mu}M$).

• 약학회지
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• 제53권6호
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• pp.377-381
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• 2009

Isowogonin, 5,8-dihydroxy-7-methoxyflavone, is a flavonoid isolated from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used since the ancient time. It was thought to possess a variety of biological activities, such as antioxidation, anti-inflammation and hepatoprotective effect. But a quantity of isowogonin obtained from Scutellaria baicalensis Georgi is not that enough for in vivo test. There have been no appropriate approaches available for a facile synthesis of isowogonin. So we describe a concise and efficient scheme for synthesis of isowogonin from a commercial available 2,4,6-trimethoxyphenol, which includes the Fries rearrangement and selective demethylation as key steps.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1261-1264
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• 2007

Bioassay-directed fractionations of the seed extracts of Trichosanthes kirilowii, have resulted in the isolation of two new compounds, 2-(4-hydroxy-3-methoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol (2) and isoetin 5'-methyl ether (5,7,2',4'-tetrahydroxy-5'-methoxyflavone) (3), together with two known compounds, 7-hydroxychromone (1) and 5,7,4'-trihydroxy-3',5'-dimethoxyflavone (tricin, 4). Their structures were characterized by spectroscopic analysis such as 2D-NMR, HRTOFMS, and UV. Compound 3 showed cytotoxicity against human lung cancer cell line A549, human skin melanoma SK-Mel-2, and mouse melanoma B16F1, with IC50 of 0.92, 8.0, and 7.23 μg/mL, respectively.

• Journal of the Korean Wood Science and Technology
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• 제13권4호
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• pp.58-66
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• 1985

In order to elucidate chemical structure of the wood extractives, softwood (Pinus koraiensis Sieb. et Zucc.) meal was extracted with 95% ethanol at room temperature for 72 hours. The extract was fractionated with organic solvents such as n-hexane, ether, ethylacetate, and acetone. From the n-hexane and ether soluble fraction of the wood extractives, four flavonoid compounds were isolated and identified as 5-hydroxy-7-methoxyflavone (I), 5-methoxy-7-hydroxyflavone (II), 5-hydroxy-7-methoxyflavanone (III), and 5-methoxy-7-hydroxyflavanone (IV) by UV, IR, $^1$H-NMR spectroscopy and MS spectrometry.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1793-1796
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• 2008

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.286.1-286.1
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• 2003

Chrysin, a natural flavone compound contained in plants. has anti-inflammatory activity. Its anti-inflammatory effect has been previously explained in part by the suppression of promoter activities of inducible pro-inflammatory enzymes (cyclooxygenase-2 (COX-2) and inducible nitrogen synthase (iNOS)). Nitrate production triggered by the activation of lipopolysaccharides (LPS) was most highly suppressed by the treatment of chrysin, follwed by 5-hydroxy-7-methoxyflavone (Ch-2), 5,7-diacetylflavone (Ch-4) in cultured Raw 264.7 cells. (omitted)