- A new domino oxidation—rearrangement of 2,3-dihydrowogonin to negletein
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We report an expeditious, iodine-catalysed oxidation of 2,3-dihydrowogonin to negletein which comprises a Wessely–Moser rearrangement (WMR), associated not with an O-demethylation, as usual, but with an oxygen to oxygen methyl shift. In contrast, DDQ in 1
- Spoerlein-Guettler, Cornelia,Milius, Wolfgang,Obenauf, Johannes,Schobert, Rainer
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p. 1560 - 1562
(2018/03/29)
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- Activities of Wogonin Analogs and Other Flavones against Flavobacterium columnare
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In our on-going pursuit to discover natural products and natural product-based compounds to control the bacterial species Flavobacterium columnare, which causes columnaris disease in channel catfish (Ictalurus punctatus), we synthesized flavone and chalcone analogs, and evaluated these compounds, along with flavonoids from natural sources, for their antibacterial activities against two isolates of F. columnare (ALM-00-173 and BioMed) using a rapid bioassay. The flavonoids chrysin (1a), 5,7-dihydroxy-4′-methoxyflavone (11), isorhamnetin (26), luteolin (27), and biochanin A (29), and chalcone derivative 8b showed strong antibacterial activities against F. columnare ALM-00-173 based on minimum inhibition concentration (MIC) results. Flavonoids 1a, 8, 11, 13 (5,4′-dihydroxy-7-methoxyflavone), 26, and 29 exhibited strong antibacterial activities against F. columnare BioMed based upon MIC results. The 24-h 50% inhibition concentration (IC50) results revealed that 27 and 29 were the most active compounds against F. columnare ALM-00-173 (IC50 of 7.5 and 8.5 mg/l, resp.), while 26 and 29 were the most toxic compound against F. columnare BioMed (IC50 of 9.2 and 3.5 mg/l, resp.). These IC50 results were lower than those obtained for wogonin against F. columnare ALM-00-173 and F. columnare BioMed (28.4 and 5.4 mg/l, resp.). However, based on MIC results, none of the compounds evaluated in this study were as active as wogonin (MIC 0.3 mg/l for each F. columnare isolate). Further modification of the wogonin structure to enhance antibacterial is of interest.
- Tan, Cheng-Xia,Schrader, Kevin K.,Khan, Ikhlas A.,Rimando, Agnes M.
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p. 259 - 272
(2015/10/19)
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- COMPOSITION AND METHOD FOR TREATING OR PREVENTING INFLUENZA VIRUS INFECTION
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The present invention provides a pharmaceutical composition and method for treating or preventing influenza virus infection in a subject comprising administering the subject with a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of compounds provided in this invention. In addition, the prevent invention provides new compounds for treating or preventing influenza virus infection.
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Paragraph 0046
(2015/12/23)
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- Synthesis and anti-influenza activities of novel baicalein analogs
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A series of novel flavones derivatives were synthesized based on modification of the active ingredients of a traditional Chinese medicine Scutellaria baicalensis GEORGI and screened for anti-influenza activity. The synthetic baicalein (flavone) analogs, especially with the B-rings substituted with bromine atoms, were much more potent than oseltamivir or ribavirin against H1N1 Tamiflu-resistant (H1N1 TR) virus and usually with more favorable selectivity. The most promising were 5b, 5c, 6b and 6c, all displaying an 50% effective concentration (EC50) at around 4.0-4.5 μM, and a selective index (SI=50% cytotoxic concentration (CC50)/EC 50)>70. For seasonal H3N2-infected influenza virus, both 5a and 5b with SI >17.3 indicated superior to ribavirin. The flavonoids having both not-naturally-occurring bromo-substituted B-rings and appropriate hydroxyls positioning on the A-rings might be critical in determining the activity and selectivity against H1N1-Tamiflu-resistant infected influenza viruses.
- Chung, Shu-Ting,Chien, Pei-Yu,Huang, Wen-Hsin,Yao, Chen-Wen,Lee, An-Rong
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p. 415 - 421
(2014/05/20)
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- Oroxylin A analogs exhibited strong inhibitory activities against iNOS-mediated nitric oxide (NO) production
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A number of oroxylin A analogs were prepared and evaluated for their inhibitory activities against iNOS-mediated nitric oxide (NO) production from LPS-stimulated BV2 cells. The analogs were synthesized from purchased 2′-hydroxy-4,5,6-trimethoxyacetophenone and aldehydes in 3 steps. Among the tested compounds, several analogs (3b, 3c, 3d, 3f) exhibited strong inhibitory activities. Especially, the analog with 4-nitrophenyl group (3b) showed stronger inhibitory activity (IC50 = 4.73 μM) than that of wogonin (IC50 = 7.80 μM).
- Pham, Tuan-Ahn. N.,Che, Haiyan,Phan, Phuong-Thuy T.,Lee, Jae-Won,Kim, Sung-Soo,Park, Haeil
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scheme or table
p. 2534 - 2535
(2012/05/05)
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- 4′-Bromo-5,6,7-trimethoxyflavone represses lipopolysaccharide-induced iNOS and COX-2 expressions by suppressing the NF-κB signaling pathway in RAW 264.7 macrophages
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The regulations of the NO and PGE2 productions are research topics of interest in the field of anti-inflammatory drug development. In the present study, 5,6,7-trimethoxy- and 5,6,7-trihydroxyflavones 3a-3g were synthesized from cinnamic acid derivatives. In particular, 4′-bromo-5,6,7- trimethoxyflavone (3b) most potently inhibited the productions of NO and PGE2 in LPS-treated RAW 264.7 cells (IC50 = 14.22 ± 1.25 and 10.98 ± 6.25 μM, respectively), and these inhibitory effects were more potent than those of oroxylin A or baicalein. Consistent with these findings, 3b concentration-dependently reduced the LPS-induced expressions of iNOS and COX-2 at the protein and mRNA levels. In addition, the release of TNF-α, IL-6, and IL-1β and the mRNA expressions of these cytokines were reduced by 3b in a concentration-dependent manner. Furthermore, 3b attenuated the LPS-induced transcriptional activities of NF-κB and this was accompanied by parallel reductions in the degradation and phosphorylation of IκB-α, and consequently by a decrease in the nuclear translocation of the p65 subunit of NF-κB. Taken together, these results suggest that suppressions of the expressions of iNOS, COX-2, TNF-α, IL-6, and IL-1β via NF-κB inactivation are responsible for the anti-inflammatory effects of 3b.
- Kim, Dong Han,Yun, Chang Hyeon,Kim, Min Hwan,Naveen Kumar, Ch.,Yun, Bo Hee,Shin, Ji-Sun,An, Hyo Jin,Lee, Young Hun,Yun, Yong Don,Rim, Hong-Kun,Yoo, Min-Sang,Lee, Kyung-Tae,Lee, Yong Sup
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p. 700 - 705
(2012/03/26)
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- Total synthesis of baicalein
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In this paper, a simple and novel synthesis of baicalein is described. This transformation features the novel synthesis of helilandin B and a different way to demethylate. The overall yield of 59% is acceptable.
- Chen, Duo-Zhi,Yang, Jian,Yang, Bo,Wu, Yuan-Shuang,Wu, Ting
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experimental part
p. 124 - 128
(2010/08/05)
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- α-Glucosidase inhibition of 6-hydroxyflavones. Part 3: Synthesis and evaluation of 2,3,4-trihydroxybenzoyl-containing flavonoid analogs and 6-aminoflavones as α-glucosidase inhibitors
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The SAR studies suggested that the C-ring of baicalein (1) was not necessary for the activity, and validated the importance of 2,3,4- trihydroxybenzoyl structure of 1. Thus, a series of 2,3,4-trihydroxybenzoyl- containing flavonoid analogs were investigat
- Gao, Hong,Kawabata, Jun
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p. 1661 - 1671
(2007/10/03)
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- Methods of synthesizing flavonoids and chalcones
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Simple and efficient total syntheses of flavonoids including baicalein, oroxylin A and wogonin are described herein. Simultaneous syntheses of oroxylin A and wogonin are also described.
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- Synthesis and anticancer activities of 5,6,7-trimethylbaicalein derivatives
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The aim of this study was to develop potential anticancer agents based on a naturally occurring baicalein, a flavonoid from Scatellariae radix. Cinnamic acid derivatives were converted to corresponding chlorides and then condensed with 3,4,5-trimethoxyphe
- Liao, Hua-Lin,Hu, Ming-Kuan
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p. 1162 - 1165
(2007/10/03)
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- Novel synthesis of flavonoids of Scutellaria baicalensis Georgi.
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A concise and efficient total synthesis of the flavonoids baicalein, oroxylin A and wogonin was described. Intramolecular oxidative cyclization followed by demethylation of chalcone 1, readily prepared from trimethoxyphenol, afforded, depending upon the controlled conditions, baicalein or oroxylin A in excellent yields. Demethylation of 1 yielded 3, which, by oxidation with I(2)/dimethyl sulfoxide (DMSO), was readily converted to oroxylin A and wogonin after column chromatography.
- Huang, Wen-Hsin,Chien, Pei-Yu,Yang, Ching-Huey,Lee, An-Rong
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p. 339 - 340
(2007/10/03)
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- Synthesis of some commonly occurring 2-phenyl-4H-1-benzopyran-4-ones: Revised structures for three natural products
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5-Hydroxy-6,7-dimethoxyflavone, 5-hydroxy-7,8-dimethoxyflavone, 5-hydroxy-3,7-dimethoxyflavone, 3-hydroxy-5,7-dimethoxyflavone, 5-hydroxy-7,8-dimethoxyisoflavone and 5,7-dihydroxy-3-methoxyflavone and their derivatives have been synthesised to confirm the
- Parmar, Virinder S.,Gupta, Sandhya,Sinha, Rita,Sharma, Sunil K.
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p. 244 - 256
(2007/10/02)
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- 13C Nuclear Magnetic Resonance Studies on 1,3-Diphenylprop-2-enones
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The 13C NMR spectra of 48 differently substituted chalcones (1,3-diphenylprop-2-enones) have been recorded and the results are discussed.The data will be useful in the identification of new/natural chalcones.
- Parmar, V. S.,Sharma, Sunil,Rathore, J. S.,Garg, Meenu,Gupta, Sandhya,et al.
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p. 470 - 474
(2007/10/02)
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