- Unraveling the anti-influenza effect of flavonoids: Experimental validation of luteolin and its congeners as potent influenza endonuclease inhibitors
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The biological effects of flavonoids on mammal cells are diverse, ranging from scavenging free radicals and anti-cancer activity to anti-influenza activity. Despite appreciable effort to understand the anti-influenza activity of flavonoids, there is no clear consensus about their precise mode-of-action at a cellular level. Here, we report the development and validation of a screening assay based on AlphaScreen technology and illustrate its application for determination of the inhibitory potency of a large set of polyols against PA N-terminal domain (PA-Nter) of influenza RNA-dependent RNA polymerase featuring endonuclease activity. The most potent inhibitors we identified were luteolin with an IC50 of 72 ± 2 nM and its 8-C-glucoside orientin with an IC50 of 43 ± 2 nM. Submicromolar inhibitors were also evaluated by an in vitro endonuclease activity assay using single-stranded DNA, and the results were in full agreement with data from the competitive AlphaScreen assay. Using X-ray crystallography, we analyzed structures of the PA-Nter in complex with luteolin at 2.0 ? resolution and quambalarine B at 2.5 ? resolution, which clearly revealed the binding pose of these polyols coordinated to two manganese ions in the endonuclease active site. Using two distinct assays along with the structural work, we have presumably identified and characterized the molecular mode-of-action of flavonoids in influenza-infected cells.
- Albi?ana, Carlos Berenguer,Brynda, Ji?í,Fanfrlík, Jind?ich,Flieger, Miroslav,Hodek, Jan,Karlukova, Elena,Ko?í?ek, Milan,Konvalinka, Jan,Machara, Ale?,Majer, Pavel,Radilová, Kate?ina,Weber, Jan,Zima, Václav
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- 2-substituted benzopyran-4-one compounds and application thereof
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The invention relates to the technical field of medicine and discloses 2-substituted benzopyran-4-one compounds with a structure shown in general formula I and an application of the compounds in preparation of antifungal drugs and synergistic antifungal drugs. The compounds can be jointly used with azole antifungal drugs, can improve sensibility of drug-resistance bacteria to the azole drugs, reverses drug resistance and produces a synergistic antifungal function.
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Paragraph 0161; 0162; 0163; 0244; 0245; 0246
(2016/10/08)
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- Synthesis of 3-Acyl- and 3-Carbamoylflavones
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Routes to 3-acyl-, 3-carboxamido- and polyhydroxylated flavones have been devised by application of isoxazole methodology and Heck-Stille couplings.Reductive ring opening of 3-alkoxyisoxazoles gives β-keto carboxamides in contrast with 3-alkoxy-2-isoxazolines, which give β-hydroxy esters.
- Ellemose, Steen,Kure, Niels,Torsell, Kurt B. G.
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p. 524 - 529
(2007/10/02)
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