7478-60-6Relevant academic research and scientific papers
Synthesis of Flavonols via Pyrrolidine Catalysis: Origins of the Selectivity for Flavonol versus Aurone
Xiong, Wei,Wang, Xiaohong,Shen, Xianyan,Hu, Cuifang,Wang, Xin,Wang, Fei,Zhang, Guolin,Wang, Chun
supporting information, p. 13160 - 13176 (2020/11/23)
A novel synthetic method for flavonol from 2′-hydroxyl acetophenone and benzaldehyde promoted by pyrrolidine under an aerobic condition in water is established. This protocol was supported by efficient synthesis of 44 common examples and three natural products. The α, β-unsaturated iminium ion (enimine ion E) was proved to be the key intermediate in the reaction. H218O and 18O2 isotope tracking experiments demonstrated that both water and the aerobic atmosphere were necessary to ensure the transformation. The selectivity for flavonol or aurone was originated from solvent-triggered intermediates, which were determined by UV-visible spectra from isolated enimine. The phenol-iminium E-A is dominant in water and the ketoenamine intermediate E-B is prevalent in acetonitrile. In the presence of pyrrolidine and oxygen, E-A leads to flavonol through E-I, a zwitterionic-like phenoloxyl-iminium ion, following the key steps of cyclization and a [2 + 2] oxidation; E-B proceeds through path II, a radical process induced by photolysis of E-B with both pyrrolidine and oxygen, to afford aurone. Preliminary mechanistic studies are reported.
New alkoxy flavone derivatives targeting caspases: Synthesis and antitumor activity evaluation
Moreira, Joana,Ribeiro, Diana,Silva, Patrícia M. A.,Nazareth, Nair,Monteiro, Madalena,Palmeira, Andreia,Saraiva, Lucília,Pinto, Madalena,Bousbaa, Hassan,Cidade, Honorina
, (2019/01/14)
The antitumor activity of natural flavonoids has been exhaustively reported. Previously it has been demonstrated that prenylation of flavonoids allows the discovery of new compounds with improved antitumor activity through the activation of caspase-7 activity. The synthesis of twenty-five flavonoids (4-28) with one or more alkyl side chains was carried out. The synthetic approach was based on the reaction with alkyl halide in alkaline medium by microwave (MW) irradiation. The in vitro cell growth inhibitory activity of synthesized compounds was investigated in three human tumor cell lines. Among the tested compounds, derivatives 6, 7, 9, 11, 13, 15, 17, and 18 revealed potent growth inhibitory activity (GI50 10 μM), being the growth inhibitory effect of compound 13 related with a pronounced caspase-7 activation on MCF-7 breast cancer cells and yeasts expressing human caspase-7. A quantitative structure-activity relationship (QSAR) model predicted that hydrophilicity, pattern of ring substitution/shape, and presence of partial negative charged atoms were the descriptors implied in the growth inhibitory effect of synthesized compounds. Docking studies on procaspase-7 allowed predicting the binding of compound 13 to the allosteric site of procaspase-7.
Discovery of a Prenylated Flavonol Derivative as a Pin1 Inhibitor to Suppress Hepatocellular Carcinoma by Modulating MicroRNA Biogenesis
Zheng, Yuanyuan,Pu, Wenchen,Li, Jiao,Shen, Xianyan,Zhou, Qiang,Fan, Xin,Yang, Sheng-Yong,Yu, Yamei,Chen, Qiang,Wang, Chun,Wu, Xin,Peng, Yong
supporting information, p. 130 - 134 (2018/11/30)
Peptidyl-prolyl cis-trans isomerase Pin1 plays a crucial role in the development of human cancers. Recently, we have disclosed that Pin1 regulates the biogenesis of miRNA, which is aberrantly expressed in HCC and promotes HCC progression, indicating the therapeutic role of Pin1 in HCC therapy. Here, 7-(benzyloxy)-3,5-dihydroxy-2-(4-methoxyphenyl)-8-(3-methylbut-2-en-1-yl)-4H-chromen-4-one (AF-39) was identified as a novel Pin1 inhibitor. Biochemical tests indicate that AF-39 potently inhibits Pin1 activity with an IC50 values of 1.008 μm, and also displays high selectivity for Pin1 among peptidyl prolyl isomerases. Furthermore, AF-39 significantly suppresses cell proliferation of HCC cells in a dose- and time-dependent manner. Mechanistically, AF-39 regulates the subcellular distribution of XPO5 and increases miRNAs biogenesis in HCC cells. This work provides a promising lead compound for HCC treatment, highlighting the therapeutic potential of miRNA-based therapy against human cancer.
Synthesis of 5-subsituted flavonols via the Algar-Flynn-Oyamada (AFO) reaction: The mechanistic implication
Shen, Xianyan,Zhou, Qiang,Xiong, Wei,Pu, Wenchen,Zhang, Wei,Zhang, Guolin,Wang, Chun
, p. 4822 - 4829 (2017/07/17)
Herein, we report a synthetic method with improved selectivity for 5-substituted flavonols via the Algar-Flynn-Oyamada reaction (AFO), by using of sodium carbonate/hydrogen peroxide A series of 5-substituted flavonols was obtained with moderate to high yields. The mechanism of the AFO reaction was elucidated. LCMS analysis and in situ 1H NMR analysis indicated that the epoxide was involved in the transformation from chalcone to flavonol and/or aurone under alkaline base/peroxide conditions.
2-substituted benzopyran-4-one compounds and application thereof
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Paragraph 0199, (2016/10/08)
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.
Origin of Spectral Features and Acid-Base Properties of 3,7-Dihydroxyflavone and Its Monofunctional Derivatives in the Ground and Excited States
Serdiuk, Illia E.,Roshal, Alexander D.,B?azejowski, Jerzy
, p. 4325 - 4337 (2016/07/11)
Comprehensive spectral investigations of 3,7-dihydroxyflavone and its two derivatives, which each contain a methyl-blocked hydroxyl group, reveal complex radiation absorption in the 300-450 nm range and emission in the 370-650 nm range. The absorption and fluorescence characteristics of these compounds depend on the pH/H0 of the water/methanol media, which is caused by the existence of the compounds in various protolytic (cationic, neutral, anionic) and tautomeric forms. Combined analysis of steady-state, time-dependent and fluorescence decay spectral data enabled the identification of the emitting species, determination of their lifetimes with respect to radiative and nonradiative deactivation processes, fluorescence quantum yields, protolytic and tautomeric abilities under various conditions, and acidic dissociation constants of the cationic, neutral, and anionic forms of the compounds. Results of calculations carried out at the DFT and TD DFT levels of theory generally confirmed the experimental findings concerning tautomeric/protolytic transformations and equilibria. Computational methods also provided insight into possible tautomerization pathways. Electronically excited molecules are generally much more susceptible to tautomerization and acidic dissociation than ground-state ones. 3,7-Dihydroxyflavone exhibits distinguishable features among the compounds investigated and can be considered as potential spectral indicator of properties (polarity, hydrophobicity, hydrogen-bonding ability) and acidity/basicity of liquid environments.
Quantum-chemical analysis of the Algar-Flynn-Oyamada reaction mechanism
Serdiuk,Roshal,B?a?ejowski
, p. 396 - 403 (2014/08/05)
This work is devoted to improving the understanding of Algar-Flynn-Oyamada reaction mechanism and the analysis of factors that affect the formation of flavonols. The calculation of thermodynamic parameters for the key reaction steps pointed to a mechanism involving chalcone epoxides as intermediates. A correlation was identified between the nucleophilicity of oxygen atom at position 2' of epoxide anions and the yields of flavonols. An increased charge at the nucleophilic center was shown to reduce the effectiveness of β-cyclization of epoxide anions.
New approach to flavonols via base-mediated cyclization: Total synthesis of 3,5,6,7-tetramethoxyflavone
Kraus, George A.,Gupta, Vinayak,Kempema, Aaron
, p. 385 - 388 (2012/03/10)
A new methodology for the synthesis of flavonols is described. The key step is a base-mediated cyclization-isomerization-elimination reaction which results in the formation of flavonols. Using this strategy, three flavonols are synthesized and characteriz
Effect of flavonol derivatives on the carrageenin-induced paw edema in the rat and inhibition of cyclooxygenase-1 and 5-lipoxygenase in vitro.
Sobottka,Werner,Blaschke,Kiefer,Nowe,Dannhardt,Schapoval,Schenkel,Scriba
, p. 205 - 210 (2007/10/03)
Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chr
Flavonoids. 43. Deprotonation-initiated Aryl Migration with Sulfur Dioxide Extrusion: A Route to 2,3-Dihydro-2,3-diaryl-3-hydroxy-4H-1-benzopyran-4-ones
Patonay, Tamas,Hegedues, Laszlo,Patonay-Peli, Erzsebet
, p. 145 - 151 (2007/10/02)
Treatment of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with various bases afforded 2,3-dihydro-r-2-aryl-t-3-hydroxy-c-3-(4-nitrophenyl)-4H-1-benzopyran-4-ones in a deprotonation-initiated aryl migration followed by sulfur dioxide extrusion.In the presence of hydroxide and methoxide ions a secondary ring cleavage has also been observed.However, the reaction of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with cyanide ions gave 2,3-dihydro-r-2-aryl-t-4-cyano-c-3,c-4-epoxy-4H-1-benzopyrans in a carbonyl attack of cyanide followed by an internal substitution reaction.
