- Convenient synthesis of flavanone derivatives via oxa-Michael addition using catalytic amount of aqueous cesium fluoride
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A total of 36 flavanones, which included polycyclic aromatic and heterocyclic rings, were readily synthesized via oxa-Michael addition from the corresponding hydroxychalcones with a catalytic amount of aqueous cesium fluoride solution under mild conditions. This method could be applied to the scalable synthesis of eriodictyol as a known potent inhibitor of the SARS-CoV-2 spike protein.
- Miura, Motofumi,Shigematsu, Karin,Toriyama, Masaharu,Motohashi, Shigeyasu
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supporting information
(2021/10/25)
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- Synthesis of 5-subsituted flavonols via the Algar-Flynn-Oyamada (AFO) reaction: The mechanistic implication
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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.
- Shen, Xianyan,Zhou, Qiang,Xiong, Wei,Pu, Wenchen,Zhang, Wei,Zhang, Guolin,Wang, Chun
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p. 4822 - 4829
(2017/07/17)
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- The synthesis and synergistic antifungal effects of chalcones against drug resistant Candida albicans
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To identify effective and low toxicity synergistic antifungal compounds, 24 derivatives of chalcone were synthesized to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. The minimal inhibitory concentration (MIC80) and the fractional inhibitory concentration index (FICI) of the antifungal synergist fluconazole were measured against fluconazole-resistant Candida albicans. This was done via methods established by the clinical and laboratory standards institute (CLSI). Of the synthesized compounds, 2′-hydroxy-4′-methoxychalcone (8) exhibited the most potent in vitro (FICI = 0.007) effects. The structure activity relationship of the compounds are then discussed.
- Wang, Yuan-Hua,Dong, Huai-Huai,Zhao, Fei,Wang, Jie,Yan, Fang,Jiang, Yuan-Ying,Jin, Yong-Sheng
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p. 3098 - 3102
(2016/06/13)
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- Simple and efficient one step synthesis of functionalized flavanones and chalcones
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A facile and highly efficient microwave-assisted synthesis of functionalized chalcones and flavanones based on the Claisen-Schmidt condensation reaction is reported. The method describes the synthesis of flavanones in single step with excellent yield and it was revealed that position and number of substituents on acetophenones and aromatic aldehydes played a very crucial and key role in the construction of flavanone derivatives. Among the thirty two synthesized compounds, five chalcones and one flavanone were novel compounds.
- Albogami, Abdullah Saad,Karama, Usama,Mousa, Ahmed Amine,Khan,Al-Mazroa, Sara Abdullah,Alkhathlan, Hamad Z.
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p. 619 - 626
(2012/10/30)
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- In vitro inhibitory properties of ferrocene-substituted chalcones and aurones on bacterial and human cell cultures
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Two series of ten chalcones and ten aurones, where ferrocene replaces the C ring and with diverse substituents on the A ring were synthesized. The compounds were tested against two antibiotic-sensitive bacterial strains, E. coli ATCC 25922 and S. aureus ATCC 25923, and two antibiotic-resistant strains, S. aureus SA-1199B and S. epidermidis IPF896. The unsubstituted compound and those with methoxy substitution showed an inhibitory effect on all bacterial strains at minimum inhibitory concentrations ranging between 2 and 32 mg L -1. For four of these compounds, the effect was bactericidal, as opposed to bacteriostatic. The corresponding organic aurones did not show growth inhibition, underscoring the role of the ferrocene group. The methoxy-substituted aurones and the unsubstituted aurone also showed low micromolar (IC50) activity against MRC-5 non-tumoral lung cells and MDA-MB-231 breast cancer cells, suggesting non-specific toxicity.
- Tiwari, Keshri Nath,Monserrat, Jean-Philippe,Hequet, Arnaud,Ganem-Elbaz, Carine,Cresteil, Thierry,Jaouen, Gerard,Vessieres, Anne,Hillard, Elizabeth A.,Jolivalt, Claude
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experimental part
p. 6451 - 6457
(2012/09/21)
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- An efficient synthesis of novel tetrahydrochromeno[2,3-b]chromenes
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A series of novel tetrahydrochromeno[2,3-b]chromenes is synthesized via the acid-catalyzed dimerization reactions of 5-methoxy- or 6-methoxyflavenes. A rational mechanism for the observed rearrangement is proposed.
- Devakaram, Ruth,Black, David Stc.,Kumar, Naresh
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body text
p. 3636 - 3638
(2010/08/20)
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- Synthesis and inhibitory activity against COX-2 catalyzed prostaglandin production of chrysin derivatives
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A series of chrysin derivatives were prepared and evaluated for their inhibitory activities of cyclooxygenase-2 catalyzed prostaglandin production. Chrysin derivatives were prepared from 2-hydroxyacetophenone, 2,4-dihydroxyacetophenone and 2,6-dihydroxyacetophenone in 2 to 4 steps, respectively. Methxoylated chrysin derivatives were converted to the corresponding hydroxylated chrysin derivatives by the reaction with BBr 3 in good yields. The inhibitory activity of the chrysin derivatives against prostaglandin production from lipopolysaccharide-treated RAW 264.7 cells was measured. We found that chrysin derivatives with 3′,4′- dichloro substituents (5e, 6e and 7e) exhibited good inhibitory activity of prostaglandin production.
- Dao, Tran Thanh,Chi, Yeon Sook,Kim, Jeongsoo,Kim, Hyun Pyo,Kim, Sanghee,Park, Haeil
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p. 1165 - 1167
(2007/10/03)
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- Flavonoids: Structural requirements for antiproliferative activity on breast cancer cells
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Several classes of flavonoids (flavones, flavanones, 2′-hydroxychalcones and flavan-4-ols) having a variety of substituents on A ring were investigated for their antiproliferative activity against MCF-7 human breast cancer cells. Structure-activity relationships of these compounds were discussed. 2′-hydroxychalcones and methoxylated flavanones were found to be potent inhibitors of MCF-7 cells growth whereas flavones and flavan-4-ols appeared to be weak inhibitory agents except 7,8-dihydroxyflavone.
- Pouget, Christelle,Lauthier, Fabienne,Simon, Alain,Fagnere, Catherine,Basly, Jean-Philippe,Delage, Christiane,Chulia, Albert-Jose
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p. 3095 - 3097
(2007/10/03)
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- The Kinetics and Mechanism of the Cyclisation of Some 2'-Hydroxychalcones to Flavanones in Basic Aqueous Solution
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Rate coefficients for the chalcone-flavanone equilibration reaction have been established for some 2'-hydroxychalcones over the pH range (ca. 8-11) in which their 2'-hydroxy-groups undergo ionisation.The chalcones studied were the parent 2'-hydroxychalcone (I) and its following derivatives: 4'-OMe (II), 6'-OMe (III), 4'-OH (IV), 4',6'-Me2 (V), and 5',6'-benzo (VI).Pseudo-first-order rate coefficients (kobs) which, for the reversible reactions concerned, are the sum of the forward and reverse rate coefficients, were fitted to the kinetic form, kobs=kfA+k'fB+k''aOH- in which k and k' are the rate coefficients for the unimolecular cyclisation of neutral and of ionised chalcones respectively (fA and fB are the fractions of total chalcone present in the neutral and ionised forms at the pH concerned) and where k'' is the second-order rate coefficient for the reverse reaction of flavanone which involves hydroxide ion (activity aOH-).Data analysis gave rate coefficients and pKa values for all but chalcone (IV) which has a different kinetic form.A conjugate addition-elimination mechanism is proposed to account for the pH-rate profiles, one of which differs from that previously reported.Possible effects on rate coefficients of non-bonded interactions between 6'-substituents and carbonyl oxygen are briefly considered but the differences between chalcones with and without 6'-substituents are sufficiently small to deter prolonged discussion.There seems to be little serious hindrance of cyclisation for any of the 6'-substituted chalcone anions.
- Old, K. Barry,Main, Lyndsay
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p. 1309 - 1312
(2007/10/02)
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