7251-37-8Relevant academic research and scientific papers
Synthesis of fisetin and 2′,4′,6′-trihydroxydihyrochalcone 4′-O-β-neohesperidoside based on site-selective deacetylation and deoxygenation
Tsunekawa, Ryuji,Hanaya, Kengo,Higashibayashi, Shuhei,Sugai, Takeshi
, p. 1316 - 1322 (2018/07/29)
Fisetin and 2′,4′,6′-trihydroxydihyrochalcone 4′-O-β-neohesperidoside were synthesized from commercially available quercetin and naringin in five steps. The key steps are site-selective deacetylation and subsequent deoxygenation. The target molecules were obtained in 37% and 23% yields from the starting materials, respectively.
Binding investigation between M2-1protein from hRSV and acetylated quercetin derivatives: 1H NMR, fluorescence spectroscopy, and molecular docking
Guimar?es, Giovana C.,Piva, Hemily R.M.,Araújo, Gabriela C.,Lima, Caroline S.,Regasini, Luis O.,de Melo, Fernando A.,Fossey, Marcelo A.,Caruso, ícaro P.,Souza, Fátima P.
, p. 33 - 38 (2018/01/10)
The human Respiratory Syncytial Virus (hRSV) is the main responsible for occurrences of respiratory diseases as pneumonia and bronchiolitis in children and elderly. M2-1 protein from hRSV is an important antitermination factor for transcription process that prevents the premature dissociation of the polymerase complex, making it a potential target for developing of inhibitors of the viral replication. The present study reports the interaction of the M2-1 tetramer with pera (Q1) and tetracetylated (Q2) quercetin derivatives, which were synthesized with the objective of generating stronger bioactive compounds against oxidation process. Fluorescence experiments showed binding constants of the M2-1/compounds complexes on order of 104 M? 1 with one ligand per monomeric unit, being the affinity of Q2 stronger than Q1. The thermodynamic analysis revealed values of ΔH > 0 and ΔS > 0, suggesting that hydrophobic interactions play a key role in the formation of the complexes. Molecular docking calculations indicated that binding sites for the compounds are in contact interfaces between globular and zinc finger domains of the monomers and that hydrogen bonds and stacking interactions are important contributions for stabilization of the complexes. Thus, the interaction of the acetylated quercetin derivatives in the RNA-binding sites of M2-1 makes these potential candidates for viral replication inhibitors.
Quercetin derivative and its preparation method and application
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Paragraph 0025, (2018/01/19)
The invention discloses a quercetin derivative and a preparation method and application thereof. The preparation method comprises the following steps: firstly using dichlorodiphenylmethane to protect quercetin o-diphenol hydroxyl, combining a benzyl protection group to obtain the selectively protected quercetin derivative, and then independently reacting with dimethyl sulfate, diethyl sulfate, allyl bromide, paratoluensulfonyl chloride and acetic anhydride respectively to generate corresponding quercetin derivatives. All of the prepared derivative compounds have NRK-49F proliferation activity inhibition superior to that of quercetin. The quercetin derivatives 20a-1, 14a-1 and 23d-1 compositely replaced by methyl and p-tosyl have higher inhibition NRK-49F proliferation activity, and the inhibition ratio respectively reaches 86.33%, 78.04% and 75.91%. Thus, the currently obtained quercetin derivative compounds have obvious inhibition effect on kidney fibroblast NRK-49F proliferation.
Epimerization, transacylation and bromination of dihydroquercetin acetates; Synthesis of 8-bromodihydroquercetin
Kiehlmann, Eberhard,Szczepina, Monica G.
experimental part, p. 492 - 498 (2012/05/20)
Dihydroquercetin (dhq) and its 3-acetate react with acetic anhydride in the absence of a base catalyst to yield mixtures of partially acetylated products. Three new esters were characterized by NMR spectroscopy as dhq 3,7,3'-triacetate, 3,7,4'-triacetate and 5,7,3',4'- tetraacetate. At its melting point neat dhq 3,7,3',4'-tetraacetate is partially converted to dhq 3,3',4'-triacetate and dhq pentaacetate by intermolecular acetyl transfer. Dhq 7,3',4'-triacetate yields exclusively dhq 3',4'-di- and 3,7,3',4'-tetraacetate under these conditions. The acetylation/deacetylation reactions are accompanied by partial epimerization: 3 new acetates with 2,3-cis stereochemistry (dhq 3-, 3,7,3',4'-tetra- and penta-) were identified. Dhq and its 3,7,3',4'-tetraacetate undergo regiospecific dibromination at C-6 and C-8 with excess N-bromosuccinimide in polar solvents, and 6,8-dibromo-dhq can be regioselectively debrominated to 8-bromo-dhq with sodium sulfite. Versita Sp. z o.o.
Regioselective O-derivatization of quercetin via ester intermediates. An improved synthesis of rhamnetin and development of a new mitochondriotropic derivative
Mattarei, Andrea,Biasutto, Lucia,Rastrelli, Federico,Garbisa, Spiridione,Marotta, Ester,Zoratti, Mario,Paradisi, Cristina
experimental part, p. 4722 - 4736 (2010/10/20)
The regioselective synthesis of several quercetin (3,3',4',5,7-pentahydroxy flavone) tetraesters bearing a single free OH on 5-C was achieved in good yield by proper choice of reaction conditions using common esterification procedures. Tetracetylated quercetin with the free OH on 7-C was selectively obtained instead via imidazole-promoted deacylation of the corresponding pentaester. Unambiguous structural characterization of the two isomeric tetraacetyl quercetin derivatives was obtained by combined HSQC and HMBC 2D-NMR analysis. These molecules can be used as starting materials for the regioselective synthesis of other derivatives. High yield syntheses of the natural polyphenol rhamnetin (7-O-methylquercetin) and of the new mitochondriotropic compound 7-(4-triphenylphosphoniumbutyl) quercetin iodide are reported as examples.
Selective C-6 prenylation of flavonoids via europium(III)-catalyzed claisen rearrangement and cross-metathesis
Tischer, Sandra,Metz, Peter
, p. 147 - 151 (2008/02/03)
Starting from the readily available parent flavonoids, the flavanone 6-prenylnaringenin, the isoflavone 6-prenylgenistein (wighteone, erythrinin B) and a protected derivative of the flavonol 6-prenylquercetin (gancaonin P) have been synthesized in short reaction sequences featuring the title processes as key steps.
Phytochemical analysis and laxative activity of the leaf extracts of Euphorbia heterophylla Linn (Euphorbiaceae)
Falodun,Agbakwuru
, p. 345 - 348 (2007/10/03)
A hot aqueous decoction of the leaves of Euphorbia heterophylla Linn (Euphorbiaceae) 1.24 kg gave on cooling and defatting with dichloromethane, an aqueous solution which on successively extracting with n-butanol and ethylacetate gave 25.89g and 1.31g of residue, respectively on removal of solvent. The semi-solid extract from the ethylacetate fraction on hydrolysis with dilute tetraoxosulphate (VI) acid gave a yellow powder which on acetylation gave colourless needle clusters identified as quercetin tetracetate. The butanolic fraction had laxative action and contained saponins, phenols, terpenes and diterpenes identified as phorbols but no anthraquinones. The residual aqueous solution contained mainly sugars identified as xylose, maltose, galactose, lactose and lactulose, which are bulkforming laxatives. The purgative action was found to be a joint action of both the phorbols in the butanol fraction and the bulk forming laxative sugars in the residual aqueous fraction.
