1247-97-8Relevant articles and documents
O-ALKYLATION DE LA QUERCETINE ET SYNTHESE DE LA TETRA-O-EHYL-3,7,3',4' O-ETHYL -5 QUERCETINE
Picq, M.,Prigent, A. F.,Chabannes, B.,Pacheco, H.,Parent, P.,Pichat, L.
, p. 2227 - 2230 (1984)
An efficient procedure is described for alkylation of quercetin with alkyl halides by use of tetraethylammonium fluoride in DMF or HMPT.The method is applied successfully to the preparation of 3,7,3',4', tetra-O-ethyl 5 O-ethylquercetin with a specific radioactivity of 45 Ci/mmol.
A flavonol glycoside-lignan ester and accompanying acylated glucosides from Monochaetum multiflorum
Isaza, Jose H,Ito, Hideyuki,Yoshida, Takashi
, p. 321 - 327 (2001)
Four acylated glycosides along with six known glycosides were isolated from the leaves of Monochaetum multiflorum. The new compounds were characterized as 4.0-(6′-O-galloyl- β- glucopyranosyl)-cis-p-coumaric acid, 6′-O- galloylprunasin, benzyl 6′-O-galloyl-β-glucopyranoside, and a novel diester of tetrahydroxy-μ-truxinic acid with 2 mol of hyperin (monochaetin), based on NMR and MS spectral data and chemical evidence.
Method of producing an alkoxyflavone derivative
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Page/Page column 6, (2021/01/20)
A method of producing an alkoxyflavone derivative involves a step of reacting hydroxyflavone derivative which is shown in the below chemical formula and dialkyl sulfate in the presence of dimethyl sulfoxide and an alkali hydroxide. Further, in the chemical formula below, R11-R14, R21-R25 and R3 are independently one of hydrogen, hydroxyl group, ester group, alkoxy group, alkylenedioxy group, sulfonyl group and alkyl group, respectively. However, at least two of R21-R25 and R3 are hydroxyl groups.
Correlation study on methoxylation pattern of flavonoids and their heme-targeted antiplasmodial activity
Boutefnouchet, Sabrina,Bouzidi, Chouaha,Cojean, Sandrine,Figadère, Bruno,Grougnet, Rapha?l,Maciuk, Alexandre,Michel, Sylvie,Ortiz, Sergio,Vásquez-Ocmín, Pedro G.
, (2020/09/16)
A library of 33 polymethoxylated flavones (PMF) was evaluated for heme-binding affinity by biomimetic MS assay and in vitro antiplasmodial activity on two strains of P. falciparum. Stability of heme adducts was discussed using the dissociation voltage at 50% (DV50). No correlation was observed between the methoxylation pattern and the antiparasitic activity, either for the 3D7 chloroquine-sensitive or for the W2 chloroquine-resistant P. falciparum strains. However, in each PMF family an increased DV50 was observed for the derivatives methoxylated in position 5. Measurement of intra-erythrocytic hemozoin formation of selected derivatives was performed and hemozoin concentration was inversely correlated with heme-binding affinity. Kaempferol showed no influence on hemozoin formation, reinforcing the hypothesis that this compound may exert in vitro antiplasmodial activity mostly through other pathways. Pentamethoxyquercetin has simultaneously demonstrated a significant biological activity and a strong interaction with heme, suggesting that inhibition of hemozoin formation is totally or partially responsible for its antiparasitic effect.
A simple and effective preparation of quercetin pentamethyl ether from quercetin
Tatsuzaki, Jin,Ohwada, Tomohiko,Otani, Yuko,Inagi, Reiko,Ishikawa, Tsutomu
supporting information, p. 3112 - 3121 (2019/01/21)
Among the five hydroxy (OH) groups of quercetin (3,5,7,3',4'-pentahydroxyflavone), the OH group at 5 position is the most resistant to methylation due to its strong intramolecular hydrogen bonding with the carbonyl group at 4 position. Thus, it is generally difficult to synthesize the pentamethyl ether efficiently by conventional methylation. Here, we describe a simple and effective perO-methylation of quercetin with dimethyl sulfate in potassium (or sodium) hydroxide/dimethyl sulfoxide at room temperature for about 2 hours, affording quercetin pentamethyl ether (QPE) quantitatively as a single product. When methyl iodide was used in place of dimethyl sulfate, the C-methylation product 6-methylquercetin pentamethyl ether was also formed. A computational study provided a rationale for the experimental results.
