572-32-7

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InChI:InChI=1/C18H16O7/c1-22-10-7-12(20)15-14(8-10)25-17(18(24-3)16(15)21)9-4-5-13(23-2)11(19)6-9/h4-8,19-20H,1-3H3

Upstream product

• 1221398-17-9 6,8-dibromo-3,7-O-dimethyltamarixetin 
• 186581-53-3 diazomethane 
• 117-39-5 quercetol 
• 74-88-4 methyl iodide 
• 77-78-1 dimethyl sulfate 
• 1612925-22-0 5,7-bis(benzyloxy)-2-(3,4-bis(benzyloxy)phenyl)-3-methoxy-4H-chromen-4-one 
• 116973-12-7 5,7-bis(benzyloxy)-2-(3,4-bis(benzyloxy)phenyl)-3-hydroxy-4H-chromen-4-one 
• 153-18-4 rutin 
• 1486-70-0 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-3-methoxy-chromen-4-on 
• 33429-83-3 3,4'-O-dimethylquercetin 

Downstream Products

• 72947-72-9 5,3'-dihydroxy-3,7,4'-trimethoxyflavone diacetate 
• 1245-15-4 retusin 
• 95938-85-5 2-(3-acetoxy-4-methoxy-phenyl)-3,5,7-trimethoxy-chromen-4-one 
• 1832-98-0 3'-hydroxy-3,5,7,4'-tetramethoxyflavone 
• 979-92-0 S-(5'-adenosyl)-L-homocysteine 
• 124458-89-5 3'-acetoxy-5-hydroxy-3,7,4'-trimethoxyflavone 

Relevant academic research and scientific papers

Synthesis, characterization, and cross-linking strategy of a quercetin-based epoxidized monomer as a naturally-derived replacement for BPA in epoxy resins

The natural polyphenolic compound quercetin was functionalized and cross-linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties using a microwave-assisted reaction on a gram scale to a

Methylation of Quercetin by Diazomethane and Hypoglycemic Activity of its Tetra-O-Methyl Ether

The tetra-O-methyl ether of quercetin (QU) 3 (54%), 3,7,4′-tri-O-methyl ether 4 (30%), and a previously unreported 3,7,3-tri-O-methyl ether of QU 5 (7%) were obtained via methylation of QU by an excess of diazomethane in dioxane. Their structures were established using 2D NMR (1H–1H COSY, 1H–1H NOESY, 1H–13C HSQC, 1H–13C HMBC). Tetra-O-methyl ether of QU 3 exhibited pronounced hypoglycemic activity, reduced alloxan-induced hyperglycemia in rats by 44.5% compared to a control, and was 2.7 times more active than QU.

Correlation study on methoxylation pattern of flavonoids and their heme-targeted antiplasmodial activity

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.

Quercetin analogs with high fetal hemoglobin-inducing activity

β-Thalassemia is the major health problems in developing countries, when affected patients and healthy carriers are numerous, resulting a total absence or severe decrease in the production of β-globin chains. The use of chemical agents for increasing the production of fetal hemoglobin (HbF) by reactivating γ-globin gene to balance excess α-globin chains is an alternative therapeutic approach. Therefore, the search for molecules exhibiting the property of inducing γ-globin gene expression is of great interest. In this report, we discovered that quercetin (1), the major flavonoid isolated from the heartwoods of the medicinal plant Anaxagorea luzonensis promoted the expression of γ-globin gene. Chemical modification of 1 to fourteen methyl ether analogs (2?15) was conducted. The structures of these compounds were established on the basis of their spectroscopic data and by comparison with those of the reported values. The parent flavonoid and its chemically modified analogs were investigated for their γ-globin gene induction for the first time. The parent compound 1 exhibited less induced γ-globin gene expression than cisplatin and hemin, the positive controls. 3,4′-Di-O-methylquercetin (7), the modified analog, significantly enhanced γ-globin gene expression with 2.6-fold change at 8 μM, which was slightly higher than cisplatin and hemin. Moreover, compounds 1 and 7 displayed less cytotoxic activity against K562::ΔGγAγEGFP cells than cisplatin. Structure-activity relationship (SAR) study revealed that the methoxyl groups at the 3- and 4?-positions and the free hydroxyl group at the 7-position are required for strong HbF-inducing activity.

A simple and effective preparation of quercetin pentamethyl ether from quercetin

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.

Synthesis and Antioxidant Activity of Quercetin Ethers

Quercetin (Q) methyl ethers were synthesized from CH3I under various conditions. The principal products from the reactions of Q with alkylhalides (CH3I, C4H9Br) in DMF were 3,7,4′-tri-O-alkyl ethers. The structures of the products were confirmed by PMR and 13C NMR spectra. The antioxidant activity of Q tetra- and tri-O-methyl ethers was demonstrated by chemiluminescence in model systems generating active oxygen species and promoting lipid peroxidation.

Synthesized quercetin derivatives stimulate melanogenesis in B16 melanoma cells by influencing the expression of melanin biosynthesis proteins MITF and p38 MAPK

In order to understand the effect of structure-activity relationships on melanogenesis using B16 melanoma cells, 19 quercetin derivatives were synthesized. Among the synthesized compounds, 3-O-methylquercetin (11) and 3′,4′,7-O-trimethylquercetin (14) increased melanin content more potently than the positive control theophylline, while exhibiting low cytotoxicity. Compound 11 exhibited less melanogenesis-stimulating activity than compound 14. However, 11 increased the expression of tyrosinase and tyrosinase-related protein 1 (TRP-1) to a greater extent than 14, thereby suggesting that melanogenesis in melanoma cells does not depend solely on the expression of the enzymes catalyzing melanin biosynthesis. Furthermore, 14 also stimulated the expression of the microphthalmia-associated transcription factor (MITF) and p-p38 mitogen activated protein kinase (MAPK), while they were not increased by 11. These results suggest that 11 may enhance the expression of tyrosinase and TRP-1 by regulating the proteasomal degradation of melanogenic enzymes and/or by activating other transcriptional factors regulating enzyme expression.

Biological evaluation and SAR analysis of O-methylated analogs of quercetin as inhibitors of cancer cell proliferation

Preclinical Research Using a high-throughout screening approach, the anticancer activities of 16 O-methylated (OMe) analogs of quercetin were assessed. The structure-activity relationships showed that OMe moieties at the 4′ and/or 7 positions were important for maintaining inhibitory activities against the 16 cancer cell lines. Furthermore, when the OH groups at the 3′ and 4′ positions were both replaced by OMe moieties, anticancer activity was enhanced.

Cytotoxic and NF-κB inhibitory sesquiterpene lactones from Piptocoma rufescens

Six new (1-6) and eight known germacranolide-type sesquiterpene lactones, along with several known phenylpropanol coumarates and methylated flavonoids, were isolated from the leaves of Piptocoma rufescens, collected in the Dominican Republic. The new compounds were identified by analysis of their spectroscopic data, with the molecular structure of 3 being established by single-crystal X-ray diffraction. The absolute configurations of the sesquiterpene lactones isolated were determined from their CD and NOESY NMR spectra, together with the analysis of Mosher ester reactions. Bioassay screening results showed the majority of the sesquiterpene lactones isolated (1-13) to be highly cytotoxic toward the HT-29 human colon cancer cell line, with the most potent compound being 15-deoxygoyazensolide (10, IC50, 0.26 μM). In addition, several of the sesquiterpene lactones exhibited NF-κB (p65) inhibitory activity.

Metabolism-based synthesis, biologic evaluation and SARs analysis of O-methylated analogs of quercetin as thrombin inhibitors

In blood, quercetin is mainly found in metabolized forms. In order to study the activities of these quercetin metabolites in cardiovascular disease, 17 methylquercetin derivatives were synthesized based on metabolism in vivo, their thrombin inhibition activity were evaluated through the analyzation of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB). The results showed that 6 methylquercetin derivatives had stronger inhibitory activities than that of quercetin. Preliminary SARs analysis showed that hydroxyl groups at C-3′ and C-4′ position in the B-ring and hydroxyl group at C-3 position in the C-ring played key roles in the thrombin inhibitory activity. The findings of this study would provide information for the exploitation and utilization of quercetin as thrombin inhibitor for thrombotic disease treatment.