- Idnhibition of antibacterial resistance by 3',4'-difluoroquercetin and its derivative
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The present invention relates to 3andprime;,4andprime;-difluoroquercetin having antibacterial activity on multiple drug resistant bacteria and a novel derivative thereof. A quercetin derivative compound of the present invention exhibits a significant antibacterial activity on Gram-positive multiple drug resistant bacteria, exhibits strong antibacterial activity only on Gram-negative multiple drug resistant bacteria, and a significant synergistic effect occurs when an antibiotic which does not have antibacterial activity or has low antibacterial activity and the compound of the present invention are mixed and treated in Gram-negative multiple drug resistant bacteria, thereby being able to exhibit an excellent antibacterial effect on Gram-positive multiple drug resistant bacteria, Gram-negative multiple drug resistant bacteria, and antibiotic-resistant bacteria thereof.COPYRIGHT KIPO 2020
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Paragraph 0097-0099
(2020/09/16)
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- 11-β-hydroxysterols as possible endogenous stimulators of mitochondrial biogenesis as inferred from epicatechin molecular mimicry
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Currently, there is great interest in identifying endogenous (i.e. physiological) stimulators of mitochondrial biogenesis (MB), in particular, those that may mediate the effects of exercise. The molecular size of the cacao flavanols (epicatechin and catechin) highly resembles that of sterols and epicatechin has been reported to activate cells surface receptors leading to the stimulation of MB in endothelial and skeletal muscle cells translating into enhanced exercise capacity. We therefore hypothesize, that epicatechin may be acting as a structural mimic of an as yet unknown sterol capable of stimulating MB. We developed a new synthetic process for obtaining enantiomerically pure preparations of (-)-epicatechin and (+)-epicatechin. Applying spatial analytics and molecular modeling, we found that the two isoforms of epicatechin, (-) and (+), have a structural resemblance to 11-β-hydroxypregnenolone, a sterol with no previously described biological activity. As reported in this proof-of-concept study performed in primary cultures of endothelial and muscle cells, 11-β-hydroxypregnenolone is one of the most potent inducers of MB as significant activity can be detected at femtomolar levels. The relative potency of (-)/(+)-epicatechin isoforms and on inducing MB correlates with their degree of spatial homology towards the 11-β-hydroxypregnenolone. On the basis of these results, the detailed in vivo characterization of the potential for these sterols to act as endogenous modulators of MB is warranted.
- Dugar, Sundeep,Villarreal, Francisco,Hollinger, Frank H.,Mahajan, Dinesh,Ramirez-Sanchez, Israel,Moreno-Ulloa, Aldo,Ceballos, Guillermo,Schreiner, George
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- Natural and Synthetic Flavonoids as Potent Mycobacterium tuberculosis UGM Inhibitors
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This study reports a novel class of inhibitors of uridine 5′-diphosphate (UDP) galactopyranose mutase (UGM) derived from a screening of natural products. This enzyme is an essential biocatalyst involved in the cell wall biosynthesis of Mycobacterium tuberculosis. Flavonoids are potent inhibitors of UGM. The synthesis of novel methylated flavonoids allowed a structure–activity relationship analysis to be performed and which functional groups and structural elements were required for UGM inhibition could be determined. The binding mode of one of the best inhibitors was found to be noncompetitive. Docking simulations indicated that this molecule was likely to bind UGM in its open conformation, in a cavity recently identified as a “druggable” pocket. Importantly, two of the best inhibitors of the M. tuberculosis UGM displayed moderate activity against whole M. tuberculosis cells. This study reports the first natural products that act as inhibitor of UGM. Given the importance of natural products in medicinal chemistry, these results create new opportunities for the discovery of new antitubercular agents.
- Villaume, Sydney A.,Fu, Jian,N'Go, Inès,Liang, Hui,Lou, Huayong,Kremer, Laurent,Pan, Weidong,Vincent, Stéphane P.
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supporting information
p. 10423 - 10429
(2017/08/07)
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- Quercetin derivatives as novel antihypertensive agents: Synthesis and physiological characterization
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The antihypertensive flavonol quercetin (Q1) is endowed with a cardioprotective effect against myocardial ischemic damage. Q1 inhibits angiotensin converting enzyme activity, improves vascular relaxation, and decreases oxidative stress and gene expression. However, the clinical application of this flavonol is limited by its poor bioavailability and low stability in aqueous medium. In the aim to overcome these drawbacks and preserve the cardioprotective effects of quercetin, the present study reports on the preparation of five different Q1 analogs, in which all OH groups were replaced by hydrophobic functional moieties. Q1 derivatives have been synthesized by optimizing previously reported procedures and analyzed by spectroscopic analysis. The cardiovascular properties of the obtained compounds were also investigated in order to evaluate whether chemical modification affects their biological efficacy. The interaction with β-adrenergic receptors was evaluated by molecular docking and the cardiovascular efficacy was investigated on the ex vivo Langendorff perfused rat heart. Furthermore, the bioavailability and the antihypertensive properties of the most active derivative were evaluated by in vitro studies and in vivo administration (1 month) on spontaneously hypertensive rats (SHRs), respectively. Among all studied Q1 derivatives, only the ethyl derivative reduced left ventricular pressure (at 10- 8 M ÷ 10- 6 M doses) and improved relaxation and coronary dilation. NOSs inhibition by L-NAME abolished inotropism, lusitropism and coronary effects. Chronic administration of high doses of this compound on SHR reduced systolic and diastolic pressure. Differently, the acetyl derivative induced negative inotropism and lusitropism (at 10- 10 M and 10- 8 ÷ 10- 6 M doses), without affecting coronary pressure. Accordingly, docking studies suggested that these compounds bind both β1/β2-adrenergic receptors. Taking into consideration all the obtained results, the replacement of OH with ethyl groups seems to improve Q1 bioavailability and stability; therefore, the ethyl derivative could represent a good candidate for clinical use in hypertension.
- Grande, Fedora,Parisi, Ortensia I.,Mordocco, Roberta A.,Rocca, Carmine,Puoci, Francesco,Scrivano, Luca,Quintieri, Anna M.,Cantafio, Patrizia,Ferla, Salvatore,Brancale, Andrea,Saturnino, Carmela,Cerra, Maria C.,Sinicropi, Maria S.,Angelone, Tommaso
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p. 161 - 170
(2015/12/11)
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- NOVEL APPROACH FOR SYNTHESIS OF CATECHINS
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A process for synthesis of enatiomerically pure or enatiomerically enriched or racemic mixture of (+and/or?) epicatechin echm and its intermediates, comprising the steps of: (i) obtaining penta-protected quercetin; (ii) reducing the penta-protected quercetin obtained from step (i); (iii) optionally deprotecting the compound of step (ii); (iv) reducing the compound obtained from step (ii) or step (iii) in the presence of a chiral/achiral reducing agent to obtain a chiral intermediate; (v) deprotecting and/or hydrogenation of the chiral intermediate obtained from step (iv) to obtain (?)-epicatechin; (vi) optionally simultaneously deprotecting and by drogenation of the compound obtained from step (ii) to obtain racemic epicatechin.
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Paragraph 0138; 0139; 0140; 0141
(2016/01/15)
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- NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives. A principle objective of the disclosure is to provide a new and useful method of synthesis to obtain polyphenols in isomerically pure and/or racemic forms.
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Paragraph 0034; 0142; 0143; 0144; 0145
(2014/02/16)
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- Synthesis and identification of quercetin benzyl ethers
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We have studied the effects of the benzylating agent character, the reactants ratio, and the solvent nature on the composition of the products of quercetin benzylation. The structure of the products has been confirmed by IR, UV, 1H NMR, 13
- Karimova,Spirikhin,Baltina,Abdullin
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p. 1711 - 1715
(2015/01/09)
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- Regioselective iodination of flavonoids by N-iodosuccinimide under neutral conditions
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Regioselective synthesis of C-6 and C-8 monoiodo flavonoids, which are important intermediates for the synthesis of flavonoid natural products and drug molecules, was achieved by iodination of suitably alkylated flavonoids with N-iodosuccinimide (NIS) in DMF. The iodination gives either a C-6 or C-8 iodo flavonoid in high yield, depending on the protection pattern of the C-5 and C-7 OH groups. The mild and neutral conditions render this novel protocol particularly useful for the regioselective iodination of acid-sensitive substrates.
- Lu, Kui,Chu, Jie,Wang, Haomeng,Fu, Xiaoli,Quan, Dewu,Ding, Hongxia,Yao, Qingwei,Yu, Peng
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supporting information
p. 6345 - 6348
(2013/11/06)
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- A NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives.
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Page/Page column 29-30
(2012/08/08)
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- Regiospecific synthesis of quercetin O-β-d-glucosylated and O-β-d-glucuronidated isomers
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Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.
- Kajjout, Mohammed,Rolando, Christian
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supporting information; experimental part
p. 4731 - 4741
(2011/07/08)
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- Selective monomethylation of quercetin
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Quercetin was monomethylated under mild conditions in moderate yields through selective deprotection. The combined effects of the protecting group and the heating mode on the reactivity were investigated. The presence of borax and the use of microwave irradiation significantly improved the yield and selectivity of alkylation. Georg Thieme Verlag Stuttgart - New York.
- Zhou, Zhong-Hua,Fang, Zhuan,Jin, Hui,Chen, Yue,He, Ling
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experimental part
p. 3980 - 3986
(2011/02/22)
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- Hemisynthesis of all the O-monomethylated analogues of quercetin including the major metabolites, through selective protection of phenolic functions
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A new methodology for the hemisynthesis of all the five O-monomethylated analogues of quercetin (3′-O-methylquercetin (isorhamnetin), 4′-O-methylquercetin (tamarixetin), 3-O-methylquercetin, 5-O-methylquercetin (azaleatin) and 7-O-methylquercetin (rhamnetin)) through sequential protection of the different phenolic functions of quercetin is reported.
- Bouktaib, Mohamed,Lebrun, Stéphane,Atmani, Aziz,Rolando, Christian
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p. 10001 - 10009
(2007/10/03)
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- Isotopic labelling of Quercetin 4'-O-β-D-glucoside
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[2-13C]-Quercetin-4'-O-β-glucoside was synthesised in four steps and 28% yield from barium [13C]-carbonate. This short route will be applicable to the synthesis of radiolabelled quercetin-4'-O-β-D-glucoside from barium [14
- Caldwell, Stuart T.,Crozier, Alan,Hartley, Richard C.
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p. 4101 - 4106
(2007/10/03)
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- O-ALKYLATION DE LA QUERCETINE ET SYNTHESE DE LA TETRA-O-EHYL-3,7,3',4' O-ETHYL -5 QUERCETINE
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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.
- Picq, M.,Prigent, A. F.,Chabannes, B.,Pacheco, H.,Parent, P.,Pichat, L.
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p. 2227 - 2230
(2007/10/02)
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