- 3-HYDROXY-4'-METHOXYFLAVONE FROM MILLATTIA ZECHIANA
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3-Hydroxy-4'-methoxyflavone was identified for the first time from flowers of Millettia zechiana and its structure established from its chemical characteristics and from its synthesis.In addition known glycosides of kaempferol, quercetin, malvidin, cyanid
- Parvez, M.,Ogbeide, O. N.
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- Excited state and ground state proton transfer rates of 3-hydroxyflavone and its derivatives studied by shpol'skii spectroscopy: The influence of redistribution of electron density
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We studied the mechanisms of excited-state intramolecular proton transfer (ESIPT) and ground-state back proton transfer (BPT) in 3-hydroxyflavone (3HF) at cryogenic temperatures. The focus was on substituents that change the distribution of electronic den
- Bader, Arjen N.,Pivovarenko, Vasyl G.,Demchenko, Alexander P.,Ariese, Freek,Gooijer, Cees
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- A Fluorogenic Molecule for Probing Islet Amyloid Using Flavonoid as a Scaffold Design
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Aggregation of polypeptides and proteins is commonly associated with human and other vertebrate diseases. For example, amyloid plaques consisting of amyloid-β proteins are frequently identified in Alzheimer's disease and islet amyloid formed by islet amyloid polypeptide (IAPP, amylin) can be found in most patients with type 2 diabetes (T2D). Although many fluorescent dyes have been developed to stain amyloid fibrils, very few examples have been designed for IAPP. In this study, a series of environmentally sensitive fluorescent probes using flavonoid as a scaffold design are rationally designed and synthesized. One of these probes, namely 3-HF-ene-4′-OMe, can bind to IAPP fibrils but not nonfibrillar IAPP by exhibiting a much stronger fluorescent enhancement at 535 nm. In addition, this probe shows better detection sensitivity to IAPP fibrils compared with that of conventionally used thioflavin-T. We demonstrate that 3-HF-ene-4′-OMe can be used to monitor the kinetics of IAPP fibril formation in vitro even in the presence an amyloid inhibitor. To test the specificity of the probe, we attempt to incubate this probe with amyloid fibrils formed from other amyloidogenic proteins. Interestingly, this probe shows different responses when mixed with these fibrils, suggesting the mode of binding of this probe on these fibrils could be different. Moreover, we show that this probe is not toxic to pancreatic mouse β-cells. Further structural optimization based on the structure of 3-HF-ene-4′-OMe may yield a specific probe for imaging islet amyloid in the pancreas. That would improve our understanding of the relationship between islet amyloid and T2D.
- Chan, Ai-Ci,Chao, Yen-Cheng,Chen, Wei-Ling,Chen, Yun-Wen,Liu, Wei-Min,Ma, Shih-Ting,Tu, Ling-Hsien
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- Synchronous Fluorescence Determination of Al3+ Using 3-Hydroxy-2-(4-Methoxy Phenyl)-4H-Chromen-4-One as a Fluorescent Probe
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A simple synchronous fluorescent chemosensor 3-hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (3-HC) has been synthesized for the selective analysis of Al3+. On the addition of Al3+, 3-HC displayed a redshift with a change in wavelength of emission maximum from 436 to 465?nm along with enhancement in fluorescence intensity, which formed the basis for its sensitive detection. Under optimized conditions, 3-HC was applied for the determination of Al3+ in the concentration range of 1 × 10–7-1 × 10–6?M. The limit of detection (LOD) and limit of quantification (LOQ) values were found out to be 1.69 × 10–8 and 5.07 × 10–8?M respectively. Further, the developed method was applied for the analysis of Al3+ in real water samples (tap water, bottled water, and tube well water) which showed good recovery values in the range of 95–99.7% with RSD less than 4%.
- Bhogal, Shikha,Sharma, Promila,Rani, Pooja,Kaur, Kuldeep,Malik, Ashok Kumar
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p. 359 - 367
(2021/12/06)
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- Exploring 3-Benzyloxyflavones as new lead cholinesterase inhibitors: synthesis, structure–activity relationship and molecular modelling simulations
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In this protocol, a series of 3-benzyloxyflavone derivatives have been designed, synthesized, characterized and investigated in?vitro as cholinesterase inhibitors. The findings showed that all the synthesized target compounds (1–10) are potent dual inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes with varying IC50 values. In comparison, they are more active against AChE than BChE. Remarkably, amongst the series, the compound 2 was identified as the most active inhibitor of both AChE (IC50 = 0.05 ± 0.01 μM) and BChE (IC50 = 0.09 ± 0.02 μM) relative to the standard Donepezil (IC50 = 0.09 ± 0.01 for AChE and 0.13 ± 0.04 μM for BChE). Moreover, the derivatives 5 (IC50 = 0.07 ± 0.02 μM) and 10 (0.08 ± 0.02 μM) exhibited the highest selective inhibition against AChE as compared to the standard. Preliminary structure-activity relationship was established and thus found that cholinesterase inhibitory activities of these compounds are highly dependent on the nature and position of various substituents on Ring-B of the 3-Benzyloxyflavone scaffolds. In order to find out the nature of binding interactions of the compounds and active sites of the enzymes, molecular docking studies were carried out. (Figure presented.) HIGHLIGHTS 3-benzyloxyflavone analogues were designed, synthesized and characterized. The target molecules (1–10) were evaluated for their inhibitory potential against AChE and BChE inhibitory activities. Limited structure-activity relationship was developed based on the different substituent patterns on aryl part. Molecular docking studies were conducted to correlate the in?vitro results and to identify possible mode of interactions at the active pocket site of the enzyme. Communicated by Ramaswamy H. Sarma.
- Mughal, Ehsan Ullah,Sadiq, Amina,Ayub, Momna,Naeem, Nafeesa,Javid, Asif,Sumrra, Sajjad Hussain,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Malik, Fouzia Perveen,Ahmed, Ishtiaq
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p. 6154 - 6167
(2020/08/10)
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- Exploring 3-hydroxyflavone scaffolds as mushroom tyrosinase inhibitors: synthesis, X-ray crystallography, antimicrobial, fluorescence behaviour, structure-activity relationship and molecular modelling studies
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To explore new scaffolds as tyrosinase enzyme inhibitors remain an interesting goal in the drug discovery and development. In due course and our approach to synthesize bioactive compounds, a series of varyingly substituted 3-hydroxyflavone derivatives (1-23) were synthesized in one-pot reaction and screened for in?vitro against mushroom tyrosinase enzyme. The structures of newly synthesized compounds were unambiguously corroborated by usual spectroscopic techniques (FTIR, UV-Vis, 1H-, 13C-NMR) and mass spectrometry (EI-MS). The structure of compound 15 was also characterized by X-ray diffraction analysis. Furthermore, the synthesized compounds (1-23) were evaluated for their antimicrobial potential. Biological studies exhibit pretty good activity against most of the bacterial-fungal strains and their activity is comparable to those of commercially available antibiotics i.e. Cefixime and Clotrimazole. Amongst the series, the compounds 2, 4, 5, 6, 7, 10, 11, 14 and 22 exhibited excellent inhibitory activity against tyrosinase, even better than standard compound. Remarkably, the compound 2 (IC50 = 0.280 ± 0.010 μg/ml) was found almost sixfold and derivative 5 (IC50 = 0.230 ± 0.020 μg/ml) about sevenfold more active as compared to standard Kojic acid (IC50 =1.79 ± 0.6 μg/ml). Moreover, these synthetic compounds (1-23) displayed good to moderate activities against tested bacterial and fungal strains. Their emission behavior was also investigated in order to know their potential as fluorescent probes. The molecular modelling simulations were also performed to explore their binding interactions with active sites of the tyrosinase enzyme. Limited structure-activity relationship was established to design and develop new tyrosinase inhibitors by employing 2-arylchromone as a structural core in the future. Communicated by Ramaswamy H. Sarma.
- Ashraf, Jamshaid,Mughal, Ehsan Ullah,Sadiq, Amina,Bibi, Maryam,Naeem, Nafeesa,Ali, Anser,Massadaq, Anam,Fatima, Nighat,Javid, Asif,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Nazar, Muhammad Faizan,Mumtaz, Amara,Tahir, Muhammad Nawaz,Mirzaei, Masoud
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p. 7107 - 7122
(2020/08/21)
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- Bismuth(III) Flavonolates: The Impact of Structural Diversity on Antibacterial Activity, Mammalian Cell Viability and Cellular Uptake
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A series of homoleptic and heteroleptic bismuth(III) flavonolate complexes derived from six flavonols of varying substitution have been synthesised and structurally characterised. The complexes were evaluated for antibacterial activity towards several problematic Gram-positive (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE)) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. The cell viability of COS-7 (monkey kidney) cells treated with the bismuth flavonolates was also studied to determine the effect of the complexes on mammalian cells. The heteroleptic complexes [BiPh(L)2] (in which L=flavonolate) showed good antibacterial activity towards all of the bacteria but reduced COS-7 cell viability in a concentration-dependent manner. The homoleptic complexes [Bi(L)3] exhibited activity towards the Gram-positive bacteria and showed low toxicity towards the mammalian cell line. Bismuth uptake studies in VRE and COS-7 cells treated with the bismuth flavonolate complexes indicated that Bi accumulation is influenced by both the substitution of the flavonolate ligands and the degree of substitution at the bismuth centre.
- Burke, Kirralee J.,Stephens, Liam J.,Werrett, Melissa V.,Andrews, Philip C.
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p. 7657 - 7671
(2020/06/02)
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- Synthesis of Flavonols via Pyrrolidine Catalysis: Origins of the Selectivity for Flavonol versus Aurone
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A novel synthetic method for flavonol from 2′-hydroxyl acetophenone and benzaldehyde promoted by pyrrolidine under an aerobic condition in water is established. This protocol was supported by efficient synthesis of 44 common examples and three natural products. The α, β-unsaturated iminium ion (enimine ion E) was proved to be the key intermediate in the reaction. H218O and 18O2 isotope tracking experiments demonstrated that both water and the aerobic atmosphere were necessary to ensure the transformation. The selectivity for flavonol or aurone was originated from solvent-triggered intermediates, which were determined by UV-visible spectra from isolated enimine. The phenol-iminium E-A is dominant in water and the ketoenamine intermediate E-B is prevalent in acetonitrile. In the presence of pyrrolidine and oxygen, E-A leads to flavonol through E-I, a zwitterionic-like phenoloxyl-iminium ion, following the key steps of cyclization and a [2 + 2] oxidation; E-B proceeds through path II, a radical process induced by photolysis of E-B with both pyrrolidine and oxygen, to afford aurone. Preliminary mechanistic studies are reported.
- Xiong, Wei,Wang, Xiaohong,Shen, Xianyan,Hu, Cuifang,Wang, Xin,Wang, Fei,Zhang, Guolin,Wang, Chun
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supporting information
p. 13160 - 13176
(2020/11/23)
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- Faster and More Specific: Excited-State Intramolecular Proton Transfer-Based Dyes for High-Fidelity Dynamic Imaging of Lipid Droplets within Cells and Tissues
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Lipid droplets (LDs), a type of dynamic organelle residing at the center of cellular lipid storage, have been identified to play important roles in multiple biological processes, metabolic disorders, and diseases. The highly dynamic characters of LDs were found to correspond to their physiological and pathological functions. Hence, the fluorescent probes which enable dynamic tracking of LDs should be very helpful for better understanding the mechanisms of LDs involved biological processes and diseases. Herein we present, to the best of our knowledge, the first class of excited-state intramolecular proton transfer (ESIPT) fluorescence dyes (Flp-(11-13, 19)) for dynamic imaging of LDs based on 3-hydroxyflavone (3HF) derivatives. Flp-(11-13, 19) display strong fluorescence from yellow to NIR in lipid but exhibit almost nonfluorescence in aqueous solution. Besides, they also show large Stokes shifts (>150 nm), narrow absorption and emission peaks, and good oil-water separation efficiency, which makes them specifically target and stain LDs with very low background noisy in both living cells and fixed cells. They stain intracellular LDs quite quickly (within 30 s) with very low dosage (as low as 500 nM). Benefitting from these advantages, Flp-(11-13, 19) are applied successfully in tracking the dynamic nature of LDs and accumulation of LDs in both aqueous solution and living cells, 3D imaging of LDs for visualization of their repartition within the cells, and visualizing LDs in tissues of diseases mice models including adipose, skeletal muscle, and fatty liver tissues, underscoring the potential utility of these dyes in both LDs biology research and medical diagnosis of LDs involved diseases.
- Jiang, Gangwei,Jin, Yi,Li, Man,Liu, Changlin,Liu, Chunrong,Ren, Zhuqing,Wang, Huiling,Xiong, Mengyao,Yuan, Hong,Zeng, Weili
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p. 10342 - 10349
(2020/09/18)
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- Influence of a 4′-substituent on the efficiency of flavonol-based fluorescent indicators of β-glycosidase activity
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This article presents novel fluorescent probes, based on the excited-state intramolecular proton transfer (ESIPT) phenomenon and flavonols, sensitive to the action of specific glycosidases. 4′-Substituted flavonols were synthesized, using various approaches, and glycosylated withd-glucose,N-acetyl-d-glucosamine andd-glucuronic acid. Evaluation of the β-glycosidase activities was performed in neutral and acidic pH. In all the cases examined, an acidic environment accelerated enzymatic hydrolysis. It was demonstrated that the 4′-chloroflavonyl glycosides of all sugars tested, both in neutral and acidic pH, are the ones most sensitive to the presence of hydrolase. In turn, 4′-dimethylaminoflavonyl glucoside is not sensitive to glucosidase action at all. Generally, the rate of enzymatic hydrolysis increases as the electron-withdrawing nature of the 4′-substituent increases. An exception is the trifluoromethyl group which, in spite of having the most favourable Hammett constant, does not contribute enough to increase the rate of hydrolysis of its glucoside. The presented experimental results are supported by the electrostatic potential (ESP) analysis and related to the mechanisms of glycoside bond enzymatic hydrolysis.
- Bojarski, Piotr,Kozakiewicz, Karol,Liberek, Beata,Myszka, Henryk,Nowacki, Andrzej,Reszka, Milena,Serdiuk, Illia E.
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p. 7635 - 7648
(2020/10/14)
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- Design, synthesis, and biological evaluation of Helicobacter pylori inosine 5′-monophosphate dehydrogenase (HpIMPDH) inhibitors
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Inosine 5′-monophosphate dehydrogenase (IMPDH) catalyzes a crucial step in the biosynthesis of guanine nucleotides. Being a validated target for immunosuppressive, antiviral, and anticancer drug development, lately it has been exploited as a promising target for antimicrobial therapy. Extending our previous work on Mycobacterium tuberculosis IMPDH, GuaB2, inhibitor development, we screened a set of 23 new chemical entities (NCEs) with substituted flavone (Series 1) and 1,2,3-triazole (Series 2) core structures for their in vitro Helicobacter pylori IMPDH (HpIMPDH) and human IMPDH2 (hIMPDH2) inhibitory activities. All the NCEs possessed acceptable molecular, physicochemical, and toxicity property profiles. The ranges for HpIMPDH and hIMPDH2 inhibition were 9–99.9% and 16–57%, respectively, at 10 μM concentration. The most potent HpIMPDH inhibitor, 25c, exhibited IC50 value of 1.27 μM with no hIMPDH2 inhibitory activity. The moderately potent, structurally novel hit molecule, 25c, may serve as a lead for further design and development of highly potent HpIMPDH inhibitors.
- Sahu, Niteshkumar U.,Purushothaman, Gayathri,Thiruvenkatam, Vijay,Kharkar, Prashant S.
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p. 125 - 132
(2018/11/06)
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- Discovery of a Prenylated Flavonol Derivative as a Pin1 Inhibitor to Suppress Hepatocellular Carcinoma by Modulating MicroRNA Biogenesis
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Peptidyl-prolyl cis-trans isomerase Pin1 plays a crucial role in the development of human cancers. Recently, we have disclosed that Pin1 regulates the biogenesis of miRNA, which is aberrantly expressed in HCC and promotes HCC progression, indicating the therapeutic role of Pin1 in HCC therapy. Here, 7-(benzyloxy)-3,5-dihydroxy-2-(4-methoxyphenyl)-8-(3-methylbut-2-en-1-yl)-4H-chromen-4-one (AF-39) was identified as a novel Pin1 inhibitor. Biochemical tests indicate that AF-39 potently inhibits Pin1 activity with an IC50 values of 1.008 μm, and also displays high selectivity for Pin1 among peptidyl prolyl isomerases. Furthermore, AF-39 significantly suppresses cell proliferation of HCC cells in a dose- and time-dependent manner. Mechanistically, AF-39 regulates the subcellular distribution of XPO5 and increases miRNAs biogenesis in HCC cells. This work provides a promising lead compound for HCC treatment, highlighting the therapeutic potential of miRNA-based therapy against human cancer.
- Zheng, Yuanyuan,Pu, Wenchen,Li, Jiao,Shen, Xianyan,Zhou, Qiang,Fan, Xin,Yang, Sheng-Yong,Yu, Yamei,Chen, Qiang,Wang, Chun,Wu, Xin,Peng, Yong
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supporting information
p. 130 - 134
(2018/11/30)
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- Alkynyl Gold(I) complexes derived from 3-hydroxyflavones as multi-targeted drugs against colon cancer
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The design of multi-targeted drugs has gained considerable interest in the last decade thanks to their advantages in the treatment of different diseases, including cancer. The simultaneous inhibition of selected targets from cancerous cells to induce their death represents an attractive objective for the medicinal chemist in order to enhance the efficiency of chemotherapy. In the present work, several alkynyl gold(I) phosphane complexes derived from 3-hydroxyflavones active against three human cancer cell lines, colorectal adenocarcinoma Caco-2/TC7, breast adenocarcinoma MCF-7 and hepatocellular carcinoma HepG2, have been synthesized and characterized. Moreover, these compounds display high selective index values towards differentiated Caco-2 cells, which are considered as a model of non-cancerous cells. The antiproliferative effect of the most active complexes [Au(L2b)PPh3] (3b) and [Au(L2c)PTA] (4c) on Caco-2 cells, seems to be mediated by the inhibition of the enzyme cyclooxygenase-1/2 and alteration of the activities of the redox enzymes thioredoxin reductase and glutathione reductase. Both complexes triggered cell death by apoptosis, alterations in cell cycle progression and increased of ROS production. These results provide support for the suggestion that multi-targeting approach involving the interaction with cyclooxygenase-1/2 and the redox enzymes that increases ROS production, enhances cell death in vitro. All these results indicate that complexes [Au(L2b)PPh3] and [Au(L2c)PTA] are promising antiproliferative agents for further anticancer drug development.
- Mármol, Inés,Castellnou, Pilar,Alvarez, Raquel,Gimeno, M. Concepción,Rodríguez-Yoldi, M. Jesús,Cerrada, Elena
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- Synthesis, characterization and antimicrobial evaluation of cobalt(III) complexes of 4-(2-substituted phenylimino)-2-(4-substituted phenyl)-4H-chromen-3-ol
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A series of eight Co(III) complexes [CoL1-8(H2O)2Cl] (I-1 to I-8) incorporating 4-(2-substituted phenylimino)-2-(4-substituted phenyl)-4H-chromen-3-ol, as a tridentate imino flavone ligands (L1 to L8, 2-sub. = NH2, SH, 4-sub. = OMe, OH, Cl, NMe2) have been synthesized, characterized and the geometry of the complexes were optimized by DFT. The chemical structure of synthesized imino flavone ligands and their complexes were characterized by elemental analysis, 1H NMR, 13C NMR, UV-visible, IR, ESI-mass spectral data, conductometric and magnetic measurements. The synthesized compounds have been screened for their in vitro antibacterial activities against bacteria Vibrio cholerae, Salmonella typhi, Staphylococcus aureus, Escherichia coli and antifungal activities against fungi Candida albicans and Aspergillus flavus by paper disc diffusion method. The complexes I-3, I-4, I-7 and I-8 showed good antimicrobial activities against pathogens.
- Singh, Ashok K.,Patel, Suresh K.,Jafri, Asif
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p. 2015 - 2021
(2019/08/08)
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- Pot-economic synthesis of diarylpyrazoles and pyrimidines involving Pd-catalyzed cross-coupling of 3-trifloxychromone and triarylbismuth
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Abstract: The present study reveals the formation of 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth. The complete process encompasses two steps in the one-pot operation. The first step leads to the formation of isoflavone via cross-coupling reaction of 3-trifloxychromone and triarylbismuth as a threefold arylating reagent. These isoflavones were further converted into 3,4-diarylpyrazole and 4,5-diarylpyrimidine using hydrazine hydrate and guanidinium chloride in the successive step in the same pot. Interestingly the formation of 3,4-diarylpyrazole was achieved in the shortest reaction time i.e., 30 min that too at room temperature. Overall the developed methodology provides easy access to the medicinally important diarylpyrazole and pyrimidine moiety in one-pot operation and in short reaction time. Graphical Abstract: Synopsis The work presented here describes the novel methodology for the formation of medicinally important heterocycles 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth.
- Kumar, Abhijeet,Rao, Maddali L N
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- Ruthenium(II)-Catalyzed Synthesis of Spirobenzofuranones by a Decarbonylative Annulation Reaction
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The first decarbonylative insertion of an alkyne through C?H/C?C activation of six-membered compounds is reported. The Ru-catalyzed reaction of 3-hydroxy-2-phenyl-chromones with alkynes works most efficiently in the presence of the ligand PPh3 to provide spiro-indenebenzofuranones. Unlike previously reported metal-catalyzed decarbonylative annulation reactions, in the present decarbonylative annulation reaction, the annulation occurs before extrusion of carbon monoxide.
- Kaishap, Partha P.,Duarah, Gauri,Sarma, Bipul,Chetia, Dipak,Gogoi, Sanjib
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p. 456 - 460
(2018/02/21)
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- Synthesis, structure-activity relationship and molecular docking studies of 3-O-flavonol glycosides as cholinesterase inhibitors
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The prime objective of this research work is to prepare readily soluble synthetic analogues of naturally occurring 3-O-flavonol glycosides and then investigate the influence of various substituents on biological properties of synthetic compounds. In this context, a series of varyingly substituted 3-O-flavonol glycosides have been designed, synthesized and characterized efficiently. The structures of synthetic molecules were unambiguously corroborated by IR, 1H, 13C NMR and ESI-MS spectroscopic techniques. The structure of compound 22 was also analyzed by X-ray diffraction analysis. All the synthetic compounds (21–30) were evaluated for in vitro inhibitory potential against cholinesterase enzymes. The results displayed that most of the derivatives were potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with varying degree of IC50 values. The experimental results were further encouraged by molecular docking studies in order to explore their binding behavior with the active pocket of AChE and BChE enzymes. The experimental and theoretical results are in parallel with one another.
- Mughal, Ehsan Ullah,Javid, Asif,Sadiq, Amina,Murtaza, Shahzad,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Sumra, Sajjad Hussain,Tahir, Muhammad Nawaz,Kanwal,Khan, Khalid Mohammed
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p. 3696 - 3706
(2018/06/19)
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- An ESIPT Probe for the Ratiometric Imaging of Peroxynitrite Facilitated by Binding to Aβ-Aggregates
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A series of 3-hydroxyflavone (3-HF) ESIPT (excited-state intramolecular proton transfer) boronate-based fluorescent probes have been developed for the detection of peroxynitrite (ONOO-). The dyes are environmentally sensitive, and each probe exhibited a ratiometric response toward ONOO-in a micellar environment. The probes were used to image different aggregation states of amyloid-β (Aβ) in the presence of ONOO-. The3-HF-OMeprobe was found to produce a ratiometric response toward ONOO-when bound to Aβ aggregates, resulting in a novel host-guest ensemble, which adds insight into the development of other ESIPT-based probes for the simultaneous sensing of fibrous proteins/peptides and environmental ROS/RNS.
- Sedgwick, Adam C.,Dou, Wei-Tao,Jiao, Jin-Biao,Wu, Luling,Williams, George T.,Jenkins, A. Toby A.,Bull, Steven D.,Sessler, Jonathan L.,He, Xiao-Peng,James, Tony D.
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supporting information
p. 14267 - 14271
(2018/10/25)
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- Flavone derivatives, preparation method thereof and anticancer agent
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The present invention relates to a flavone derivative, a manufacturing method thereof and an anticancer agent including the same. Compounds represented by chemical formula 1 and chemical formula 2 according to the present invention are excellent in antica
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Paragraph 0169-0173
(2018/05/15)
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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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- Light induced carbon monoxide release molecule and preparation method thereof
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The invention discloses light induced carbon monoxide release molecules (photoCORMs) and a preparation method thereof. The photoCORMs is of modular design and is synthesized from a CO release unit, support ligand and metal zinc ions, wherein 4-MeOFLH or 4
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Paragraph 0031; 0044
(2017/11/18)
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- Antioxidant flavone analog functionalized fluorescent silica nanoparticles: Synthesis and exploration of their possible use as biomolecule sensor
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For the first time, a synthetic fluorescent antioxidant flavone analog was successfully anchored onto the surface of the APTES-modified mesoporous silica nanoparticles (NPs) through sulfonamide linkage. The surface chemistry and morphology of the flavone
- Das, Sreeparna,Batuta, Shaikh,Alam, Md. Niharul,Fouzder, Chandrani,Kundu, Rakesh,Mandal, Debabrata,Begum, Naznin Ara
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p. 286 - 296
(2017/06/13)
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- Synthesis, characterization and biological evaluation of ruthenium flavanol complexes against breast cancer
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Four Ru(II) DMSO complexes (M1R-M4R) having substituted flavones viz. 3-Hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (HL1), 3-Hydroxy-2-(4-nitrophenyl)-4H-chromen-4-one (HL2), 3-Hydroxy-2-(4-dimethylaminophenyl)-4H–chromen-4-one (HL3) and 3-Hydroxy-2-(4-chlorophenyl)-4H-chromen-4-one (HL4) were synthesized and characterized by elemental analysis, IR, UV–Vis, 1H NMR spectroscopies and ESI-MS. The molecular structures of the complexes were investigated by integrated spectroscopic and computational techniques (DFT). Both ligands as well as their complexes were screened for anticancer activities against breast cancer cell lines MCF-7. Cytotoxicity was assayed by MTT [3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. All ligands and their complexes exhibited significant cytotoxic potential of 5–40?μM concentration at incubation period of 24?h. The cell cytotoxicity increased significantly in a concentration-dependent manner. In this series of compounds, HL2 (IC50 17.2?μM) and its complex M2R (IC50 16?μM) induced the highest cytotoxicity.
- Singh, Ashok Kumar,Saxena, Gunjan,Sahabjada,Arshad
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- A facile microwave-assisted synthesis of 3-hydroxy-2-phenyl-4H-chromen-4-one and its derivatives via a novel approach
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The presented research work demonstrates a new methodology for generating a petite library of novel flavonol derivatives via Algar-Flynn-Oyamada reaction. Amongst oxygen-containing heterocycles, flavonoids are versatile scaffolds due to their manifestation as crucial components in various natural products and encompassing massive biological activities. Thus, in view of the immense significance of flavonols and the pronounced effect of microwave-assisted protocol, a systematic and efficient scheme is put together for constructing the target motive and its derivatives by both classical and novel method. Initially, 2-hydroxy chalcones are assembled through an innovative conventional technique, later followed by the formation of flavonols. This methodical protocol results in enhanced yield with reduced reaction times under benign and environmental friendly conditions. (Chemical Equation Presented).
- Ehsan, Shahana,Faisal, Saniya,Akbar, Wajiha
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p. 1190 - 1195
(2017/01/25)
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- Exploring the anti-breast cancer potential of flavonoid analogs
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In the course of our search for new antitumor agents for breast cancer, novel flavone derivatives were synthesized, characterized and examined for their antitumor activities against breast cancer cell lines. In initial screening, analogs 7a [3-(5-amino-1,3,4-thiadiazol-2-yl)methoxy-2-phenyl-4H-chromen-4-one] and 7b [3-(5-amino-1,3,4-thiadiazol-2-yl)methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one] were found to be effective against the estrogen receptor negative cell line (MDA-MB 453), which was followed by their evaluation in five dose assays. In addition, mechanistic studies of 7a and 7b were performed by cytometric analysis and electrophoretic studies and it was observed that apoptosis is a mechanism of cell death, confirmed morphologically by acridine orange/ethidium bromide double staining and TUNEL analysis. Further in vivo evaluation of the anti-tumor activity of compound 7a and 7b by Ehrlich Ascites Carcinoma (EAC) model and related studies confirms the anti-breast cancer potential of flavonoid analogs.
- Thakor, Vanrajsinh,Poddar, Mayur,Dey, Sumit,Manjula,Madhunapantula, Subbarao V.,Pawara, Rahul,Patel, Harun M.,Noolvi, Malleshappa N.
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p. 79166 - 79179
(2016/09/09)
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- Absorption and fluorescent studies of 3-hydroxychromones
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The synthesis and spectral studies of variously substituted 3-hydroxychromones have been carried out. A key relationship between the structural motif of synthesized 3-hydroxychromones (3-HCs) and their fluorescent properties was found. The chromones substituted with electron-donating group at 4′-position expressed the red shift of the N and T band and also exhibited the increased fluorescent intensity ratio while the chromones with electron-withdrawing group showed the blue shift of the N and T band. Therefore, these 3-HCs may behave as the possible fluorescent probes.
- Khanna, Radhika,Kumar, Ramesh,Dalal, Aarti,Kamboj, Ramesh C.
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p. 1159 - 1163
(2015/10/20)
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- Synthesis and effects on cell viability of flavonols and 3-methyl ether derivatives on human leukemia cells
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Flavonoids are polyphenolic compounds which display an array of biological activities and are considered potential antitumor agents. Here we evaluated the antiproliferative activity of selected synthetic flavonoids against human leukemia cell lines. We found that 4′-bromoflavonol (flavonol 3) was the most potent. This compound inhibited proliferation in a concentration-dependent manner, induced apoptosis and blocked cell cycle progression at the S phase. Cell death was found to be associated with the cleavage and activation of multiple caspases, the activation of the mitogen-activated protein kinase pathway and the up-regulation of two death receptors (death receptor 4 and death receptor 5) for tumor necrosis factor-related apoptosis-inducing ligand. Moreover, combined treatments using 4′-bromoflavonol and TRAIL led to an increased cytotoxicity compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.
- Burmistrova, Olga,Marrero, María Teresa,Estévez, Sara,Welsch, Isabel,Brouard, Ignacio,Quintana, José,Estévez, Francisco
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- Pharmacophore model of the quercetin binding site of the SIRT6 protein
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SIRT6 is a histone deacetylase that has been proposed as a potential therapeutic target for metabolic disorders and the prevention of age-associated diseases. We have previously reported on the identification of quercetin and vitexin as SIRT6 inhibitors,
- Ravichandran,Singh,Donnelly,Migliore,Johnson,Fishwick,Luke,Martin,Maudsley,Fugmann,Moaddel
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- Quantum-chemical analysis of the Algar-Flynn-Oyamada reaction mechanism
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This work is devoted to improving the understanding of Algar-Flynn-Oyamada reaction mechanism and the analysis of factors that affect the formation of flavonols. The calculation of thermodynamic parameters for the key reaction steps pointed to a mechanism involving chalcone epoxides as intermediates. A correlation was identified between the nucleophilicity of oxygen atom at position 2' of epoxide anions and the yields of flavonols. An increased charge at the nucleophilic center was shown to reduce the effectiveness of β-cyclization of epoxide anions.
- Serdiuk,Roshal,B?a?ejowski
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p. 396 - 403
(2014/08/05)
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- Superior anticancer activity of halogenated chalcones and flavonols over the natural flavonol quercetin
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A series of chalcone and flavonol derivatives were synthesized in good yield by an eco-friendly approach. A pharmacological evaluation was performed with the human colorectal carcinoma cell line HCT116 and revealed that the anticancer activity of flavonols was higher when compared with that of the respective chalcone precursors. The antiproliferative activity of halogenated derivatives increases as the substituent in the 3- or 4-positon of the B-ring goes from F to Cl and to Br. In addition, halogens in position 3 enhance anticancer activity in chalcones whereas for flavonol derivatives the best performance was registered for the 4-substituted derivatives. Flow cytometry analysis showed that compounds 3p and 4o induced cell cycle arrest and apoptosis as demonstrated by increased S, G2/M and sub-G1 phases. These data were corroborated by western blot and fluorescence microscopy analysis. In summary, halogenated chalcones and flavonols were successfully prepared and presented high anticancer activity as shown by their cell growth and cell cycle inhibitory potential against HCT116 cells, superior to that of quercetin, used as a positive control.
- Dias, Tatiana A.,Duarte, Cecília L.,Lima, Cristovao F.,Proen?a, M. Fernanda,Pereira-Wilson, Cristina
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p. 500 - 510
(2013/10/01)
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- Synthesis and biological evaluation of flavones and benzoflavones as inhibitors of BCRP/ABCG2
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Multidrug resistance (MDR) often leads to a failure of cancer chemotherapy. Breast Cancer Resistance Protein (BCRP/ABCG2), a member of the superfamily of ATP binding cassette proteins has been found to confer MDR in cancer cells by transporting molecules with amphiphilic character out of the cells using energy from ATP hydrolysis. Inhibiting BCRP can be a solution to overcome MDR.We synthesized a series of flavones, 7,8-benzofl avones and 5,6-benzo flavones with varying substituents at positions 3, 3′ and 4′ of the (benzo)fl avone structure. All synthesized compounds were tested for BCRP inhibition in Hoechst 33342 and pheophorbide A accumulation assays using MDCK cells expressing BCRP. All the compounds were further screened for their P-glycoprotein (P-gp) and Multidrug resistance-associated protein 1 (MRP1) inhibitory activity by calcein AM accumulation assay to check the selectivity towards BCRP. In addition most active compounds were investigated for their cytotoxicity. It was observed that in most cases 7,8-benzoflavones are more potent in comparison to the 5,6-benzoflavones. In general it was found that presence of a 3-OCH3 substituent leads to increase in activity in comparison to presence of OH or no substitution at position 3. Also, it was found that presence of 3′,4′-OCH3 on phenyl ring lead to increase in activity as compared to other substituents. Compound 24, a 7,8-benzoflavone derivative was found to be most potent being 50 times selective for BCRP and showing very low cytotoxicity at higher concentrations.
- Juvale, Kapil,Stefan, Katja,Wiese, Michael
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p. 115 - 126
(2013/10/01)
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- An expeditious synthesis of flavonols promoted by montmorillonite KSF clay and assisted by microwave irradiation under solvent-free conditions
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A simple, efficient, rapid, and ecofriendly synthesis of flavonols in >90% yield from 2′-(mesyloxy)epoxychalcones (=2-(3-aryl-2,3- epoxypropanoyl)phenyl methanesulfonates) promoted by montmorillonite KSF clay and assisted by microwave irradiation has been described. Copyright
- Babu, Mariappan,Pitchumani, Kasi,Ramesh, Penugonda
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p. 1269 - 1272
(2013/08/23)
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- Boron difluoride complexes of 3-hydroxyflavone derivatives: Efficient bioinspired dyes for solution and solid-state emission
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A series of six boron difluoride complexes of 3-hydroxyflavone derivatives is described. These dyes were synthesized very simply and exhibited bright visible emission in solution (up to unity) as well as emission in the solid state. Complexation to boron difluoride was shown to impart donor-acceptor character to the excited state of these dyes, which further shifted the emission towards the visible part of the spectrum. Furthermore, differences were noticed following the strength of the donor and the acceptor. Light emission from the π-stacked molecules was quenched relative to the solution behaviour which was interpreted in terms of both packing and electronic properties of the molecular dyes. The packing arrangement was found to be a function of the substituent on the 3-hydroxyflavone derivatives.
- D'Aleo, Anthony,Fages, Frederic
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p. 500 - 510
(2013/06/05)
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- Synthesis and biological evaluation of novel flavonols as potential anti-prostate cancer agents
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A library of flavonol analogues was synthesised and evaluated as potential anticancer agents against a human prostate cancer cell line, 22rν1. Compounds 3, 8 and 11 (IC50 2.6, 3.3 and 4.0 μM respectively) showed potent cancer cell growth inhibi
- Britton, Robert G.,Horner-Glister, Emma,Pomenya, Odette A.,Smith, Ewan E.,Denton, Roanne,Jenkins, Paul R.,Steward, William P.,Brown, Karen,Gescher, Andreas,Sale, Stewart
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p. 952 - 958
(2012/10/08)
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- Total synthesis of 3′,3?-binaringenin and related biflavonoids
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The synthesis of natural 3++,3?-binaringenin and four related biflavonoids was performed in good overall yield (15-35%) starting from readily available phloroglucinol and 4-hydroxy- or 4-methoxybenzaldehyde. Preliminary results indicate that some of these compounds have an interesting activity against S. aureus. Georg Thieme Verlag Stuttgart.
- Sagrera, Gabriel,Seoane, Gustavo
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experimental part
p. 2776 - 2786
(2010/10/19)
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- Synthesis and molecular docking studies of novel 2-chloro-pyridine derivatives containing flavone moieties as potential antitumor agents
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A series of novel 2-chloro-pyridine derivatives containing flavone, chrome or dihydropyrazole moieties as potential telomerase inhibitors were synthesized. The bioassay tests showed that compounds 6e and 6f exhibited some effect against gastric cancer cell SGC-7901 with IC50 values of 22.28 ± 6.26 and 18.45 ± 2.79 μg/mL, respectively. All title compounds were assayed for telomerase inhibition by a modified TRAP assay, the results showed that compound 6e can strongly inhibit telomerase with IC50 value of 0.8 ± 0.07 μM. Docking simulation was performed to position compound 6e into the active site of telomerase (3DU6) to determine the probable binding model.
- Liu, Xin-Hua,Liu, Hui-Feng,Shen, Xu,Song, Bao-An,Bhadury, Pinaki S.,Zhu, Hai-Liang,Liu, Jin-Xing,Qi, Xing-Bao
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scheme or table
p. 4163 - 4167
(2010/08/20)
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- Synthesis of a library of glycosylated flavonols
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Flavonols are an important class of natural products isolated from plants. Some glycosylated flavonols showed very interesting biological activities. A library of flavonols has been made through Algar-Flynn-Oyamada reaction from 2′-hydroxyacetophenones an
- Li, Zhitao,Ngojeh, George,DeWitt, Paul,Zheng, Zhi,Chen, Min,Lainhart, Brendan,Li, Vincent,Felpo, Peter
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scheme or table
p. 7243 - 7245
(2009/04/11)
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- Understanding the cardioprotective effects of flavonols: Discovery of relaxant flavonols without antioxidant activity
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3′,4′-Dihydroxyflavonol (DiOHF) is a cardioprotective flavonol that can reduce injury after myocardial ischemia and reperfusion and thus is a promising small molecule for the treatment of cardiovascular disease. Like all vasoactive flavonols reported to date, DiOHF is both relaxant and antioxidant, hindering investigation of the relative contribution of each activity for the prevention of reperfusion injury. This study investigates structure-activity relationships of variations at the 3′ and 4′ positions of the B ring of DiOHF and vasorelaxant and antioxidant activities. Relaxation of rat isolated aortic rings precontracted with KCl revealed that the most active flavonols were those with a 4′-hydroxyl group, with the opening of potassium channels as a possible contributing mechanism. For the antioxidant activity, with the exception of DiOHF, none of the flavonols investigated were able to significantly scavenge superoxide radical, and none of the three most potent vasorelaxant flavonols could prevent oxidant-induced endothelial dysfunction. The discovery of single-acting vasorelaxant flavonols without antioxidant activity, in particular 4′-hydroxy-3′-methoxyflavonol, will assist in investigating the mechanism of flavonol-induced cardioprotection.
- Cheng, Xue Qin,Chen, Xingqiang,Hughes, Richard A.,Williams, Spencer J.,Woodman, Owen L.
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p. 1874 - 1884
(2008/12/21)
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- COMPOUNDS FOR IMMUNOPOTENTIATION
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Methods of stimulating an immune response and treating patients responsive thereto with 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5-diones, staurosporine analogs, derivatized pyridazines, chromen-4-ones, indolinones, quinazolines, nucleoside analogs, and other small molecules are disclosed.
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Page/Page column 121
(2010/02/15)
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- CDK inhibitors having flavone structure
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The present invention relates to a novel flavone derivative, pharmaceutically acceptable salt, hydrate, solvate and isomer thereof which is useful as an inhibitor against Cyclin Dependent Kinase (CDK), a process for preparation thereof, and a composition of anti-cancer agent or agent for treating neurodegenerative disease comprising this compound as an active ingredient.
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- Effect of flavonol derivatives on the carrageenin-induced paw edema in the rat and inhibition of cyclooxygenase-1 and 5-lipoxygenase in vitro.
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Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chr
- Sobottka,Werner,Blaschke,Kiefer,Nowe,Dannhardt,Schapoval,Schenkel,Scriba
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p. 205 - 210
(2007/10/03)
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- Design and synthesis of a novel series of nonpeptidic HIV-1 protease inhibitors
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Using molecular modelling and the X-ray crystal structures of peptide, (1-(naphthoxy-acetyl)-L-histidyl-5(S)-amino-6-cyclohexyl-3 (R),4(R)-dihydroxy-2(R)-isopropylhexanoyl-L-isoleucine N-(2-pyridylmethyl)amide (U-75875) and nonpeptide-derived inhibitors,
- Hariprasad,Talele,Kulkarni, Vithal M.
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p. 365 - 372
(2007/10/03)
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- Synthesis and cyclization of 1-(2-hydroxyphenyl)-2-propen-1-one epoxides: 3-Hydroxychromanones and -flavanones versus 2-(1-hydroxyalkyl)-3-coumaranones
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Competitive α and β cyclization of 2'-hydroxychalcone epoxides affords 2-(α-hydroxybenzyl)-3-coumaranone and/or 3-hydroxyflavanones, which depends on the conditions employed. Epoxidation of 2'-hydroxychalcones by dimethyldioxirane followed by either base- or acid-catalyzed ring closure provides a novel, general, and efficient method for the synthesis of trans-3-hydroxyflavanones, which includes also the naturally occurring derivatives. Extension of this two-step procedure to 1-(2-hydroxyphenyl)-2-alken-1-ones was also accomplished. A strong preference for α cyclization was observed in the case of β-unsubstituted or -monoalkylated α,β-enones, while both 2,2-dimethyl-3-hydroxychromanones and 2-(1-hydroxy-1-methylethyl)-3-coumaranones were obtained from the β,β-dimethylated substrates.
- Patonay, Tamas,Levai, Albert,Nemes, Csaba,Timar, Tibor,Toth, Gabor,Adam, Waldemar
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p. 5375 - 5383
(2007/10/03)
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- C-3 Hydroxylation of flavones using hypervalent iodine oxidation
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Hypervalent iodine oxidation of several flavones (1b-g) with iodobenzene diacetate in methanolic potassium hydroxide, followed by acid hydrolysis of the resultant 3-hydroxy-2-methoxyflavonones dimethylacetals (2b-g), offers a general method for 3-hydroxyflavones (3b-g).
- Prakash, Om,Pahuja, Saroj,Tanwar, Madan P
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p. 272 - 273
(2007/10/02)
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- Flavonoids. 43. Deprotonation-initiated Aryl Migration with Sulfur Dioxide Extrusion: A Route to 2,3-Dihydro-2,3-diaryl-3-hydroxy-4H-1-benzopyran-4-ones
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Treatment of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with various bases afforded 2,3-dihydro-r-2-aryl-t-3-hydroxy-c-3-(4-nitrophenyl)-4H-1-benzopyran-4-ones in a deprotonation-initiated aryl migration followed by sulfur dioxide extrusion.In the presence of hydroxide and methoxide ions a secondary ring cleavage has also been observed.However, the reaction of trans-2,3-dihydro-2-aryl-3-nosyloxy-4H-1-benzopyran-4-ones with cyanide ions gave 2,3-dihydro-r-2-aryl-t-4-cyano-c-3,c-4-epoxy-4H-1-benzopyrans in a carbonyl attack of cyanide followed by an internal substitution reaction.
- Patonay, Tamas,Hegedues, Laszlo,Patonay-Peli, Erzsebet
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p. 145 - 151
(2007/10/02)
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- FLAVONOIDS, 40. SYNTHESIS OF 3-ALKYL- AND -ARYLTHIOFLAVANONES AND THEIR TRANSFORMATIONS INTO SULFUR-CONTAINING FLAVONOIDS
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trans-3-Mesyloxyflavanones 1 were converted into cis- and trans-3-(alkylthio)- and -(phenylthio)flavanones 2-4 by nucleophilic substitution reaction with thiols or thiolates.Flavanones 2-4 were useful intermediates in the synthesis of various sulfur-containing derivatives; flavanones, flavones and dihydrochalcones posessing alkyl- or arylthio, -sulfinyl and -sulfonyl group.Oxidation of cis- and trans- isomers of 4 led to completely different products.
- Patonay, Tamas,Patonay-Peli, Erzsebet,Litkei, Gyoergy
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p. 1827 - 1834
(2007/10/02)
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- REACTION OF POTASSIUM SUPEROXIDE WITH 3-NITRO-2-PHENYL-2H-1-BENZOPYRANS AND THEIR DIHYDRO DERIVATIVES
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3-Nitro-2-phenyl-2H-1-benzopyrans on treatment with potassium superoxide in dimethyl sulphoxide are degraded mainly to the corresponding salicylic acids and benzoic acids. Formation of flavonols, as a minor product are also observed. The dihydro derivatives of 3-nitro-2-phenyl-2H-1-benzopyrans are converted to the corresponding flavonols by potassium superoxide in benzene containing 18-crown-6 ether.
- Rao, Takkellapati Sudhakar,Trivedi, Girish Kumar
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p. 2117 - 2124
(2007/10/02)
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- A NOVEL PHOTOCHEMICAL METHOD FOR THE SYNTHESIS OF FLAVONOLS
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Photolysis of the nitrochromenes followed by acidic hydrolysis of the photoproducts yields the corresponding flavonols in high yields.
- Rao, Sudhakar T.,Singh, Anil Kumar,Trivedi, Girish Kumar
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p. 1377 - 1382
(2007/10/02)
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- REACTION OF CHROMOUS CHLORIDE WITH 3-NITROFLAVENES. A NOVEL SYNTHESIS OF FLAVONOLS
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Reaction of Chromium(II) chloride with 3-nitroflavene yields flavonol.
- Rao, T. Sudhakara,Mathur, H. H.,Trivedi, G. K.
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p. 5561 - 5562
(2007/10/02)
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