- Pressure Effects on the Thermal Decomposition of Nitramines, Nitrosamines, and Nitrate Esters
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Solutions of nitramine and nitrate ester explosives and model compounds were thermolyzed at various hydrostatic pressures and their rates of decomposition were measured.The effects of pressure on their rates were used to infer the mechanism of their initi
- Naud, Darren L.,Brower, Kay R.
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- Synthesis and characterization of novel fluorescent compounds derived from 1,4-diethyl-1,2,3,4-tetrahydro-6-nitroquinoxaline
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(Chemical Equation Presented) 1,4-Diethyl-1,2,3,4-tetrahydro-6- nitroquinoxaline 4 was synthesized by alkylative reduction of 6-nitroquinoxaline. Catalytic reduction of 4 followed by cyclocondensation with heterocyclic malondialdehydes afforded novel 8-(heteroaryl)-1,4-diethyl-1,2,3,4- tetrahydropyrido[2,3-g]quinoxalines. The solutions of these novel compounds having 1,4-diethyl-1,2,3,4-tetrahydroquinoxaline framework as an electron releasing system showed absorption in the range of 424-426 nm in the visible region and exhibited brilliant bluish-green fluorescence. The thermogravimetric curve obtained by thermogravimetric analysis displayed that these fluorophores possess excellent thermal stability with one-step thermal decomposition.
- Satam, Vijay S.,Rajule, Rajkumar N.,Jagtap, Amit R.,Bendre, Samir R.,Pati, Hari N.,Kanetkar, Vinod R.
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- Synthesis, biological evaluation, and in silico studies of new acetylcholinesterase inhibitors based on quinoxaline scaffold
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A quinoxaline scaffold exhibits various bioactivities in pharmacotherapeutic interests. In this research, twelve quinoxaline derivatives were synthesized and evaluated as new acetyl-cholinesterase inhibitors. We found all compounds showed potent inhibitory activity against acetyl-cholinesterase (AChE) with IC50 values of 0.077 to 50.080 μM, along with promising predicted drug-likeness and blood–brain barrier (BBB) permeation. In addition, potent butyrylcholinesterase (BChE) inhibitory activity with IC50 values of 14.91 to 60.95 μM was observed in some compounds. Enzyme kinetic study revealed the most potent compound (6c) as a mixed-type AChE inhibitor. No cytotoxicity from the quinoxaline derivatives was noticed in the human neuroblastoma cell line (SHSY5Y). In silico study suggested the compounds preferred the peripheral anionic site (PAS) to the catalytic anionic site (CAS), which was different from AChE inhibitors (tacrine and galanthamine). We had proposed the molecular design guided for quinoxaline derivatives targeting the PAS site. Therefore, the quinoxaline derivatives could offer the lead for the newly developed candidate as potential acetylcholinesterase inhibitors.
- Khongkow, Pasarat,Lomlim, Luelak,Nualnoi, Teerapat,Saetang, Jirakrit,Suwanhom, Paptawan,Tipmanee, Varomyalin
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- Thiazolo[5,4-f]quinoxalines, Oxazolo[5,4-f]quinoxalines and Pyrazino[b,e]isatins: Synthesis from 6-Aminoquinoxalines and Properties
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The regioselective iodination of different 2-mono-, 3-mono- and 2,3-disubstituted 6-aminoquinoxalines, which takes place at their 5-position, was rationalized on the basis of Hückel theory calculations. Oxazolo- and thiazolo[5,4-f]quinoxaline analogues of
- Bach, Stéphane,Dorcet, Vincent,El Osmani, Nour,Erb, William,Fajloun, Ziad,Lassagne, Frédéric,Mongin, Florence,Mongin, Olivier,Picot, Laurent,Richy, Nicolas,Robert, Thomas,Roisnel, Thierry,Sims, Joshua M.,Thiéry, Valérie
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supporting information
p. 2756 - 2763
(2021/06/25)
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- Photochemistry of Heteroleptic 1,4,5,8-Tetraazaphenanthrene- And Bi-1,2,3-triazolyl-Containing Ruthenium(II) Complexes
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Diimine metal complexes have significant relevance in the development of photodynamic therapy (PDT) and photoactivated chemotherapy (PACT) applications. In particular, complexes of the TAP ligand (1,4,5,8-tetraazaphenanthrene) are known to lead to photoinduced oxidation of DNA, while TAP- and triazole-based complexes are also known to undergo photochemical ligand release processes relevant to PACT. The photophysical and photochemical properties of heteroleptic complexes [Ru(TAP)n(btz)3-n]2+ (btz = 1,1′-dibenzyl-4,4′-bi-1,2,3-triazolyl, n = 1 (1), 2 (2)) have been explored. Upon irradiation in acetonitrile, 1 displays analogous photochemistry to that previously observed for [Ru(bpy)(btz)2]2+ (bpy = 2,2′-bipyridyl) and generates trans-[Ru(TAP)(btz)(NCMe)2]2+ (5), which has been crystallographically characterized, with the observation of the ligand-loss intermediate trans-[Ru(TAP)(κ2-btz)(κ1-btz)(NCMe)]2+ (4). Complex 2 displays more complicated photochemical behavior with not only preferential photorelease of btz to form cis-[Ru(TAP)2(NCMe)2]2+ (6) but also competitive photorelease of TAP to form 5. Free TAP is then taken up by 6 to form [Ru(TAP)3]2+ (3) with the proportion of 5 and 3 observed to progressively increase during prolonged photolysis. Data suggest a complex set of reversible photochemical ligand scrambling processes in which 2 and 3 are interconverted. Computational DFT calculations have enabled optimization of geometries of the pro-trans 3MCcis states with repelled btz or TAP ligands crucial for the formation of 5 from 1 and 2, respectively, lending weight to recent evidence that such 3MCcis states play an important mechanistic role in the rich photoreactivity of Ru(II) diimine complexes.
- Ashton, Gage P.,Boota, Rayhaan Z.,Elliott, Paul I. P.,Hardman, Samantha J. O.,Rice, Craig R.,Scattergood, Paul A.
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p. 15768 - 15781
(2021/10/26)
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- Metal-free regioselective nitration of quinoxalin-2(1H)-ones withtert-butyl nitrite
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A metal-free coupling of quinoxalin-2(1H)-ones withtert-butyl nitrite has been developed. Distinctly from the previous functionalization of quinoxalin-2(1H)-ones, this nitration reaction took place selectively at the C7 or C5 position of the phenyl ring, affording a series of 7-nitro and 5-nitro quinoxalin-2(1H)-ones in moderate to good yields. Preliminary mechanistic studies revealed that the reaction may involve a radical process.
- Guo, Yu,Jiang, Hong,Li, Xue-Lin,Li, Yi-Na,Liu, Yunmei,Wang, Zhen,Wu, Jin-Bo,Zeng, Yao-Fu
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supporting information
p. 10554 - 10559
(2021/12/27)
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- Compound used as EGFR kinase inhibitor and application thereof
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The invention relates to a compound used as an EGFR kinase inhibitor and application thereof, the compound has a structure as shown in a formula I, and the compound can be used for adjusting EGFR kinase activity or treating related diseases, especially non-small cell lung cancer.
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Paragraph 0422; 0425; 0445-0447
(2021/05/22)
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- ARYL-PHOSPHORUS-OXYGEN COMPOUND AS EGFR KINASE INHIBITOR
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Disclosed is a class of new aryl-phosphorus-oxygen compounds as shown in formula (I) as EGFR kinase inhibitors, and pharmaceutically acceptable salts thereof.
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Paragraph 0282; 0283
(2020/06/16)
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- Organocatalytic Green Approach Towards the Fabrication of Fused Benzo N,N-containing Heterocycles Facilitated by Ultrasonic Irradiation
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The development of a metal-free protocol for transformations in organic synthesis offers a significant potential environmental benefit. This article reports the exploration of meglumine, a nontoxic and biodegradable amino sugar, as an organocatalyst for the synthesis of biologically active 1H-dibenzo[b,e][1,4]diazepin-1-ones, highly regioselective benzimidazole derivatives and derivatives of quinoxalines. Operational simplicity, mild reaction conditions, shorter reaction times, and use of green solvents are the highlights of this protocol. The advantage of ultrasonic irradiation has been significantly explored for the synthesis of the aforesaid compounds. Furthermore, the multifaceted use of o-phenylenediamine has also been accentuated in the study.
- Nongrum, Ridaphun,Kharmawlong, George Kupar,Rani, Jims World Star,Rahman, Noimur,Dutta, Arup,Nongkhlaw, Rishanlang
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- Meta C-H Arylation of Electron-Rich Arenes: Reversing the Conventional Site Selectivity
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Controlling site selectivity of C-H activation without using a directing group remains a significant challenge. While Pd(II) catalysts modulated by a mutually repulsive pyridine-type ligand have been shown to favor the relatively electron-rich carbon centers of arenes, reversing the selectivity to favor palladation at the relatively electron-deficient positions has not been possible. Herein we report the first catalytic system that effectively performs meta C-H arylation of a variety of alkoxy aromatics including 2,3-dihydrobenzofuran and chromane with exclusive meta site selectivity, thus reversing the conventional site selectivity governed by native electronic effects. The identification of an effective ligand and modified norbornene (NBE-CO2Me), as well as taking advantage of the statistics, are essential for achieving the exclusive meta selectivity.
- Liu, Luo-Yan,Qiao, Jennifer X.,Yeung, Kap-Sun,Ewing, William R.,Yu, Jin-Quan
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supporting information
p. 14870 - 14877
(2019/10/02)
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- New 6-Aminoquinoxaline Derivatives with Neuroprotective Effect on Dopaminergic Neurons in Cellular and Animal Parkinson Disease Models
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Parkinson's disease (PD) is a neurodegenerative disorder of aging characterized by motor symptoms that result from the loss of midbrain dopamine neurons and the disruption of dopamine-mediated neurotransmission. There is currently no curative treatment for this disorder. To discover druggable neuroprotective compounds for dopamine neurons, we have designed and synthesized a second-generation of quinoxaline-derived molecules based on structure-activity relationship studies, which led previously to the discovery of our first neuroprotective brain penetrant hit compound MPAQ (5c). Neuroprotection assessment in PD cellular models of our newly synthesized quinoxaline-derived compounds has led to the selection of a better hit compound, PAQ (4c). Extensive in vitro characterization of 4c showed that its neuroprotective action is partially attributable to the activation of reticulum endoplasmic ryanodine receptor channels. Most interestingly, 4c was able to attenuate neurodegeneration in a mouse model of PD, making this compound an interesting drug candidate for the treatment of this disorder.
- Le Douaron, Gael,Ferrié, Laurent,Sepulveda-Diaz, Julia E.,Amar, Majid,Harfouche, Abha,Séon-Méniel, Blandine,Raisman-Vozari, Rita,Michel, Patrick P.,Figadère, Bruno
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p. 6169 - 6186
(2016/07/26)
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- 6- endo -dig Cycloisomerization of N -Propargyl Aminoquinoxalines: A New Route to 1,4,8-Triazaphenanthrenes
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We report the preparation of novel 1,4,8-triazaphenanthrenes and show that the target compounds are efficiently obtained from the corresponding 6-aminoquinoxalines after N-propargylation followed by copper-catalyzed 6-endo-dig cycloisomerization and aroma
- Vallerotto, Sara,Douaron, Gael Le,Bernadat, Guillaume,Ferrié, Laurent,Figadère, Bruno
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p. 3232 - 3240
(2016/09/12)
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- Aqueous hydrofluoric acid catalyzed facile synthesis of 2,3,6-substituted quinoxalines
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A versatile synthetic route for the preparation of 2,3,6-trisubstituted quinoxalines in excellent yield is developed from θ-diamines and 1,2-dicarbonyl compounds in which aqueous hydrofluoric acid was employed as the medium and catalyst. Other salient features of this protocol include milder conditions, absence of coupling agents, and easy workup procedures.
- Chandra Shekhar,Ravi Kumar,Sathaiah,Raju,Srinivas,Shanthan Rao,Narsaiah
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p. 1504 - 1508
(2015/04/27)
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- ANTIVIRAL COMPOUNDS
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The present invention relates to a compound of formula: (I) or a pharmaceutically acceptable salt thereof, wherein the symbols are as defined in the specification; a pharmaceutical composition comprising the same, a method for treating or preventing a viral infection such as HIV using the same.
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Paragraph 0169
(2013/03/26)
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- HETEROARYL COMPOUNDS AND METHODS OF USE THEREOF
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Provided herein are heteroaryl compounds, methods of their synthesis, pharmaceutical compositions comprising the compounds, and methods of their use. In one embodiment, the compounds provided herein are useful for the treatment, prevention, and/or management of various disorders, such as CNS disorders and metabolic disorders, including, but not limited to, e.g., neurological disorders, psychosis, schizophrenia, obesity, and diabetes.
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Page/Page column 43
(2012/07/27)
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- Biomass into chemicals: One-pot two- and three-step synthesis of quinoxalines from biomass-derived glycols and 1,2-dinitrobenzene derivatives using supported gold nanoparticles as catalysts
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An efficient and selective one-pot two-step method, for the synthesis of quinoxalines by oxidative coupling of vicinal diols with 1,2-phenylenediamine derivatives, has been developed by using gold nanoparticles supported on nanoparticulated ceria (Au/CeO2) or hydrotalcite (Au/HT) as catalysts and air as oxidant, in the absence of any homogeneous base. Reaction kinetics shows that the reaction controlling step is the oxidation of the diol to α-hydroxycarbonyl compound. Furthermore, a one-pot three-step synthesis of 2-methylquinoxaline starting from 1,2-dinitrobenzene and 1,2-propanediol has been successfully carried out with 98% conversion and 83% global yield to the final product.
- Climent,Corma,Hernandez,Hungria,Iborra,Martinez-Silvestre
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experimental part
p. 118 - 129
(2012/10/08)
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- HETEROCYCLIC DERIVATIVES THAT ARE USED IN THE TREATMENT OF NEURODEGENERATIVE DISEASES
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The present invention relates to compounds of Formula (I) below, to their pharmaceutically acceptable salts and to their isomers or mixtures of isomers: HetAr—X—CHR1R2 (I) in which: -HetAr represents a group chosen from: —X represents a linear, saturated or unsaturated, hydrocarbon-based chain comprising from 8 to 22 carbon atoms, optionally interrupted by an —NH— or —NH—CO— group, —R1 represents a hydrogen atom or an —OH, —O(C1-C6)alkyl, —OCO((C1-C6)alkyl), —OSO2((C1-C6)alkyl) or —OSO3H group, and —R2 represents a hydrogen atom or a (C2-C6)alkynyl, (C2-C6)alkenyl or (C3-C6)cycloalkyl group. The present invention also relates to a process for preparing the compounds of Formula (I), and also to the use thereof, especially in the treatment of neurodegenerative diseases.
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Page/Page column 7-8
(2011/06/10)
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- Nano-TiO2: An eco-friendly alternative for the synthesis of quinoxalines
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Nano-TiO2 as an eco-friendly and efficient nanocatalyst was applied for quinoxaline preparation with improved yield. In this protocol, diketones and 1,2-diamines were condensed in the presence of catalyst at room temperature.
- Mirjalili, Bi Bi Fatemeh,Akbari, Ali
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experimental part
p. 753 - 756
(2012/01/05)
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- Quaternarized pdppz: Synthesis, DNA-binding and biological studies of a novel dppz derivative that causes cellular death upon light irradiation
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The quaternarized pdppz derivative 1 was shown to bind strongly to DNA with concomitant changes in its ground and excited state photophysical properties. Furthermore, the compound also showed rapid cellular uptake, and induced apoptosis upon light irradiation in various cancer cell lines after 24 hours of incubation. The Royal Society of Chemistry 2011.
- Elmes, Robert B. P.,Erby, Marialuisa,Cloonan, Suzanne M.,Quinn, Susan J.,Williams, D. Clive,Gunnlaugsson, Thorfinnur
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supporting information; experimental part
p. 686 - 688
(2011/03/21)
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- Fluorescent sensing of anions using a bis-quinoxaline amidothiourea based supramolecular cleft; an example of an anion-induced deprotonation event
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The quinoxaline 1, possessing a 2,6-pyridyl-based amidothiourea moiety, with the view of forming a pre-organised molecular cleft, was developed as a fluorescent anion sensor. The sensing ability of 1 was evaluated in organic solution where both the ground and the excited state of 1 was affected upon recognition of anions such as acetate [as tetrabutylammonium salt (TBAAc) solution] at the amiodothiourea moieties in MeCN. The fluorescence of 1, with λmax at 477 nm, was, on all occasions quenched, upon anion recognition. Using TBAOH, we also show that the same anion-induced changes occurred; demonstrating that for this particular sensor, the anion-sensing takes place via a deprotonation mechanism. This anion-induced deprotonation event was further investigated by carrying out 1H NMR titrations on 1, using both AcO- and OH- in DMSO-d6.
- Duke, Rebecca M.,Gunnlaugsson, Thorfinnur
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body text
p. 5402 - 5405
(2010/11/02)
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- Novel nitroheterocyclic hypoxic markers for solid tumor: Synthesis and biological evaluation
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Based on the principle that the nitro-group can quench the fluorescence and can be reduced under hypoxic conditions, several novel nitroheterocyclic compounds without 2-nitroimidazole as potential hypoxic markers were prepared. Although they were synthesized from the same matrix, nitrosubstituted acenaphtho[1,2-b]quinoxaline, these compounds exhibited quite different fluorescence changes when they were differently nitrosubstituted. Their evaluation for imaging tumor hypoxia was carried out in V79 cells in vitro by Fluorescence Microplate Reader. After 3.5 h, the hypoxic-oxic fluorescence differential incubated with A1, A4, and A5 in V79 cells could reach 6, 9, and 11 times differential fluorescence between oxic and hypoxic cells separately, which are suitable for further evaluation as probes for hypoxic cells in tumors in vivo.
- Zhu, Weiping,Dai, Min,Xu, Yufang,Qian, Xuhong
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p. 3255 - 3260
(2008/09/19)
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- Novel highly regioselective syntheses of unsymmetrical 2,3-disubstituted quinoxalines
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Non-symmetrical 2,3-disubstituted quinoxalines are not easily obtained in good yields because of the lack of regioselectivity of the Hinsberg condensation, or the large number of steps required for achieving their preparation. Two efficient methods leadin
- Hui, Xu,Schmidt, Fanny,Fakhfakh, Mohammed Akram,Franck, Xavier,Figadère, Bruno
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p. 353 - 361
(2008/03/12)
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- Synthesis and antiprotozoal activity of some new synthetic substituted quinoxalines
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A series of 29 new quinoxalines was synthesized and evaluated in vitro against several parasites (Leishmania donovani, Trypanosoma brucei brucei, and Trichomonas vaginalis). Several of them displayed interesting activities, and particularly four quinoxaline amides showed in vitro antileishmanial properties (IC50 less than 20 μM).
- Hui, Xu,Desrivot, Julie,Bories, Christian,Loiseau, Philippe M.,Franck, Xavier,Hocquemiller, Reynald,Figadere, Bruno
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p. 815 - 820
(2007/10/03)
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- INHIBITORS OF HISTONE DEACETYLASE
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The invention relates to a series of compounds useful for inhibiting histone deacetylase (HDAC) enzymatic activity. The invention also provides a method for inhibiting histone descetylase in a cell using said compounds as well as a method for treating cell proliferative diseases and conditions using said HDAC inhibitors. Further, the invention provides pharmaceutical compositions comprising the HDAC inhibiting compounds and a pharmaceutically acceptable carrier.
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Page/Page column 158
(2010/02/14)
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- A Combined Experimental and Theoretical Approach toward the Development of Optimized Luminescent Carbostyrils
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The synthesis and photophysical data of new carbostyrils (quinoline-2(1H)-ones) with the longest hitherto observed absorption- and emission wavelengths are described. Introduction of 6-amino, 7-MeO, and 4-(CF3) substituents enabled us to rise the absorption and fluorescence maxima up to 414 and 557 nm, respectively. Supported by semi-empirical and ab initio calculations, the 6,7-(1,4-diazine)-fused carbostyril 23b displayed absorption maxima at up to 440 nm, with quantum yields of up to 0.9 and large Stokes shifts (> 100 nm), comparable to the best coumarin chromophores known. The new fluorophore is neither pH-sensitive between pH 6 and 10 nor susceptible to O2 quenching. At pH 3, the emitted light appears greenish-white, which arises from three different stages of protonation.
- Strohmeier, Gernot A.,Fabian, Walter M. F.,Uray, Georg
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p. 215 - 226
(2007/10/03)
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- Investigation on the photoreactions of nitrate and nitrite ions with selected azaarenes in water
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The photoreactions of selected azaarenes with nitrate and nitrite ions were investigated under irradiation at λ = 313 nm. The excitation of both anions leads to several photochemical reactions forming mainly hydroxyl radicals and nitrogen oxides. The purification capability of natural waters i.e. the oxidation of inorganic and organic substances results from the formation of hydroxyl radicals. Nitrated isomers of azaarenes were found among the main products of the investigated photoreactions. The nitrogen oxides were responsible for the production of nitrated derivatives which possess a high toxic potential. Their formation was explained by the parallel occurance of two mechanism, a molecular and a radical one. The molecular mechanism became more important with increasing ionisation potentials of the azaarenes. The spectrum of oxidized products corresponded to the one got in the photoreactions of azaarenes with hydrogen peroxide. The formation of several oxidation and nitration products of the pyridine ring with its low electron density was explained by the reaction of excited states of azaarenes. The photoreactions with nitrite ions only led to the formation of oxidized and nitrated products. Nitroso products were not formed. The reactivity of nitrogen monoxide is too low for its reaction with the azaarenes.
- Beitz, Toralf,Bechmann, Wolfgang,Mitzner, Rolf
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p. 351 - 361
(2007/10/03)
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- Design, synthesis, and photophysical characterization of novel pentacyclic red shifted azine dyes
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As part of our continuing efforts to develop second generation photodynamic therapeutic agents [1], we synthesized three pentacyclic azine dyes that were designed with the aid of MNDO calculations to absorb visible light having wavelengths longer than 600
- Gloster, Daniel F.,Cincotta, Louis,Foley, James W.
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- Elemental fluorine. Part 10.1 Selective fluorination of pyridine, quinoline and quinoxaline derivatives with fluorine-iodine mixtures
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Selective fluorination of a range of pyridine and quinoline substrates to give corresponding 2-fluoro-derivatives can be readily achieved in high yield at room temperature using elemental fluorine-iodine mixtures. Reaction of fluorine with iodine forms, in situ, systems that function like sources of both iodonium and fluoride ions and fluorination of heterocyclic derivatives is suggested to proceed by fluoride ion attack on intermediate W-iodo-heterocyclic species. Quinoxaline derivatives react under similar conditions to give either the 2-fluoro- or 2,3-difluoro-quinoxaline derivatives depending on the ratio of fluorine passed through the solution. In related processes, pyridine can be alkoxylated upon reaction of an appropriate alcohol and fluorine.
- Chambers, Richard D.,Parsons, Mandy,Sandford, Graham,Skinner, Christopher J.,Atherton, Malcolm J.,Moilliet, John S.
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p. 803 - 810
(2007/10/03)
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