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Lingala Suresh, P Sagar Vijay Kumar, Y Poornachandra, C Ganesh Kumar, G V P Chandramouli
An efficient four-component reaction of 6-amino-1,3-dimethyluracil, N,N-dimethylformamide dimethylacetal, 1-phenyl-3-(4-substituted-phenyl)-4-formyl-1H-pyrazoles and aromatic amines was conducted in the presence of [Bmim]FeCl4 ionic liquid as a promoting medium. This strategy provided a convenient route without any additional catalyst or metal salt under mild conditions. All the synthesized pyrazolo-pyrimido[4,5-d]pyrimidines derivatives were evaluated for their antibacterial, minimum bactericidal concentration (MBC), biofilm inhibition, intracellular ROS accumulation and protein leakage activities...
February 3, 2017: Bioorganic & Medicinal Chemistry Letters
David B Lingerfelt, Patrick J Lestrange, Joseph J Radler, Samantha E Brown-Xu, Pyosang Kim, Felix N Castellano, Lin X Chen, Xiaosong Li
Materials and molecular systems exhibiting long-lived electronic coherence can facilitate coherent transport, opening the door to efficient charge and energy transport beyond traditional methods. Recently, signatures of a possible coherent, recurrent electronic motion were identified in femtosecond pump-probe spectroscopy experiments on a bi-nuclear platinum complex, where a persistent periodic beating in the transient absorption signal's anisotropy was observed. In this study, we investigate the excitonic dynamics that underlie the suspected electronic coherence for a series of bi-nuclear platinum complexes exhibiting a range of inter-platinum distances...
February 16, 2017: Journal of Physical Chemistry. A
Yun-Wu Li, Ling-Yu Guo, Hai-Feng Su, Marko Jagodič, Ming Luo, Xiao-Qi Zhou, Su-Yuan Zeng, Chen-Ho Tung, Di Sun, Lan-Sun Zheng
Two novel POM-based inorganic-organic hybrids, [Cu6(II)(2,2'-bipy)6(Mo6O22)(SiW12O40)]n (1), and {[Cu6(II)(ppz)6(H2O)5(MoO4)(SiW12O40)]·4H2O}n (2) (2,2'-bipy = 2,2'-bipyridine, Hppz = 3-(pyrid-2-yl)pyrazole), have been constructed from heteropolytungstates and molybdates. Two compounds have been identified by single crystal X-ray diffraction, elemental analysis, and FT-IR. Compound 1 shows a 1D (one-dimensional) chain structure constructed from classical Keggin heteropolytungstate [SiW12O40](4-) clusters and [Cu6(2,2'-bipy)6] modified isopolymolybdates [Mo6O22](8-)...
February 15, 2017: Inorganic Chemistry
L Marleny Rodríguez-Albelo, Elena López-Maya, Said Hamad, A Rabdel Ruiz-Salvador, Sofia Calero, Jorge A R Navarro
The widespread emissions of toxic gases from fossil fuel combustion represent major welfare risks. Here we report the improvement of the selective sulfur dioxide capture from flue gas emissions of isoreticular nickel pyrazolate metal organic frameworks through the sequential introduction of missing-linker defects and extra-framework barium cations. The results and feasibility of the defect pore engineering carried out are quantified through a combination of dynamic adsorption experiments, X-ray diffraction, electron microscopy and density functional theory calculations...
February 15, 2017: Nature Communications
Morena Zusso, Giulia Mercanti, Federica Belluti, Rita Maria Concetta Di Martino, Andrea Pagetta, Carla Marinelli, Paola Brun, Eugenio Ragazzi, Rita Lo, Stefano Stifani, Pietro Giusti, Stefano Moro
BACKGROUND AND PURPOSE: Toll-like receptor 4 (TLR4) plays a key role in the induction of inflammatory responses both in peripheral organs and the CNS. Curcumin exerts anti-inflammatory functions by interfering with LPS-induced TLR4-myeloid differentiation protein-2 (MD-2) dimerization and suppressing pro-inflammatory mediator release. However, the inhibitory mechanism of curcumin remains to be defined. EXPERIMENTAL APPROACH: Binding of bis-demethoxycurcumin (GG6) and its cyclized pyrazole analogue (GG9), which lacks the 1,3-dicarbonyl function, to TLR4-MD-2 was determined using molecular docking simulations...
February 15, 2017: British Journal of Pharmacology
Ya-Sheng Li, De-Kun Hu, Dong-Sheng Zhao, Xing-Yu Liu, Hong-Wei Jin, Gao-Peng Song, Zi-Ning Cui, Lian-Hui Zhang
In this study, a series of pyrazole derivatives containing 4-phenyl-2-oxazole moiety were designed and synthesized in a concise way, some of which exhibited considerable inhibitory activity against PDE4B and blockade of LPS-induced TNF-α release. Compound 4c displayed the strongest inhibition activity (IC50=1.6±0.4μM) and good selectivity against PDE4B. Meanwhile, compound 4c showed good in vivo activity in animal models of asthma/COPD and sepsis induced by LPS. The primary structure-activity relationship study showed the 3,5-dimethylpyrazole residue was essential for the bioactivity, and the substituted group R1 at the benzene ring also affected the activity...
February 3, 2017: Bioorganic & Medicinal Chemistry
Bin-Bin Xie, Xiang-Yang Liu, Qiu Fang, Wei-Hai Fang, Ganglong Cui
We have employed combined electronic structure calculations and nonadiabatic dynamics simulations to study the S1 radiationless deactivation mechanism of pyrazole. In terms of MS-CASPT2 computed results, we propose that the (1)πσ* state-driven nonadiabatic N-N dissociation is a major relaxation path; the ring-puckering deformation path as well as the (1)πσ* state-driven N-H dissociation are less favorable. This excited-state decay mechanism is supported by MS-CASPT2 nonadiabatic dynamics simulations. The present study demonstrates that pyrazole has a different excited-state radiationless deactivation mechanism compared with its structural isomer imidazole, in which the (1)πσ* state-driven nonadiabatic N-H dissociation plays a more important role...
February 16, 2017: Journal of Physical Chemistry Letters
Degang Liu, David Xu, Min Liu, William Eric Knabe, Cai Yuan, Donghui Zhou, Mingdong Huang, Samy O Meroueh
Protein-protein interactions drive every aspect of cell signaling, yet there exist only few small-molecule inhibitors of these interactions. Despite our ability to identify critical residues known as hot spots, little is known about how to effectively engage them to disrupt protein-protein interactions. Here, we take advantage of the ease of preparation and stability of pyrrolinone 1, a small-molecule inhibitor of the tight uPAR•uPA interaction, to synthesize more than 40 derivatives and explore their effect on the protein-protein interaction...
February 10, 2017: Biochemistry
Prasun Mukherjee, Asish R Das
A robust intramolecular cyclopropanation reaction was first performed on pyrano-pyrazole and pyrano-pyrimidine dione derivatives to obtain spiro-cyclopropyl pyrazolones and barbiturates, using iodosylbenzene (PhIO) or the combination of iodobenzene diacetate (PIDA)/ molecular iodine (I2), under mild reaction conditions. Syntheses of functionally and stereochemically diversified, novel spiropyrazolone fused 2-iminothiophene and spiropyrazolone fused pyrroline scaffolds were also demonstrated via Lewis acid catalyzed highly diastereoselective (3+2) cycloaddition reactions of the synthesized spiro-cyclopropyl pyrazolones with phenyl isothiocyanate and benzonitrile respectively...
February 9, 2017: Journal of Organic Chemistry
Lorena Santos-Bubniak, Pâmela Cristina Gaspar, Ana Carolina Rabello de Moraes, Alisson Bigolin, Rubia Karine Souza, Fátima Campos Buzzi, Rogério Correa, Valdir Cechinel Filho, Lizandra Czermainski Bretanha, Gustavo Amadeu Micke, Ricardo José Nunes, Maria Cláudia Santos-Silva
Pyrazoline is an important five-membered nitrogen heterocycle, which has been extensively researched. Ten derivatives were synthesized and tested for antileukemic effects on two human acute leukemia cell lines, K562 and Jurkat. The most cytotoxic compound 21 was chosen for investigation of cytotoxicity mechanisms. The results obtained with selectivity calculations revealed that compound 21 is more selective for acute leukemia (K562 and Jurkat cell lines) than to other tumor cell lines. Besides, compound 21 was not cytotoxic to normal cell lines, indicating a potential use in clinical tests...
November 24, 2016: Canadian Journal of Physiology and Pharmacology
Hai-Jie Liu, Marcos Gil-Sepulcre, Laia Francàs, Pau Nolis, Teodor Parella, Jordi Benet-Buchholz, Xavier Fontrodona, Jordi García-Antón, Nuria Romero, Antoni Llobet, Lluís Escriche, Roger Bofill, Xavier Sala
A new CNNC carbene-phthalazine tetradentate ligand has been synthesised, which in the reaction with [Ru(T)Cl3] (T = trpy, tpm, bpea; trpy = 2,2';6',2''-terpyridine; tpm = tris(pyrazol-1-yl)methane; bpea = N,N-bis(pyridin-2-ylmethyl)ethanamine) in MeOH or iPrOH undergoes a C-N bond scission due to the nucleophilic attack of a solvent molecule, with the subsequent formation of the mononuclear complexes cis-[Ru(PhthaPz-OR)(trpy)X](n+), [Ru(PhthaPz-OMe)(tpm)X](n+) and trans,fac-[Ru(PhthaPz-OMe)(bpea)X](n+) (X = Cl, n = 1; X = H2O, n = 2; PhthaPz-OR = 1-(4-alkoxyphthalazin-1-yl)-3-methyl-1H-imidazol-3-ium), named 1a(+)/2a(2+) (R = Me), 1b(+)/2b(2+) (R = iPr), 3(+)/4(2+) and 5(+)/6(2+), respectively...
February 8, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Zhongyan Huang, Okiya Matsubara, Shichong Jia, Etsuko Tokunaga, Norio Shibata
A novel HF2CSO2Na/Ph2PCl/Me3SiCl system is disclosed for the late-stage direct difluoromethylthiolation of Csp2 and Csp3 nucleophiles. Difluoromethylthiolation of phenols and naphthols proceeded nicely under this system to regioselectively provide corresponding SCF2H compounds in good yields. Other substrates such as indoles, pyrroles, pyrazoles, enamines, ketones, and β-keto esters were also transformed to corresponding SCF2H products in good yields. The late-stage direct difluoromethylthiolation of a number of natural products and pharmaceutically attractive molecules was also achieved...
February 6, 2017: Organic Letters
Anastasia Vogel, Sebastian Dechert, Christian Brückner, Franc Meyer
Siamese-twin porphyrin is a pyrazole-containing expanded porphyrin incorporating two porphyrin-like binding pockets. The macrocycle, however, does not possess an aromatic π system but rather two separated conjugation pathways that are isolated by the pyrazole junctions. Mono- and bimetallic complexes of the Siamese-twin porphyrin are known. This work addresses in detail the electronic consequences that monometalation (with Pd(II)) has on the electronic properties of the nonmetalated binding pocket by studying the solid-state structure, acid/base, and electrochemical properties of the monopalladium twin-porphyrin complex...
February 6, 2017: Inorganic Chemistry
Nagat Ghareb, Mohamed M Abdel Daim, Norhan M El-Sayed, Mohamed Saleh Elgawish
The synthesis, pharmacological evaluation and molecular modelling study of novel naphthalen-2-yl acetate and 1,6-dithia-4,9-diazaspiro [4.4]nonane-3,8-dione derivatives as potential anticonvulsant agents are described. The newly synthesized compounds were characterized by both analytical and spectral data. Alkylation of 1H-imidazole or substituted piperazine with 1-(2-naphthyl)-2-bromoethanone (2) gave naphthalen-2-yl 2-(1H-imidazol-1-yl) acetate (3) and naphthalen-2-yl 2-(substituted piperazin-1-yl) acetate (4-8)...
January 25, 2017: Bioorganic Chemistry
Faryal Chaudhry, Sadia Naureen, Rahila Huma, Ayesha Shaukat, Mariya Al-Rashida, Nadia Asif, Mohammad Ashraf, Munawar Ali Munawar, Misbahul Ain Khan
Under three different reaction conditions (conventional heating, microwave irradiations and amino acid catalysis), a series of imidazolylpyrazoles (2a-2k) were synthesized in good to excellent yields from a mixture of three precursors: aryl(hetaryl)pyrazole-4-carbaldehydes (1a-1k), benzil and ammonium acetate. α-Glucosidase inhibition assay revealed a new class of highly potent agents wherein each compound displayed significant inhibitory potentials (in terms of percentage inhibition and relative IC50 values) as compared to that of the reference drug (Acarbose)...
January 23, 2017: Bioorganic Chemistry
Adriane F Brito, James O Fajemiroye, Hiasmin F S Neri, Dayane M Silva, Daiany P B Silva, Germán Sanz, Boniek G Vaz, Flávio S de Carvalho, Paulo C Ghedini, Luciano M Lião, Ricardo Menegatti, Elson A Costa
In this study we proposed the design, synthesis of a new compound 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol (LQFM032), and pharmacological evaluation of its anxiolytic-like effect. This new compound was subjected to pharmacological screening refered to as Irwin test, prior to sodium pentobarbital-induced sleep, open field and wire tests. The anxiolytic-like effect of this compound was evaluated using elevated plus maze and light-dark box tests. In addition, the mnemonic activity was evaluated through step-down test...
February 3, 2017: Chemical Biology & Drug Design
Thomas R Porter, Ellen C Hayes, Werner Kaminsky, James M Mayer
The bulky 2,6-di-tert-butyl-4-nitrophenolate ligand forms complexes with [Tp(tBu)Cu(II)](+) and [Tp(tBu)Zn(II)](+) binding via the nitro group in an unusual nitronato-quinone resonance form (Tp(tBu) = hydro-tris(3-tert-butyl-pyrazol-1-yl)borate). The Cu complex in the solid state has a five-coordinate κ(2)-nitronate structure, while the Zn analogue has a four-coordinate κ(1)-nitronate ligand. 4-Nitrophenol, without the 2,6-di-tert-butyl substituents, instead binds to [Tp(tBu)Cu(II)](+) through the phenolate oxygen...
February 3, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Albert Hofstetter, Lyndon Emsley
We propose a method to quantify positional uncertainties in crystal structures determined by chemical-shift-based NMR crystallography. The method combines molecular dynamics simulations and density functional theory calculations with experimental and computational chemical shift uncertainties. In this manner we find the average positional accuracy as well as the isotropic and anisotropic positional accuracy associated with each atom in a crystal structure determined by NMR crystallography. The approach is demonstrated on the crystal structures of cocaine, flutamide, flufenamic acid, the K salt of penicillin G, and form 4 of the drug 4-[4-(2-adamantylcarbamoyl)-5-tert-butylpyrazol-1-yl]benzoic acid (AZD8329)...
February 8, 2017: Journal of the American Chemical Society
Soad K Salama, Magda F Mohamed, Ahmed F Darweesh, Ahmed H M Elwahy, Ismail A Abdelhamid
An efficient route for the synthesis of novel bis(1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile) derivatives is reported. The synthetic pathway involves one pot, synthesis of bis-aldehydes, malononitrile, and pyrazolone in the presence of pyridine. The anticancer activity of the synthesized products against MCF7, HEPG2, and A549 cell lines was assessed. Docking studies were performed and indicated the best binding mode compared to the standard ligand sorafenib.
January 21, 2017: Bioorganic Chemistry
Eva Řezníčková, Lukáš Tenora, Pavlína Pospíšilová, Juraj Galeta, Radek Jorda, Karel Berka, Pavel Majer, Milan Potáček, Vladimír Kryštof
A series of 2,3,4-substituted 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoles (DPPs) was synthesized and evaluated for their ALK5 inhibition activity. The most potent compounds displayed submicromolar IC50 values for ALK5. Preliminary profiling of one of the most active compounds in a panel of 50 protein kinases revealed its selectivity for ALK5. In cells, the compounds caused dose-dependent dephosphorylation of SMAD2, a well-established substrate of ALK5. In addition, the compounds blocked translocation of SMAD2/3 to nuclei of cells stimulated with TGFβ and the protein remained predominantly in cytoplasm, further confirming their molecular target...
January 12, 2017: European Journal of Medicinal Chemistry
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