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Jiping Ma, Zhidan Yao, Liwei Hou, Wenhui Lu, Qipeng Yang, Jinhua Li, Lingxin Chen
Magnetic metal-organic frameworks (MOFs, [MIL-101]) were prepared and used as magnetic solid-phase extraction (MSPE) adsorbents for preconcentration of four kinds of pyrazole/pyrrole pesticides (flusilazole, fipronil, chlorfenapyr, and fenpyroximate) in environmental water samples, followed by high-performance liquid chromatography-diode-array detector (HPLC-DAD) determination. Several variables affecting MSPE efficiency were systematically investigated, including amount of MIL-101, extraction time, sample pH, salt concentration, type of desorption solvent and desorption number of times...
December 1, 2016: Talanta
Atsushi Umehara, Hirofumi Ueda, Hidetoshi Tokuyama
A novel condensation reaction of carboxylic acids with various non-nucleophilic N-heterocycles and anilides was developed. The reaction proceeds in the presence of di-tert-butyl dicarbonate (Boc2O), catalytic 4-(dimethylamino)pyridine (DMAP), and 2,6-lutidine and is applicable to the acylation of a wide range of non-nucleophilic nitrogen compounds, including indoles, pyrroles, pyrazole, carbazole, lactams, oxazolidinones, and anilides with high functional group compatibility. The scope of indoles, carboxylic acids, and anilides was also studied...
October 21, 2016: Journal of Organic Chemistry
Sohag Biswas, Bhabani S Mallik
We present the characteristic proton transfer process from water to the pyrazole anion, infrared signatures of hydroxyl groups and the free energy profile of the process in aqueous solution combining first principles simulations, wavelet analysis and metadynamics. Our results show that the presence of minimum three water molecules in the gas phase cluster with a particular arrangement is sufficient to facilitate the proton transfer process from water to the anion. The overall reaction is very rapid in aqueous solution, and the free energy barrier for this process is found to be 4...
October 21, 2016: Physical Chemistry Chemical Physics: PCCP
Nidhi Singh, Priyanka Shah, Hemlata Dwivedi, Shikha Mishra, Renu Tripathi, Amogh A Sahasrabuddhe, Mohammad Imran Siddiqi
N-Myristoyltransferase (NMT) catalyzes the transfer of myristate to the amino-terminal glycine of a subset of proteins, a co-translational modification involved in trafficking substrate proteins to membrane locations, stabilization and protein-protein interactions. It is a studied and validated pre-clinical drug target for fungal and parasitic infections. In the present study, a machine learning approach, docking studies and CoMFA analysis have been integrated with the objective of translation of knowledge into a pipelined workflow towards the identification of putative hits through the screening of large compound libraries...
October 21, 2016: Molecular BioSystems
Ping Yin, Lauren A Mitchell, Damon A Parrish, Jean'ne M Shreeve
N-Nitramino/N-oxyl functionalization strategies were employed to investigate structure-property relationships of energetic materials. Based on single-crystal diffraction data, π-π stacking of pyrazole backbones can be tailored effectively by energetic functionalities, thereby resulting in diversified energetic compounds. Among them, hydroxylammonium 4-amino-3,5-dinitro-1H-pyrazol-1-olate and dipotassium N,N'-(3,5-dinitro-1H-pyrazol-1,4-diyl)dinitramidate, with unique face-to-face π-π stacking, can be potentially used as a high-performance explosive and an energetic oxidizer, respectively...
October 20, 2016: Angewandte Chemie
Baolei Tang, Houyu Zhang, Kaiqi Ye, Hongyu Zhang, Yue Wang
3(5)-Phenyl-1H-pyrazoles are employed in this study to develop highly efficient organic crystalline solids with deep-blue ESIPT fluorescence as well as provide novel experimental insight into the mechanism of ESIPT fluorescence and generate an intriguing fluorescence "ON/OFF" switching.
October 20, 2016: Chemical Communications: Chem Comm
Preeti Rawat, Lokesh M Saroj, Anil Kumar, Tryambak D Singh, S K Tewari, Mahesh Pal
BACKGROUND: The plant Launaea procumbens belongs to the family Asteraceae and traditionally used in the treatment rheumatism, kidney, liver dysfunctions and eye diseases. In the present study Phytochemical analysis and fractions of methanolic extract of L. procumbens leaves were tested in vitro for their cytotoxicity. OBJECTIVES: Phytochemical analysis and cytotoxic activity of methanolic extract and fractions of Launaea procumbens against four cancer cell lines K562, HeLa, MIA-Pa-Ca-2 and MCF-2 by SRB assay...
July 2016: Pharmacognosy Magazine
Gretchen Bain, Kristen E Shannon, Fei Huang, Janice Darlington, Lance Goulet, Patricia Prodanovich, Gina L Ma, Angelina M Santini, Adam J Stein, Dave Lonergan, Christopher D King, Imelda Calderon, Andiliy Lai, John H Hutchinson, Jilly F Evans
Autotaxin (ATX) is a secreted glycoprotein that converts lysophosphatidylcholine (LPC) to the bioactive phospholipid lysophosphatidic acid (LPA) and is the major enzyme generating circulating LPA. Inhibition of LPA signaling has profound anti-fibrotic effects in multiple organ systems including the lung, kidney, skin and peritoneum. However, other LPA-generating pathways exist and the role of ATX in localized tissue LPA production and fibrosis remains unclear and controversial. In this study, we describe the preclinical pharmacological, pharmacokinetic and pharmacodynamic properties of a novel small-molecule ATX inhibitor [3-((6-chloro-2-cyclopropyl-1-(1-ethyl-1H-pyrazol-4-yl)-7-fluoro-1H-indol-3-yl) thio)-2-fluorobenzoic acid sodium salt] (PAT-505)...
October 17, 2016: Journal of Pharmacology and Experimental Therapeutics
Charlie E Kivi, Datong Song
A new metal-organic framework (1) constructed from 4-(4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl)pyridine (HL) and CuBr shows potential as a luminescent sensor for volatile organic compounds.
October 17, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Eunjin Kwon, Jineun Kim, Hyunjin Park, Tae Ho Kim
The title compound, C13H16N10O5S (systematic name: 1-(4,6-di-meth-oxypyrimidin-2-yl)-3-{[1-methyl-4-(2-methyl-2H-tetra-zol-5-yl)pyrazol-5-yl]sulfonyl}urea), is a second triclinic polymorph of this crystal [for the other, see: Jeon et al., (2015 ▸). Acta Cryst. E71, o470-o471]. There are two mol-ecules, A and B, in the asymmetric unit; the dihedral angles between the pyrazole ring and the tetra-zole and di-meth-oxy-pyrimidine ring planes are 72.84 (10) and 37.24 (14)°, respectively (mol-ecule A) and 84...
October 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
Can Zhao, Xiao-Zong Li, Hong-Lan Kang, Yi-Hang Wen
The title compound, [Co(C11H8O5)(C8H7N3)] n , which is based on (E)-3-[3-(carb-oxy-meth-oxy)phen-yl]acrylic acid (H2L) and 3-(pyridin-4-yl)pyrazole (pp) ligands, has been synthesized under solvothermal conditions. The dihedral angle between pyrazole and pyridine rings in the pp ligands is 23.1 (2)°. In the crystal, helical chains formed by pp and L ligands connected to the Co(II) atom propagate parallel to the c axis. Co(II) atoms of adjacent chains are bridged by the acrylic acid groups of L ligands into corrugated polymeric sheets in the ac plane...
October 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
Özden Özel Güven, Gökhan Türk, Philip D F Adler, Simon J Coles, Tuncer Hökelek
In the title compound, C20H16Cl2N2O2, the indazole ring system is approximately planar [maximum deviation = 0.033 (1) Å], its mean plane is oriented at dihedral angles of 25.04 (4) and 5.10 (4)° to the furan and benzene rings, respectively. In the crystal, pairs of C-Hind⋯Obo (ind = indazole and bo = benz-yloxy) hydrogen bonds link the mol-ecules into centrosymmetric dimers with graph-set motif R2(2)(12). Weak C-H⋯π inter-actions is also observed. Aromatic π-π stacking between the benzene and the pyrazole rings from neighbouring mol-ecules [centroid-centroid distance = 3...
October 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
Raquib Alam, Divya Wahi, Raja Singh, Devapriya Sinha, Vibha Tandon, Abhinav Grover, Rahisuddin
In an attempt to find potential anticancer agents, a series of novel ethyl 4-(3-(aryl)-1-phenyl-1H-pyrazol-4-yl)-2-oxo-6-(pyridin-3-yl)cyclohex-3-enecarboxylates 5a-i and 5-(3-(4-fluorophenyl)-1-phenyl-1H-pyrazol-4-yl)-3-(pyridin-3-yl)-4,5-dihydropyrazole-1-carbothioamides 6a-i were designed, synthesized and evaluated for their topoisomerase IIα inhibitory activity and in vitro cytotoxicity against a panel of cancerous cell lines (MCF-7, NCI-H460, HeLa) and a normal cell line (HEK-293T). Molecular docking studies of all the synthesized compounds into the binding site of topoisomerase IIα protein (PDB ID: 1ZXM) were performed to gain a comprehensive understanding into plausible binding modes...
October 5, 2016: Bioorganic Chemistry
Yaseen A M M Elshaier, Assem Barakat, Bander M Al-Qahtany, Abdullah Mohammed Al-Majid, Mohamed H Al-Agamy
A one-pot reaction was described that results in various pyrazole-thiobarbituric acid derivatives as new pharmacophore agents. These new heterocycles were synthesized in high yields with a broad substrate scope under mild reaction conditions in water mediated by NHEt₂. The molecular structures of the synthesized compounds were assigned based on different spectroscopic techniques. The new compounds were evaluated for their antibacterial and antifungal activity. Compounds 4h and 4l were the most active compounds against C...
October 9, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Shaukat Ali M Shaikh, Atanu Barik, Beena G Singh, Ramani V Madukuri, Neduri V Balaji, Gottumukkal V Subbaraju, Devidas B Naik, K Indira Priyadarsini
Hispolon (HS), a natural polyphenol found in medicinal mushrooms, and its isoxazole (HI) and pyrazole (HP) derivatives have been examined for free radical reactions and in vitro antioxidant activity. Reaction of these compounds with one-electron oxidant, azide radicals (N3(•)) and trichloromethyl peroxyl radicals (CCl3O2(•)), model peroxyl radicals, studied by nanosecond pulse radiolysis technique, indicated formation of phenoxyl radicals absorbing at 420 nm with half life of few hundred microseconds (µs)...
October 13, 2016: Free Radical Research
Nedyalka Radeva, Johannes Schiebel, Xiaojie Wang, Stefan G Krimmer, Kan Fu, Martin Stieler, Frederik R Ehrmann, Alexander Metz, Thomas Rickmeyer, Michael Betz, Johan Winquist, Ah Young Park, Franziska U Huschmann, Manfred S Weiss, Uwe Mueller, Andreas Heine, Gerhard Klebe
Crystallography is frequently used as follow-up method to validate hits identified by biophysical screening cascades. The capacity of crystallography to directly screen fragment libraries is often underestimated, due to its supposed low-throughput and need for high-quality crystals. We applied crystallographic fragment screening to map the protein-binding site of the aspartic protease endothiapepsin by individual soaking experiments. Here, we report on 41 fragments binding to the catalytic dyad and adjacent specificity pockets...
October 11, 2016: Journal of Medicinal Chemistry
Zi-Li Ren, Jing Zhang, Hai-Dong Li, Ming-Jie Chu, Li-Song Zhang, Xiao-Kang Yao, Yong Xia, Xian-Hai Lv, Hai-Qun Cao
Acetylcholinesterase (AChE) is a key enzyme which present in the central nervous system of living organisms. Organophosphorus pesticides (OPs) that serve as insecticides are AChE inhibitors which have been used widely in agriculture. A series of novel OPs containing pyrazole moiety have been designed and synthesized. The biological evaluation indicated compound 4e appeared 81% larvicidal activity against P. xylostella at the concentration of 0.1 mg/L and the inhibition of AChE by compound 4e was distinctly enhanced with the increasing doses...
October 1, 2016: Chemical & Pharmaceutical Bulletin
Nataliya S Goulioukina, Nikolay N Makukhin, Egor D Shinkarev, Yuri K Grishin, Vitaly A Roznyatovsky, Irina P Beletskaya
5-Aryl-substituted pyrazol-3-ylphosphonates have been conveniently synthesized by 1,3-dipolar cycloaddition of 1-formamidovinylphosphonates and aryldiazomethanes under K2CO3/MeOH conditions at room temperature. These pyrazoles are formed in one pot via spontaneous elimination of formamide. Basic conditions prevent competitive formation of cyclopropylphosphonates. 3-Aryl substituted pyrazol-5-carboxylates can be synthesized by the same methodology from 1-arylvinylphosphonates and ethyl diazoacetate, although a stronger base NaH is necessary to ensure the success of the aromatization stage with the elimination of the diethoxylphosphoryl moiety...
October 4, 2016: Organic & Biomolecular Chemistry
Małgorzata J Gajewska, Alina Bieńko, Radovan Herchel, Matti Haukka, Maria Jerzykiewicz, Andrzej Ożarowski, Krzysztof Drabent, Chen-Hsiung Hung
The synthesis, structural aspects, magnetic interpretation and theoretical rationalizations for a new member of the ferric wheel family, a decanuclear iron(iii) complex with the formula [Fe10(bdtbpza)10(μ2-OCH3)20] (1), featuring the N,N,O tridentate bis(3,5-di-tert-butylpyrazol-1-yl)acetate ligand, are reported. The influence of the steric effect on both the core geometry and coordination mode is observed. Temperature dependent (2.0-300 K range) magnetic susceptibility studies carried out on complexes 1 established unequivocally antiferromagnetic (AF) interactions between high-spin iron(iii) centers (S = 5/2), leading to a ground state S = 0...
September 27, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Milan M Milutinović, Jovana V Bogojeski, Olivera Klisurić, Andreas Scheurer, Sofi K C Elmroth, Živadin D Bugarčić
A novel rhodium(iii) complex [Rh(III)(H2L(tBu))Cl3] (1) (H2L(tBu) = 2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine) containing a pincer type, tridentate nitrogen-donor chelate system was synthesized. Single crystal X-ray structure analysis revealed that 1 crystallizes in the orthorhombic space group Pbcn with a = 20.7982(6), b = 10.8952(4), c = 10.9832(4) Å, V = 2488.80(15) Å(3), and eight molecules in the unit cell. The rhodium center in the complex [Rh(III)(H2L(tBu))Cl3] (1) is coordinated in a slightly distorted octahedral geometry by the tridentate N,N,N-donor and three chloro ligands, adopting a mer arrangement with an essentially planar ligand skeleton...
October 4, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
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