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M Kvasnica, J Oklestkova, V Bazgier, L Rárová, P Korinkova, J Mikulík, M Budesinsky, T Béres, K Berka, Q Lu, E Russinova, M Strnad
We have prepared and studied a series of new brassinosteroid derivatives with a p-substituted phenyl group in the side chain. To obtain the best comparison between molecular docking and biological activities both types of brassinosteroids were synthesized; 6-ketones, 10 examples, and B-lactones, 8 examples. The phenyl group was introduced into the steroid skeleton by Horner-Wadsworth-Emmons. The docking studies were carried out using AutoDock Vina 1.05. Plant biological activities were established using different brassinosteroid bioassays in comparison with natural brassinosteroids...
September 21, 2016: Organic & Biomolecular Chemistry
Thomas Dresselhaus, Steffen Eusterwiemann, David R Matuschek, Constantin G Daniliuc, Oliver Janka, Rainer Pöttgen, Armido Studer, Johannes Neugebauer
In all but the simplest crystal structures, the identification of all relevant interactions between magnetic sites as well as the setup of magnetic model spaces, which are necessary for modeling macroscopic magnetism, are tedious and error-prone tasks. Here, we present a procedure to generate magnetic susceptibility versus temperature curves using only a crystal structure as input. The procedure, which is based on the first-principles bottom-up approach [Deumal et al., J. Phys. Chem. A, 2002, 106, 1299], is designed in a way to require as little user interference as possible...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
Heidy Herrera, Rodrigo Carvajal, Andrés F Olea, Luis Espinoza
An improved synthesis route for obtaining known brassinosteroid analogues, i.e., methyl 2α,3α-dihydroxy-6-oxo-5α-cholan-24-oate (11), methyl 3α-hydroxy-6-oxo-7-oxa-5α-cholan-24-oate (15) and methyl 3α-hydroxy-6-oxa-7-oxo-5α-cholan-24-oate (16), from hyodeoxycholic acid (4) maintaining the native side chain is described. In the alternative procedure, the di-oxidized product 6, obtained in the oxidation of methyl hyodeoxycholate 5, was converted almost quantitatively into the target monoketone 7 by stereoselective reduction with NaBH₄, increasing the overall yield of this synthetic route to 96...
2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Mingqiang Huang, Jiahui Zhang, Shunyou Cai, Yingmin Liao, Weixiong Zhao, Changjin Hu, Xuejun Gu, Li Fang, Weijun Zhang
Aging of secondary organic aerosol (SOA) particles formed from OH- initiated oxidation of ethylbenzene in the presence of high mass (100-300μg/m(3)) concentrations of (NH4)2SO4 seed aerosol was investigated in a home-made smog chamber in this study. The chemical composition of aged ethylbenzene SOA particles was measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) coupled with a Fuzzy C-Means (FCM) clustering algorithm. Experimental results showed that nitrophenol, ethyl-nitrophenol, 2,4-dinitrophenol, methyl glyoxylic acid, 5-ethyl-6-oxo-2,4-hexadienoic acid, 2-ethyl-2,4-hexadiendioic acid, 2,3-dihydroxy-5-ethyl-6-oxo-4-hexenoic acid, 1H-imidazole, hydrated N-glyoxal substituted 1H-imidazole, hydrated glyoxal dimer substituted imidazole, 1H-imidazole-2-carbaldehyde, N-glyoxal substituted hydrated 1H-imidazole-2-carbaldehyde and high-molecular-weight (HMW) components were the predominant products in the aged particles...
September 2016: Journal of Environmental Sciences (China)
Fuqin Fan, Zhixiang He, Lu-Lu Kong, Qinghua Chen, Quan Yuan, Shihao Zhang, Jinjin Ye, Hao Liu, Xiufeng Sun, Jing Geng, Lunzhi Yuan, Lixin Hong, Chen Xiao, Weiji Zhang, Xihuan Sun, Yunzhan Li, Ping Wang, Lihong Huang, Xinrui Wu, Zhiliang Ji, Qiao Wu, Ning-Shao Xia, Nathanael S Gray, Lanfen Chen, Cai-Hong Yun, Xianming Deng, Dawang Zhou
Tissue repair and regenerative medicine address the important medical needs to replace damaged tissue with functional tissue. Most regenerative medicine strategies have focused on delivering biomaterials and cells, yet there is the untapped potential for drug-induced regeneration with good specificity and safety profiles. The Hippo pathway is a key regulator of organ size and regeneration by inhibiting cell proliferation and promoting apoptosis. Kinases MST1 and MST2 (MST1/2), the mammalian Hippo orthologs, are central components of this pathway and are, therefore, strong target candidates for pharmacologically induced tissue regeneration...
August 17, 2016: Science Translational Medicine
L J Goad, M A Breen, N B Rendell, M E Rose, J N Duncan, A P Wade
A simple method is described for the preparation of [6,7,7(-2)H3] sterols and steroids. The synthesis starts with a Δ(5)-sterol or steroid and involves preparation of the 6-oxo-3α,5α-cyclosteroid, base exchange in the presence of deuterium oxide to introduce two deuteriums at the C-7 position and sodium borodeuteride reduction of the 6-oxo group to introduce the third deuterium atom at C-6. Rearrangement of the [6,7,7(-2)H3]6α-hydroxy-3α,5α-cyclosteroid then gives the desired [6,7,7(-2)H3]-Δ(5) sterol or steroid...
December 1982: Lipids
Vladimir A Kostin, Vladimir A Zolottsev, Alexey V Kuzikov, Rami A Masamrekh, Victoria V Shumyantseva, Alexander V Veselovsky, Sergey V Stulov, Roman A Novikov, Vladimir P Timofeev, Alexander Y Misharin
Five 4,5-dihydro-1,3-oxazole derivatives of [17(20)E]-21-norpregnene, comprising 3β-hydroxy-5-ene (1), 3,6-dioxo-4-ene (2), 3-oxo-4-ene (3), 3α,5α-cyclo-6-oxo (4), 3β-hydroxy-6-oxo (5) fragments were synthesized. Synthesis was conducted with improved procedure, based on reaction of suitably protected [17(20)E]-pregnen-21-oic acids with ethanolamine in presence of triphenyl phosphine, carbon tetrachloride, and triethyl amine. Potency of the compounds 1-5 to inhibit 17α-hydroxylase/17,20-lyase (CYP17A1) activity was studied by highly sensitive electrochemical method, using the enzyme immobilization technique...
November 2016: Steroids
Jason E Ham, Joel C Harrison, Stephen R Jackson, J R Wells
The reaction products from limonene ozonolysis were investigated using the new carbonyl derivatization agent, O-tert-butylhydroxylamine hydrochloride (TBOX). With ozone (O3) as the limiting reagent, five carbonyl compounds were detected. The yields of the carbonyl compounds are discussed with and without the presence of a hydroxyl radical (OH•) scavenger, giving insight into the influence secondary OH radicals have on limonene ozonolysis products. The observed reaction product yields for limonaketone (LimaKet), 7-hydroxyl-6-oxo-3-(prop-1-en-2-yl)heptanal (7H6O), and 2-acetyl-5-oxohexanal (2A5O) were unchanged suggesting OH• generated by the limonene + O3 reaction does not contribute to their formation...
May 2016: Atmospheric Environment
Daniela Vullo, Claudiu T Supuran, Andrea Scozzafava, Giuseppina De Simone, Simona Maria Monti, Vincenzo Alterio, Fabrizio Carta
Herein we report an in vitro kinetic evaluation against the most relevant human carbonic anhydrase (hCA, EC isoforms (I, II, IX and XII) of a small series of lactate dehydrogenase (LDH, EC inhibitors. All compounds contain a primary sulfonamide zinc-binding group (ZBG) substituted with the 2-thio-6-oxo-1,6-dihydropyrimidine scaffold. By means of X-ray crystallographic experiments we explored the ligand-enzyme binding modes, thus highlighting the contribution of the 2-thio-6-oxo-1,6-dihydropyrimidine moiety to the stabilization of the complex...
August 15, 2016: Bioorganic & Medicinal Chemistry
Christine Knies, Katharina Hammerbacher, Gabriel A Bonaterra, Ralf Kinscherf, Helmut Rosemeyer
We report on the synthesis of two series of canonical purine ß-d-ribonucleoside nucleolipids derived from inosine and adenosine, which have been characterized by elemental analyses, electrospray ionization mass spectrometry (ESI MS) as well as by (1)H and (13)C NMR, and pH-dependent UV/Vis spectroscopy. A selection of the novel nucleolipids with different lipophilic moieties were first tested on their cytotoxic effect toward human macrophages. Compounds without a significant inhibitory effect on the viability of the macrophages were tested on their cytostatic/cytotoxic effect toward human astrocytoma/oligodendroglioma GOS-3 cells as well as against the rat malignant neuroectodermal BT4Ca cell line...
April 2016: ChemistryOpen
M John Plater, William T A Harrison
In the cation of the title hydrated mol-ecular salt, C6H7N2O2 (+)·Cl(-)·H2O, the six-membered ring shows unequal bond lengths consistent with delocalization of electrons over two separate 6π systems with single bonds between them. In the crystal, the components are linked by N-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen bonds, generating double layers propagating in (100).
May 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
Aleksandra Rajnisz, Adam Guśpiel, Magdalena Postek, Joanna Ziemska, Anna Laskowska, Daniel Rabczenko, Jolanta Solecka
The nutritional requirements and environmental conditions for a submerged culture of Streptomyces sp. 8812 were determined. Batch and fed-batch Streptomyces sp. 8812 fermentations were conducted to obtain high activity of secondary metabolites. In the study several factors were examined for their influence on the biosynthesis of the active metabolites-7-hydroxy-6-oxo-2,3,4,6-tetrahydroisoquinoline-3-carboxy acid (C10H9NO4) and N-acetyl-3,4-dihydroxy-L-phenylalanine (C11H13NO5): changes in medium composition, pH of production medium, various growth phases of seed culture, amino acid supplementation and addition of anion exchange resin to the submerged culture...
2016: Polish Journal of Microbiology
I Marszałek, A Krężel, W Goch, I Zhukov, I Paczkowska, W Bal
2-[2-[2-[2-[bis(carboxylatomethyl)amino]-5-methoxyphenoxy]ethoxy]-4-(2,7-difluoro-3-oxido-6-oxo-4a,9a-dihydroxanthen-9-yl)anilino]acetate (FluoZin-3) is used very broadly in life sciences as intra- and extracellular Zn(II) sensor selective for Zn(II) over Co(II), Ca(II) and Mg(II) ions at their physiological concentrations. It has been used for determination of relative and absolute levels of exchangeable Zn(II) in cells and extracellular fluids. Despite its popularity, the knowledge of its acid/base and Zn(II) coordination abilities and of its spectroscopic properties remained very limited...
August 2016: Journal of Inorganic Biochemistry
Saloni B Patel, Bhumika D Patel, Christophe Pannecouque, Hardik G Bhatt
In order to design novel anti-HIV agents, pharmacophore modelling, virtual screening, 3D-QSAR and molecular docking studies were performed. Pharmacophore model was generated using 17 structurally diverse molecules using DISCOtech followed by refinement with GASP module of Sybyl X. The best model containing four features; two donor sites, one acceptor atom and one hydrophobic region; was used as a query for virtual screening in NCI database and 6 compounds with Qfit value ≥98 were retrieved. The quinoxaline ring which is the bio-isostere of pteridine ring, retrieved as a hit in virtual screening, was selected as a core moiety...
July 19, 2016: European Journal of Medicinal Chemistry
Nadezhda Markova, Ljupco Pejov, Nina Stoyanova, Venelin Enchev
To provide an in-depth insight into the molecular basis of spontaneous tautomerism in DNA and RNA base pairs, a hybrid Monte Carlo (MC) - quantum chemical (QC) methodology is implemented to map two-dimensional potential energy surfaces along the reaction coordinates of solvent-assisted proton transfer processes in guanosine and its analogue acyclovir in aqueous solution. The solvent effects were simulated by explicit inclusion of water molecules which model the relevant part of the first hydration shell around the solute...
April 19, 2016: Journal of Biomolecular Structure & Dynamics
Steffen Eusterwiemann, David Matuschek, Linda Stegemann, Sina Klabunde, Carsten C Doerenkamp, Constantin G Daniliuc, Nikos L Doltsinis, Cristian A Strassert, Hellmut Eckert, Armido Studer
Methods for the detection of reactive intermediates such as transient radicals are important in organic chemistry, polymer chemistry, biology or medicine. Along these lines we recently reported that 1,5-diphenyl-6-oxo verdazyl radicals can be used as fluorescent spin sensors. In situ generated C-centered radicals are efficiently trapped by the verdazyls, which in turn undergo transformation from a paramagnetic non-fluorescent state to a diamagnetic fluorescent state. Whereas the N-phenyl substituent in the spin probes is of high importance for obtaining profluorescent behavior, the effect of the C(3)-substituent has not been investigated to date...
2016: Chimia
Matthäus Getlik, David Smil, Carlos Zepeda-Velázquez, Yuri Bolshan, Gennady Poda, Hong Wu, Aiping Dong, Ekaterina Kuznetsova, Richard Marcellus, Guillermo Senisterra, Ludmila Dombrovski, Taraneh Hajian, Taira Kiyota, Matthieu Schapira, Cheryl H Arrowsmith, Peter J Brown, Masoud Vedadi, Rima Al-Awar
WD repeat-containing protein 5 (WDR5) is an important component of the multiprotein complex essential for activating mixed-lineage leukemia 1 (MLL1). Rearrangement of the MLL1 gene is associated with onset and progression of acute myeloid and lymphoblastic leukemias, and targeting the WDR5-MLL1 interaction may result in new cancer therapeutics. Our previous work showed that binding of small molecule ligands to WDR5 can modulate its interaction with MLL1, suppressing MLL1 methyltransferase activity. Initial structure-activity relationship studies identified N-(2-(4-methylpiperazin-1-yl)-5-substituted-phenyl) benzamides as potent and selective antagonists of this protein-protein interaction...
March 24, 2016: Journal of Medicinal Chemistry
Soňa Jantová, Nataša Mrvová, Roman Hudec, Ján Sedlák, Miroslav Pánik, Viktor Milata
7- ethyl 9-ethyl-6-oxo-6,9-dihydro[1,2,5]selenadiazolo [3,4-h]quinoline-7-carboxylate (E2h) is a new synthetically prepared quinolone derivative, which in our primary study showed cytotoxic effects towards tumor cells. The aim of the present study was to examine the antiproliferative and apoptosis inducing activities of E2h towards human cervical cancer cell line HeLa with/without the presence of UVA irradiation. Further, the molecular mechanism involved in E2h-induced apoptosis in HeLa cells was investigated...
June 2016: Toxicology in Vitro: An International Journal Published in Association with BIBRA
Rubén Pérez-Aguirre, Sonia Pérez-Yáñez, Garikoitz Beobide, Oscar Castillo, Juan Manuel Gutiérrez-Zorrilla, Antonio Luque
In a new polymorph of the title salt, [Ni(H2O)6](C6H4NO3)2, the metal atom of the cationic complex lies on a symmetry centre and is coordinated by six water mol-ecules to provide a quite regular octa-hedral coordination environment. These cations inter-act with 6-oxo-1,6-di-hydro-pyridine-3-carboxyl-ate anions through electrostatic inter-actions and by means of O-H⋯O and N-H⋯O hydrogen bonds involving the carboxyl-ate, keto and protonated imine groups of the anion, and the coordinating water mol-ecules from the cationic complex entity to generate a supra-molecular three-dimensional architecture...
December 1, 2015: Acta Crystallographica. Section E, Crystallographic Communications
Bin-Bin Feng, Lian Lu, Chao Li, Xiang-Shan Wang
An iodine-catalyzed reaction of 2-aminobenzamides and mucobromic acid was described and utilized to synthesize a variety of 6-oxo-5,6-dihydrodibenzo[b,h][1,6]naphthyridine-11-carboxamide derivatives in refluxing THF. As the two bromine atoms in mucobromic acid were found missing in the dibenzonaphthyridine products, a domino-type reaction mechanism involving a double elimination of hydrogen bromide was proposed.
March 7, 2016: Organic & Biomolecular Chemistry
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