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https://www.readbyqxmd.com/read/27923180/insight-into-the-structure-and-stability-of-tc-and-re-dmsa-complexes-a-computational-study
#1
Daniel Hernández-Valdés, Alejandro Blanco-González, Ariel García-Fleitas, Zalua Rodríguez-Riera, Giuseppe Meola, Roger Alberto, Ulises Jáuregui-Haza
Meso-2,3-dimercaptosuccinic acid (DMSA) is used in nuclear medicine as ligand for preparation of diagnostic and therapy radiopharmaceuticals. DMSA has been the subject of numerous investigations during the past three decades and new and significant information of the chemistry and pharmacology of DMSA complexes have emerged. In comparison to other ligands, the structure of some DMSA complexes is unclear up today. The structures and applications of DMSA complexes are strictly dependent on the chemical conditions of their preparation, especially pH and components ratio...
November 27, 2016: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/27923110/impact-of-oligonucleotide-structure-chemistry-and-delivery-method-on-in-vitro-cytotoxicity
#2
Maja M Janas, Yongfeng Jiang, Mark K Schlegel, Scott Waldron, Satya Kuchimanchi, Scott A Barros
Single-stranded (ss) 2'-fluoro (2'-F)-modified oligonucleotides (ONs) with a full phosphorothioate (PS) backbone have been reported to be cytotoxic and cause DNA double-strand breaks (DSBs) when transfected into HeLa cells. However, the molecular determinants of these effects have not been fully explored. In this study, we investigated the impact of ON structure, chemistry, delivery method, and cell type on in vitro cytotoxicity and DSBs. We found that ss PS-ONs were more cytotoxic than double-stranded (ds) PS-ONs, irrespective of the 2'-ribose chemistry, inclusive of the 2'-F modification...
December 6, 2016: Nucleic Acid Therapeutics
https://www.readbyqxmd.com/read/27922205/one-pot-preparation-of-dimethyl-isosorbide-from-d-sorbitol-via-dimethyl-carbonate-chemistry
#3
Fabio Arico', Pietro Tundo, Alexander Aldoshin
Direct synthesis of dimethyl isosorbide (DMI) from D-sorbitol via dimethyl carbonate (DMC) chemistry is herein firstly reported. High yield of DMI was achieved using nitrogen superbase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as catalyst and performing the reaction in a stainless steel autoclave by increasing the temperature from 90°C to 200 °C. In this procedure DMC features its full capacity, acting in the different steps of the process as carboxymethylating, leaving group (cyclization) and methylating agent; DMC is also employed as the reaction media...
December 6, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27921226/the-relationship-between-aerosol-particles-chemical-composition-and-optical-properties-to-identify-the-biomass-burning-contribution-to-fine-particles-concentration-a-case-study-for-s%C3%A3-o-paulo-city-brazil
#4
Regina Maura de Miranda, Fabio Lopes, Nilton Évora do Rosário, Marcia Akemi Yamasoe, Eduardo Landulfo, Maria de Fatima Andrade
The air quality in the Metropolitan Area of São Paulo (MASP) is primarily determined by the local pollution source contribution, mainly the vehicular fleet, but there is a concern about the role of remote sources to the fine mode particles (PM2.5) concentration and composition. One of the most important remote sources of atmospheric aerosol is the biomass burning emissions from São Paulo state's inland and from the central and north portions of Brazil. This study presents a synergy of different measurements of atmospheric aerosol chemistry and optical properties in the MASP in order to show how they can be used as a tool to identify particles from local and remote sources...
December 2016: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/27920947/the-daniel-k-inouye-college-of-pharmacy-scripts-poha-berry-physalis-peruviana-with-potential-anti-inflammatory-and-cancer-prevention-activities
#5
Leng Chee Chang, Mayuramas Sang-Ngern, John M Pezzuto, Carolyn Ma
The Daniel K. Inouye College of Pharmacy, during a historic event in Spring 2016, graduated the first two students in the Pacific region to earn a PhD in pharmaceutical sciences at the University of Hawai'i at Hilo. The college offers PhD programs in these five disciplines: Cancer Biology, Medicinal Chemistry, Pharmaceutics, Pharmacognosy, and Pharmacology. One of the Pharmacognosy dissertations focused on plant-derived natural products with potential anti-inflammatory and cancer chemopreventive activities...
November 2016: Hawai'i Journal of Medicine & Public Health: a Journal of Asia Pacific Medicine & Public Health
https://www.readbyqxmd.com/read/27920905/an-unprecedented-binuclear-cadmium-di-thio-carbamate-adduct-bis-%C3%AE-2-n-2-hydroxy-eth-yl-n-iso-propyl-carbamodi-thio-ato-%C3%AE%C2%BA-3-s-s-s-bis-n-2-hydroxy-eth-yl-n-iso-propyl-carbamodi-thio-ato-%C3%AE%C2%BA-2-s-s-3-1e-e-2-pyridin-3-yl-methyl-idene-hydrazin-1-yl-idene-meth-yl
#6
Hadi D Arman, Pavel Poplaukhin, Edward R T Tiekink
The asymmetric unit in the title binuclear compound, [Cd(C6H12NOS2)2(C12H10N4)]2·2H2O, comprises a Cd(II) atom, two di-thio-carbamate (dtc) anions, a monodentate 3-pyridine-aldazine ligand and a lattice water mol-ecule. The binuclear mol-ecule is constructed by the application of inversion symmetry. One dtc ligand simultaneously chelates one cadmium atom and bridges the centrosymmetric mate, while the other dtc ligand is chelating only. This leads to a centrosymmetric [Cd(dtc)2]2 core to which are appended two 3-pyridine-aldazine ligands...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920217/navigating-challenges-in-the-application-of-superresolution-microscopy
#7
REVIEW
Talley J Lambert, Jennifer C Waters
In 2014, the Nobel Prize in Chemistry was awarded to three scientists who have made groundbreaking contributions to the field of superresolution (SR) microscopy (SRM). The first commercial SR microscope came to market a decade earlier, and many other commercial options have followed. As commercialization has lowered the barrier to using SRM and the awarding of the Nobel Prize has drawn attention to these methods, biologists have begun adopting SRM to address a wide range of questions in many types of specimens...
December 5, 2016: Journal of Cell Biology
https://www.readbyqxmd.com/read/27919815/chemical-modification-of-functionalized-polyhydroxyalkanoates-via-click-chemistry-a-proof-of-concept
#8
Samuel Nkrumah-Agyeefi, Carmen Scholz
A novel approach to the post-biosynthetic chemical modification of bromo and alkyne functionalized poly(3-hydroxyalkanoates), (PHAs), via copper-catalyzed azide-alkyne cycloaddition (CuAAC) and strain promoted azide alkyne cycloaddition (SPAAC) is reported. Optimum conditions for the biosynthesis of the PHA copolymers, poly(3-hydroxynonanoate-co-3-hydroxy-11-bromoundecanoate) (PHNUBr) and poly(3-hydroxynonanoate-co-3-hydroxy-10-undecynoate) (PHNUD), using Pseudomonas oleovorans as cell factories were 20h of fermentation time and a total carbon substrate concentration of 40mM...
December 2, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27919559/effects-of-flow-regime-on-benthic-algae-and-macroinvertebrates-a-comparison-between-regulated-and-unregulated-rivers
#9
Susanne C Schneider, Zlatko Petrin
Natural fluctuations in flow are important for maintaining the ecological integrity of riverine ecosystems. However, the flow regime of many rivers has been modified. We assessed the impact of water chemistry, habitat and streamflow characteristics on macroinvertebrates and benthic algae, comparing 20 regulated with 20 unregulated sites. Flow regime, calculated from daily averaged discharge over the five years preceding sampling, was generally more stable at regulated sites, with higher relative discharges in winter, lower relative discharges in spring and smaller differences between upper and lower percentiles...
December 2, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27918627/exploring-dynamic-surface-processes-during-silicate-mineral-wollastonite-dissolution-with-liquid-cell-tem
#10
D N Leonard, R Hellmann
Most liquid cell transmission electron microscopy (LC TEM) studies focus on nanoparticles or nanowires, in large part because the preparation and study of materials in this size range is straightforward. By contrast, this is not true for samples in the micrometre size range, in large part because of the difficulties associated with sample preparation starting from a 'bulk' material. There are also many advantages inherent to the study of micrometre-sized samples compared to their nanometre-sized counterparts...
December 5, 2016: Journal of Microscopy
https://www.readbyqxmd.com/read/27918613/defining-the-radiation-chemistry-during-liquid-cell-electron-microscopy-to-enable-visualization-of-nanomaterial-growth-and-degradation-dynamics
#11
T J Woehl, P Abellan
We present a critical review of methods for defining the chemical environment during liquid cell electron microscopy investigation of electron beam induced nanomaterial growth and degradation. We draw from the radiation chemistry and liquid cell electron microscopy literature to present solution chemistry and electron beam-based methods for selecting the radiolysis products formed and their relative amount during electron irradiation of liquid media in a transmission electron microscope. We outline various methods for establishing net oxidizing or net reducing reaction environments and propose solvents with minimal overall production of radicals under the electron beam...
December 5, 2016: Journal of Microscopy
https://www.readbyqxmd.com/read/27918555/gene-expression-profiling-of-anti-ctla4-treated-metastatic-melanoma-in-patients-with-treatment-induced-autoimmunity
#12
Scott C Bresler, Le Min, Scott J Rodig, Andrew C Walls, Shuyun Xu, Songmei Geng, F Stephen Hodi, George F Murphy, Christine G Lian
Ipilimumab (IPI) is a monoclonal antibody that targets the inhibitory CTLA4 receptor of T cells, enhancing T-cell-driven antitumor responses. IPI therapy in metastatic melanoma results in significant improvement in disease-free and overall survival, although after initial responses disease progression generally ensues. Identification of specific responses in tissue where melanoma tumor cells are subjected to IPI-driven immune attack may reveal mechanisms of treatment efficacy or resistance, permitting refinement of targeted therapeutic approaches...
December 5, 2016: Laboratory Investigation; a Journal of Technical Methods and Pathology
https://www.readbyqxmd.com/read/27918545/warfarin-traps-human-vitamin-k-epoxide-reductase-in-an-intermediate-state-during-electron-transfer
#13
Guomin Shen, Weidong Cui, Hao Zhang, Fengbo Zhou, Wei Huang, Qian Liu, Yihu Yang, Shuang Li, Gregory R Bowman, J Evan Sadler, Michael L Gross, Weikai Li
Although warfarin is the most widely used anticoagulant worldwide, the mechanism by which warfarin inhibits its target, human vitamin K epoxide reductase (hVKOR), remains unclear. Here we show that warfarin blocks a dynamic electron-transfer process in hVKOR. A major fraction of cellular hVKOR is in an intermediate redox state containing a Cys51-Cys132 disulfide, a characteristic accommodated by a four-transmembrane-helix structure of hVKOR. Warfarin selectively inhibits this major cellular form of hVKOR, whereas disruption of the Cys51-Cys132 disulfide impairs warfarin binding and causes warfarin resistance...
December 5, 2016: Nature Structural & Molecular Biology
https://www.readbyqxmd.com/read/27918304/new-fluorous-ponytailed-4-2-2-2-trifluoroethoxy-methyl-pyridinium-halide-salts
#14
Norman Lu, Mani Alagesan, Chi Liang Ho, Rong Jyun Wei, Chih Chieh Kung, Jung Shan Chang, Yuh Sheng Wen, Ling Kang Liu
It is possible that fluorous compounds could be utilized as directing forces in crystal engineering for applications in materials chemistry or catalysis. Although numerous fluorous compounds have been used for various applications, their structures in the solid state remains a lively matter for debate. The reaction of 4-[(2,2,2-trifluoroethoxy)methyl]pyridine with HX (X = I or Cl) yielded new fluorous ponytailed pyridinium halide salts, namely 4-[(2,2,2-trifluoroethoxy)methyl]pyridinium iodide, C8H9F3NO(+)·I(-), (1), and 4-[(2,2,2-trifluoroethoxy)methyl]pyridinium chloride, C8H9F3NO(+)·Cl(-), (2), which were characterized by IR spectroscopy, multinuclei ((1)H, (13)C and (19)F) NMR spectroscopy and single-crystal X-ray diffraction...
December 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
https://www.readbyqxmd.com/read/27918300/three-polymorphs-of-an-inclusion-compound-of-2-2-disulfanediyl-dibenzoic-acid-and-trimethylamine
#15
Yunxia Yang, Lihua Li, Li Zhang, Wenjing Dong, Keying Ding
Polymorphism is the ability of a solid material to exist in more than one form or crystal structure and this is of interest in the fields of crystal engineering and solid-state chemistry. 2,2'-(Disulfanediyl)dibenzoic acid (also called 2,2'-dithiosalicylic acid, DTSA) is able to form different hydrogen bonds using its carboxyl groups. The central bridging S atoms allow the two terminal arene rings to rotate freely to generate various hydrogen-bonded linking modes. DTSA can act as a potential host molecule with suitable guest molecules to develop new inclusion compounds...
December 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
https://www.readbyqxmd.com/read/27918047/oxidations-of-chromene-annulated-chlorins
#16
Nisansala Hewage, Matthias Zeller, Christian Brückner
A chromene-annulated chlorin is a meso-pentafluorophenyl-2,3-dihydroxychlorin in which one of the hydroxy groups is linked to the ortho-position of a flanking meso-aryl group, thereby forming an annulated chromene moiety; the second hydroxy group is unprotected. This report illustrates the oxidation chemistry of the chromene-annulated chlorin under a number of different oxidation conditions. In some reactions, chromene annulation is retained and the non-protected alcohol is oxidized, generating chlorin-like chromophores carrying pyrroline β-carbons in oxidation states between those found in typical porphyrins and chlorins...
December 5, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27918022/a-systematic-study-of-25-mg-nmr-in-paramagnetic-transition-metal-oxides-applications-to-mg-ion-battery-materials
#17
Jeongjae Lee, Ieuan D Seymour, Andrew J Pell, Siân E Dutton, Clare P Grey
Rechargeable battery systems based on Mg-ion chemistries are generating significant interest as potential alternatives to Li-ion batteries. Despite the wealth of local structural information that could potentially be gained from Nuclear Magnetic Resonance (NMR) experiments of Mg-ion battery materials, systematic (25)Mg solid-state NMR studies have been scarce due to the low natural abundance, low gyromagnetic ratio, and significant quadrupole moment of (25)Mg (I = 5/2). This work reports a combined experimental (25)Mg NMR and first principles density functional theory (DFT) study of paramagnetic Mg transition metal oxide systems Mg6MnO8 and MgCr2O4 that serve as model systems for Mg-ion battery cathode materials...
December 5, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27917925/direct-synthesis-of-hydrogen-peroxide-from-plasma-water-interactions
#18
Jiandi Liu, Bangbang He, Qiang Chen, Junshuai Li, Qing Xiong, Guanghui Yue, Xianhui Zhang, Size Yang, Hai Liu, Qing Huo Liu
Hydrogen peroxide (H2O2) is usually considered to be an important reagent in green chemistry since water is the only by-product in H2O2 involved oxidation reactions. Early studies show that direct synthesis of H2O2 by plasma-water interactions is possible, while the factors affecting the H2O2 production in this method remain unclear. Herein, we present a study on the H2O2 synthesis by atmospheric pressure plasma-water interactions. The results indicate that the most important factors for the H2O2 production are the processes taking place at the plasma-water interface, including sputtering, electric field induced hydrated ion emission, and evaporation...
December 5, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27917709/synthesis-of-some-steroidal-derivatives-with-side-chain-of-20-and-22-hydrazone-aromatic-heterocycles-and-their-antiproliferative-acitivity
#19
Chunfang Gan, Liang Liu, Jianguo Cui, Zhiping Liu, Haixin Shi, Qifu Lin, Haibing Sheng, Chunhui Yang, Yanmin Huang
BACKGROUND: The modification of steroidal structure is commonly used to change the biological activity of steroids in medicinal chemistry. Some steroids containing heterocycles exhibit distinct cytotoxicity against various cancer cell lines and have been gotten wide attention over the years by medicinal chemists for drug discovery. METHODS: Using pregnenolone and stigmasterol as starting materials, via different chemical reaction, two series of heterosteroids with side chain of 20- and 22-hydrazone aromatic cycles or heterocycles in their structures were synthesized and characterized by IR, NMR and HRMS...
December 5, 2016: Medicinal Chemistry
https://www.readbyqxmd.com/read/27917399/retinoids-and-retinal-diseases
#20
Philip D Kiser, Krzysztof Palczewski
Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease...
October 2016: Annual Review of Vision Science
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