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Methylene Chloride

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https://www.readbyqxmd.com/read/27846410/a-structural-and-temporal-study-of-the-surfactants-behenyltrimethylammonium-methosulfate-and-behenyltrimethylammonium-chloride-adsorbed-at-air-water-and-air-glass-interfaces-using-sum-frequency-generation-spectroscopy
#1
Sami A Goussous, Mike T L Casford, Simon A Johnson, Paul B Davies
Molecular scale information about the structure of surfactants at interfaces underlies their application in consumer products. In this study the non-linear optical technique of Sum Frequency Generation (SFG) vibrational spectroscopy has been used to investigate the structure and temporal behaviour of two cationic surfactants used frequently in hair conditioners. SFG spectra of films of behenyltrimethylammonium methosulfate (BTMS) and behenyltrimethylammonium chloride (BTAC) were recorded at the air/water interface and on glass slides following Langmuir Blodgett (LB) deposition...
February 15, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27833174/thienyl-difluoroboron-%C3%AE-diketonates-in-solution-and-polylactide-media
#2
Milena Kolpaczynska, Christopher A DeRosa, William A Morris, Cassandra L Fraser
Difluoroboron β-diketonates have impressive optical properties in both solution and the solid state. In particular, both fluorescence and room-temperature phosphorescence are present when the dyes are confined to a rigid matrix, such as poly(lactic acid) (PLA). To expand current knowledge and color range capabilities of this unique type of multi-emitting chromophore, a series of thienyl-substituted BF2bdk complexes have been synthesized. The photophysical properties were investigated in methylene chloride solution and in the solid state as dye/PLA blends...
2016: Australian Journal of Chemistry
https://www.readbyqxmd.com/read/27817926/voc-characteristics-and-inhalation-health-risks-in-newly-renovated-residences-in-shanghai-china
#3
Haixia Dai, Shengao Jing, Hongli Wang, Yingge Ma, Li Li, Weimin Song, Haidong Kan
BACKGROUND: Exposure to indoor VOCs is expected to link to a variety of negative health outcome. The popularity of decorations and refurbishment in homes in China has given rise to indoor elevated VOC levels, potentially posing health threats to residents. METHODS: In this study, concentrations of 101 VOC compounds and associated health risks were investigated in newly renovated homes in Shanghai. The potential excess inhalation health risks from home exposure of 17 health-related VOCs were estimated by the Inhalation Unit Risk (IUR) and Reference Concentration (RfC) proposed by US EPA...
January 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/27808520/organocatalytic-synthesis-of-methylene-bridged-n-heterobiaryls
#4
David E Stephens, Vu T Nguyen, Bhuwan Chhetri, Emily R Clark, Hadi D Arman, Oleg V Larionov
A one-step synthesis of 1,1'- and 2,2'-methylene-bridged N-heterobiaryls directly from the corresponding N-heterocycles in a reaction with methylmagnesium chloride in the presence of catalytic amounts of N,N,N',N'-tetramethylethylenediamine under thermal and microwave conditions is reported. The split-and-merge methylenation of 2,2'-N-heterobiaryls and the direct ortho-alkylation of quinoline and isoquinoline with Grignard reagents have also been developed. Mechanistic studies identified several intermediates and provided insight into the formation and roles of magnesium hydride species in the process...
November 3, 2016: Organic Letters
https://www.readbyqxmd.com/read/27803178/occupational-exposure-to-chlorinated-solvents-and-kidney-cancer-a-case-control-study
#5
Mark P Purdue, Patricia A Stewart, Melissa C Friesen, Joanne S Colt, Sarah J Locke, Misty J Hein, Martha A Waters, Barry I Graubard, Faith Davis, Julie Ruterbusch, Kendra Schwartz, Wong-Ho Chow, Nathaniel Rothman, Jonathan N Hofmann
OBJECTIVES: Trichloroethylene, a chlorinated solvent widely used for metal degreasing, is classified by the International Agency for Research on Cancer as a kidney carcinogen. Other chlorinated solvents are suspected carcinogens, most notably the cleaning solvent perchloroethylene, although it is unclear whether they are associated with kidney cancer. We investigated kidney cancer associations with occupational exposure to 6 chlorinated solvents (trichloroethylene, perchloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, chloroform, and methylene chloride) within a case-control study using detailed exposure assessment methods...
November 1, 2016: Occupational and Environmental Medicine
https://www.readbyqxmd.com/read/27785939/vasorelaxant-action-of-the-chloroform-fraction-of-orthosiphon-stamineusvia-no-cgmp-pathway-potassium-and-calcium-channels
#6
Mun Fei Yam, Chu Shan Tan, Mariam Ahmad, Ruan Shibao
Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O...
October 27, 2016: American Journal of Chinese Medicine
https://www.readbyqxmd.com/read/27785112/in-vitro-vasodilatory-activity-and-possible-mechanisms-of-the-crude-extracts-and-fractions-of-moringa-stenopetala-baker-f-cufod-leaves-in-isolated-thoracic-aorta-of-guinea-pigs
#7
Bekesho Geleta, Eyasu Makonnen, Asfaw Debella, Abiy Abebe, Netsanet Fekadu
Moringa stenopetala, a plant belonging to the family of Moringaceae, is traditionally used for the treatment of hypertension and diabetes in Ethiopia. This study evaluates the in vitro vasodilatory effect of the extract of M. stenopetala leaves and the possible mechanisms in precontracted isolated thoracic aorta of guinea pigs. A guinea pig was sacrificed by gentle cervical dislocation, and the thoracic aortic ring was removed, cut spirally, and mounted in an organ bath containing Krebs-Henseleit physiological solution maintained at 37°C, and then the solution was aerated with carbogen (95% O2 and 5% CO2)...
2016: Journal of Experimental Pharmacology
https://www.readbyqxmd.com/read/27779894/influence-of-sulforaphane-metabolites-on-activities-of-human-drug-metabolizing-cytochrome-p450-and-determination-of-sulforaphane-in-human-liver-cells
#8
Alena Vanduchova, Veronika Tomankova, Pavel Anzenbacher, Eva Anzenbacherova
The influence of metabolites of sulforaphane, natural compounds present in broccoli (Brassica oleracea var. botrytis italica) and in other cruciferous vegetables, on drug-metabolizing cytochrome P450 (CYP) enzymes in human liver microsomes and possible entry of sulforaphane into human hepatic cells were investigated. Metabolites studied are compounds derived from sulforaphane by the mercapturic acid pathway (conjugation with glutathione and by following reactions), namely sulforaphane glutathione and sulforaphane cysteine conjugates and sulforaphane-N-acetylcysteine...
October 25, 2016: Journal of Medicinal Food
https://www.readbyqxmd.com/read/27774729/efficient-methods-for-isolating-five-phytochemicals-from-gentiana-macrophylla-using-high-performance-countercurrent-chromatography
#9
Taewoong Rho, Mila Jung, Min Won Lee, Young-Won Chin, Kee Dong Yoon
Efficient high-performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n-Butanol-soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid (1), swertiamarin (2) and gentiopicroside (3), and a chromene derivative, macrophylloside D (4) which were successfully isolated by flow rate gradient (1.5 mL/min in 0-60 min, 5.0 mL/min in 60-120 min), and consecutive flow rate gradient HPCCC using n-butanol/0...
October 24, 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27771627/anti-inflammatory-activity-of-highly-oxygenated-terpenoids-from-achillea-biebersteinii-afan
#10
Abou El-Hamd H Mohamed, Naglaa S Mohamed, Ahmed R Hamed, Mohamed-Elamir F Hegazy
In continuation of our chemical investigation on some medicinal plants of the genus Achillea, chromatographic investigation of the methylene chloride/methanol (1:1) extract of the air-dried aerial part of Achillea biebersteinii Afan. (family Asteraceae) afforded a new natural monoterpene (2), in addition to two known sesquiterpenes (3 and 4). Compound 1 was isolated as light needle crystals. Structures were established on the basis of MS and NMR spectroscopic (1H, 13C, 1H-1H correlation spectroscopy, heteronuclear multiple-quantum coherence and heteronuclear multiple-bond correlation) data and in case of compound 1 were confirmed by X-ray analysis...
October 24, 2016: Zeitschrift Für Naturforschung. C, A Journal of Biosciences
https://www.readbyqxmd.com/read/27744700/order-of-magnitude-dissociative-ionization-enhancement-observed-for-pulses-with-high-order-dispersion
#11
Muath Nairat, Vadim V Lozovoy, Marcos Dantus
While the interaction of atoms in strong fields is well understood, the same cannot be said about molecules. We consider how dissociative ionization of molecules depends on the quality of the femtosecond laser pulses, in particular, the presence of third- and fourth-order dispersion. We find that high-order dispersion (HOD) unexpectedly results in order-of-magnitude enhanced ion yields, along with the factor of three greater kinetic energy release compared to transform-limited pulses with equal peak intensities...
October 16, 2016: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/27703124/crystallization-experiments-with-the-dinuclear-chelate-ring-complex-di-%C3%AE-chlorido-bis-%C3%AE-2-2-allyl-4-methoxy-5-propan-2-yloxy-carbonyl-methoxy-phenyl-%C3%AE%C2%BAc-1-platinum-ii
#12
Chi Nguyen Thi Thanh, Thong Pham Van, Hai Le Thi Hong, Luc Van Meervelt
Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)], [Pt2(C15H19O4)2Cl2], containing a derivative of the natural compound eugenol as ligand, have been performed. Using five different sets of crystallization conditions resulted in four different complexes which can be further used as starting compounds for the synthesis of Pt complexes with promising anticancer activities. In the case of vapour diffusion with the binary chloroform-diethyl ether or methylene chloride-diethyl ether systems, no change of the molecular structure was observed...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
https://www.readbyqxmd.com/read/27700076/stereoselective-synthesis-of-methylene-oxindoles-via-palladium-ii-catalyzed-intramolecular-cross-coupling-of-carbamoyl-chlorides
#13
Christine M Le, Theresa Sperger, Rui Fu, Xiao Hou, Yong Hwan Lim, Franziska Schoenebeck, Mark Lautens
We report a highly robust, general and stereoselective method for the synthesis of 3-(chloromethylene)oxindoles from alkyne-tethered carbamoyl chlorides using PdCl2(PhCN)2 as the catalyst. The transformation involves a stereo- and regioselective chloropalladation of an internal alkyne to generate a nucleophilic vinyl Pd(II) species, which then undergoes an intramolecular cross-coupling with a carbamoyl chloride. The reaction proceeds under mild conditions, is insensitive to the presence of moisture and air, and is readily scalable...
October 4, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27599129/novel-dextran-derivatives-with-unconventional-structure-formed-in-an-efficient-one-pot-reaction
#14
Konrad Hotzel, Thomas Heinze
An efficient one-pot synthesis of new dextran derivatives is described. The functional groups of β-alanine, i.e., the carboxyl- and amine group, are converted independently in one-step by iminium chloride to form products with a single substituent. The dextran N-[(dimethylamino)methylene]-β-alanine ester is formed selectively. The structure of the resulting polymers is unambiguously determined by means of NMR- and FTIR-spectroscopy and elemental analysis.
August 27, 2016: Carbohydrate Research
https://www.readbyqxmd.com/read/27592244/volatiles-of-solena-amplexicaulis-lam-gandhi-leaves-influencing-attraction-of-two-generalist-insect-herbivores
#15
Nupur Sarkar, Amarnath Karmakar, Anandamay Barik
Epilachna vigintioctopunctata Fabr. (Coleoptera: Coccinellidae) and Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) are important pests of Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae), commonly known as creeping cucumber. The profiles of volatile organic compounds from undamaged plants, plants after 48 hr continuous feeding of adult females of either E. vigintioctopunctata or A. foveicollis, by adults of both species, and after mechanical damaging were identified and quantified by GC-MS and GC-FID analyses...
September 3, 2016: Journal of Chemical Ecology
https://www.readbyqxmd.com/read/27576736/filaricidal-activities-on-onchocerca-ochengi-and-loa-loa-toxicity-and-phytochemical-screening-of-extracts-of-tragia-benthami-and-piper-umbellatum
#16
Fidelis Cho-Ngwa, Elvis Monya, Boris K Azantsa, Faustin Pascal T Manfo, Smith B Babiaka, James A Mbah, Moses Samje
BACKGROUND: Onchocerciasis is the world's second leading infectious cause of blindness. Its control is currently hampered by the lack of a macrofilaricidal drug and by severe adverse events observed when the lone recommended microfilaricide, ivermectin is administered to individuals co-infected with Loa loa. Therefore, there is the need for a safe and effective macrofilaricidal drug that will be able to cure the infection and break transmission cycles, or at least, an alternative microfilaricide that does not kill L...
2016: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/27574817/ligand-exchange-mediated-activation-and-stabilization-of-a-re-based-olefin-metathesis-catalyst-by-chlorinated-alumina
#17
Alessandro Gallo, Anthony Fong, Kai C Szeto, Julia Rieb, Laurent Delevoye, Régis M Gauvin, Mostafa Taoufik, Baron Peters, Susannah L Scott
Extensive chlorination of γ-Al2O3 results in the formation of highly Lewis acidic surface domains depleted in surface hydroxyl groups. Adsorption of methyltrioxorhenium (MTO) onto these chlorinated domains serves to activate it as a low temperature, heterogeneous olefin metathesis catalyst and confers both high activity and high stability. Characterization of the catalyst reveals that the immobilized MTO undergoes partial ligand exchange with the surface, whereby some Re sites acquire a chloride ligand from the modified alumina while donating an oxo ligand to the support...
October 5, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27537923/novel-bis-arylalkylamines-as-myeloperoxidase-inhibitors-design-synthesis-and-structure-activity-relationship-study
#18
Iyas Aldib, Michel Gelbcke, Jalal Soubhye, Martine Prévost, Paul G Furtmüller, Christian Obinger, Betina Elfving, Ibaa Chikh Alard, Goedele Roos, Cédric Delporte, Gilles Berger, Damien Dufour, Karim Zouaoui Boudjeltia, Jean Nève, Francois Dufrasne, Pierre Van Antwerpen
Human myeloperoxidase (MPO) plays an important role in innate immunity but also aggravates tissue damage by oxidation of biomolecules at sites of inflammation. As a result from a recent high-throughput virtual screening approach for MPO inhibitors, bis-2,2'-[(dihydro-1,3(2H,4H) pyrimidinediyl)bis(methylene)]phenol was detected as a promising lead compound for inhibition of the MPO-typical two-electron oxidation of chloride to hypochlorous acid (IC50 = 0.5 μM). In the present pharmacomodulation study, 37 derivatives of this lead compound were designed and synthesized driven by comprehensive docking studies and the impact on the chlorination activity of MPO...
November 10, 2016: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/27523328/kinetic-energy-release-of-the-singly-and-doubly-charged-methylene-chloride-molecule-the-role-of-fast-dissociation
#19
K F Alcantara, A B Rocha, A H A Gomes, W Wolff, L Sigaud, A C F Santos
The center of mass kinetic energy release distribution (KERD) spectra of selected ionic fragments, formed through dissociative single and double photoionization of CH2Cl2 at photon energies around the Cl 2p edge, were extracted from the shape and width of the experimentally obtained time-of-flight (TOF) distributions. The KERD spectra exhibit either smooth profiles or structures, depending on the moiety and photon energy. In general, the heavier the ionic fragments, the lower their average KERDs are. In contrast, the light H(+) fragments are observed with kinetic energies centered around 4...
September 1, 2016: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/27497006/effective-methylation-of-phosphonic-acids-related-to-chemical-warfare-agents-mediated-by-trimethyloxonium-tetrafluoroborate-for-their-qualitative-detection-and-identification-by-gas-chromatography-mass-spectrometry
#20
Carlos A Valdez, Roald N Leif, Armando Alcaraz
The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found to be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (∼10 μg mL(-1))...
August 24, 2016: Analytica Chimica Acta
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