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https://www.readbyqxmd.com/read/28636753/stable-bromiranium-ions-with-weakly-coordinating-counterions-as-efficient-electrophilic-brominating-agents
#1
Christoph Ascheberg, Jonathan Bock, Florenz Buß, Christian Mück-Lichtenfeld, Constantin B Daniliuc, Klaus Bergander, Fabian Dielmann, Ulrich Hennecke
Electrophilic halogenating agents are an important class of reagents in chemical synthesis. Herein, we show that sterically demanding bromiranium ions with weakly coordinating counterions are highly reactive electrophilic brominating agents. Despite their high reactivity these reagents are stable, in one case even under ambient conditions and can be applied in electrophilic halogenations of alkenes as well as heteroatoms.
June 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28624672/analysis-of-fire-deaths-in-poland-and-influence-of-smoke-toxicity
#2
Joanna Giebułtowicz, Monika Rużycka, Piotr Wroczyński, David A Purser, Anna A Stec
Dwelling fires have changed over the years because building contents and the materials used in then have changed. They all contribute to an ever-growing diversity of chemical species found in fires, many of them highly toxic. These arise largely from the changing nature of materials in interior finishes and furniture, with an increasing content of synthetic materials containing higher levels of nitrogen, halogen and phosphorus additives. While there is still a belief that carbon monoxide is the major lethal toxic agent in fires, the hydrogen cyanide and acid gases released from these additives are now well-recognised as major contributory causes of incapacitation, morbidity and mortality in domestic fires...
June 9, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28607510/asymmetric-suzuki-miyaura-coupling-of-heterocycles-via-rhodium-catalysed-allylic-arylation-of-racemates
#3
Philipp Schäfer, Thomas Palacin, Mireia Sidera, Stephen P Fletcher
Using asymmetric catalysis to simultaneously form carbon-carbon bonds and generate single isomer products is strategically important. Suzuki-Miyaura cross-coupling is widely used in the academic and industrial sectors to synthesize drugs, agrochemicals and biologically active and advanced materials. However, widely applicable enantioselective Suzuki-Miyaura variations to provide 3D molecules remain elusive. Here we report a rhodium-catalysed asymmetric Suzuki-Miyaura reaction with important partners including aryls, vinyls, heteroaromatics and heterocycles...
June 13, 2017: Nature Communications
https://www.readbyqxmd.com/read/28586202/cytosine-iminyl-radical-cytn%C3%A2-formation-via-electron-induced-debromination-of-5-bromocytosine-a-dft-and-gaussian-4-study
#4
Anil Kumar, Michael D Sevilla
Halogen-substituted pyrimidines, such as 5-bromouracil and 5-iodouracil, have been used as radio therapeutic (RT) agents in cancer treatment. The radiosensitizer activity of 5-bromouracil is attributed to its reaction with electron which produce the highly reactive uracil-5-yl radical by dissociating the C5-Br bond. Using density functional methods and highly accurate Gaussian 4 (G4) theory, herein, we show that 5-bromocytosine (5-Brcyt) after reaction with electron, also, leads to the formation of cytosine-5-yl radical...
June 6, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28585822/size-shape-and-phase-control-in-ultrathin-cdse-nanosheets
#5
Frauke Gerdes, Cristina Navío, Beatriz H Juárez, Christian Klinke
Ultrathin two-dimensional nanosheets raise a rapidly increasing interest due to their unique dimensionality-dependent properties. Most of the two-dimensional materials are obtained by exfoliation of layered bulk materials or are grown on substrates by vapor deposition methods. To produce free-standing nanosheets, solution-based colloidal methods are emerging as promising routes. In this work, we demonstrate ultrathin CdSe nanosheets with controllable size, shape, and phase. The key of our approach is the use of halogenated alkanes as additives in a hot-injection synthesis...
June 8, 2017: Nano Letters
https://www.readbyqxmd.com/read/28585445/lactose-esters-synthesis-and-biotechnological-applications
#6
Jakub Staroń, Janusz M Dąbrowski, Ewelina Cichoń, Maciej Guzik
Biodegradable nonionic sugar esters-based surfactants have been gaining more and more attention in recent years due to their chemical plasticity that enables the various applications of these molecules. In this review, various synthesis methods and biotechnological implications of lactose esters (LEs) uses are considered. Several chemical and enzymatic approaches are described for the synthesis of LEs, together with their applications, i.e. function in detergents formulation and as additives that not only stabilize food products but also protect food from undesired microbial contamination...
June 6, 2017: Critical Reviews in Biotechnology
https://www.readbyqxmd.com/read/28576279/-atypical-reaction-to-anesthesia-in-duchenne-becker-muscular-dystrophy
#7
Helga Cristina Almeida da Silva, Marcia Hiray, Mariz Vainzof, Beny Schmidt, Acary Souza Bulle Oliveira, José Luiz Gomes do Amaral
BACKGROUND AND OBJECTIVES: Duchenne/Becker muscular dystrophy affects skeletal muscles and leads to progressive muscle weakness and risk of atypical anesthetic reactions following exposure to succinylcholine or halogenated agents. The aim of this report is to describe the investigation and diagnosis of a patient with Becker muscular dystrophy and review the care required in anesthesia. CASE REPORT: Male patient, 14 years old, referred for hyperCKemia (chronic increase of serum creatine kinase levels - CK), with CK values of 7,779-29,040IU...
May 30, 2017: Revista Brasileira de Anestesiologia
https://www.readbyqxmd.com/read/28521262/rhodium-catalyzed-c-h-bond-activation-for-the-synthesis-of-quinonoid-compounds-significant-anti-trypanosoma-cruzi-activities-and-electrochemical-studies-of-functionalized-quinones
#8
Guilherme A M Jardim, Thaissa L Silva, Marilia O F Goulart, Carlos A de Simone, Juliana M C Barbosa, Kelly Salomão, Solange L de Castro, John F Bower, Eufrânio N da Silva Júnior
Thirty four halogen and selenium-containing quinones, synthesized by rhodium-catalyzed C-H bond activation and palladium-catalyzed cross-coupling reactions, were evaluated against bloodstream trypomastigotes of T. cruzi. We have identified fifteen compounds with IC50/24 h values of less than 2 μM. Electrochemical studies on A-ring functionalized naphthoquinones were also performed aiming to correlate redox properties with trypanocidal activity. For instance, (E)-5-styryl-1,4-naphthoquinone 59 and 5,8-diiodo-1,4-naphthoquinone 3, which are around fifty fold more active than the standard drug benznidazole, are potential derivatives for further investigation...
May 4, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28516256/-skin-diseases-associated-with-environmental-factors
#9
REVIEW
Vera Mahler
BACKGROUND: Multiple environmental exposures may derange the regulatory and repair mechanisms of the skin and lead to dermatological disease. OBJECTIVES: Provide an overview of non-allergic skin diseases associated with environmental factors. MATERIALS AND METHODS: Review of current scientific evidence for associations of non-allergic skin diseases with environmental exposures: irritation, chemicals, infection, UV-radiation, temperature. RESULTS: Predisposition (constitution e...
June 2017: Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz
https://www.readbyqxmd.com/read/28515440/a-highly-potent-class-of-halogenated-phenazine-antibacterial-and-biofilm-eradicating-agents-accessed-through-a-modular-wohl-aue-synthesis
#10
Hongfen Yang, Yasmeen Abouelhassan, Gena M Burch, Dimitris Kallifidas, Guangtao Huang, Hussain Yousaf, Shouguang Jin, Hendrik Luesch, Robert W Huigens
Unlike individual, free-floating planktonic bacteria, biofilms are surface-attached communities of slow- or non-replicating bacteria encased within a protective extracellular polymeric matrix enabling persistent bacterial populations to tolerate high concentrations of antimicrobials. Our current antibacterial arsenal is composed of growth-inhibiting agents that target rapidly-dividing planktonic bacteria but not metabolically dormant biofilm cells. We report the first modular synthesis of a library of 20 halogenated phenazines (HP), utilizing the Wohl-Aue reaction, that targets both planktonic and biofilm cells...
May 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28500969/oxidation-of-the-antibacterial-agent-norfloxacin-during-sodium-hypochlorite-disinfection-of-marine-culture-water
#11
Yuanyuan Zhang, Chuan Rong, Yanqun Song, Yinghui Wang, Jiying Pei, Xinying Tang, Ruijie Zhang, Kefu Yu
Chlorination disinfection and antibiotic addition are two universal processes of marine culture. The generation of disinfection byproducts (DBPs) is unavoidable. Antibiotic residue not only pollutes water but also acts as a precursor to the production of new DBPs. The fate of antibiotic norfloxacin (NOR) in chlorination disinfection was investigated. It was observed that NOR could be oxidized by disinfection agent sodium hypochlorite, but the oxidation rate varied considerably with the type of disinfected water...
May 7, 2017: Chemosphere
https://www.readbyqxmd.com/read/28499825/induction-of-cytochrome-p450-dependent-mixed-function-oxidase-activities-and-peroxisome-proliferation-by-chloramine-t-in-male-rat-liver
#12
María-Aránzazu Martínez, Irma Ares, Jose-Luís Rodríguez, Marta Martínez, María-Rosa Martínez-Larrañaga, Arturo Anadón
Chloramine-T is an antimicrobial agent recognized for its disinfectant properties widely used in food industry. As an N-chloro-compound, chloramine-T contains electrophilic chlorine and in water it hydrolyses to hypochlorite. Chlorine as hypochlorous acid or hypochlorite is a very reactive chemical which can function as both an oxidant and halogenating agent. Because chloramine-T could be involved in the metabolic activation of drugs, in the present study the effects of chloramine-T on the activities of some drug metabolizing enzymes in rat liver microsomes and peroxisome proliferation were determined in vivo...
May 9, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28487818/modeling-adsorption-of-brominated-chlorinated-and-mixed-bromo-chloro-dibenzo-p-dioxins-on-c60-fullerene-using-nano-qspr
#13
Piotr Urbaszek, Agnieszka Gajewicz, Celina Sikorska, Maciej Haranczyk, Tomasz Puzyn
Many technological implementations in the field of nanotechnology have involved carbon nanomaterials, including fullerenes such as the buckminsterfullerene, C60. The unprecedented properties of such organic nanomaterials (in particular their large surface area) gained extensive attention for their potential use as organic pollutant sorbents. Sorption interactions can be very hazardous and useful at the same time. This work investigates the influence of halogenation by bromine and/or chlorine in dibenzo-p-dioxins on their sorption ability on the C60 fullerene surface...
2017: Beilstein Journal of Nanotechnology
https://www.readbyqxmd.com/read/28487674/uncovering-potential-applications-of-cyanobacteria-and-algal-metabolites-in-biology-agriculture-and-medicine-current-status-and-future-prospects
#14
REVIEW
Rachana Singh, Parul Parihar, Madhulika Singh, Andrzej Bajguz, Jitendra Kumar, Samiksha Singh, Vijay P Singh, Sheo M Prasad
Cyanobacteria and algae having complex photosynthetic systems can channelize absorbed solar energy into other forms of energy for production of food and metabolites. In addition, they are promising biocatalysts and can be used in the field of "white biotechnology" for enhancing the sustainable production of food, metabolites, and green energy sources such as biodiesel. In this review, an endeavor has been made to uncover the significance of various metabolites like phenolics, phytoene/terpenoids, phytols, sterols, free fatty acids, photoprotective compounds (MAAs, scytonemin, carotenoids, polysaccharides, halogenated compounds, etc...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28480028/a-comparison-of-renal-responses-to-sevoflurane-and-isoflurane-in-patients-undergoing-donor-nephrectomy-a-randomized-controlled-trial
#15
Lady Christine L Ong Sio, Richard Glenn C Dela Cruz, Alexander F Bautista
Sevoflurane and isoflurane are volatile halogenated ether widely used in anesthesia. Both have comparable potency and easy titratability but sevoflurane has lower pungency and results in faster patient recovery. Isoflurane, however, is more affordable. The nephrotoxicity of sevoflurane is undisputed but studies on isoflurane nephrotoxicity are lacking. The objective of this paper is to determine the overall nephrotoxicity profile of sevoflurane and isoflurane in donor nephrectomy patients using the renal function markers - nuclear glomerular filtration rate (GFR), serum creatinine, urine protein-to-creatinine ratio, proteinuria, and glucosuria...
January 2017: Medical Gas Research
https://www.readbyqxmd.com/read/28467047/electrophilic-halogenation-of-closo-1-2-c2b8h10
#16
Mario Bakardjiev, Aleš Růžička, Zdeňka Růžičková, Josef Holub, Oleg L Tok, Bohumil Štíbr
Initial studies on electrophilic halogenation of the dicarbaborane closo-1,2-C2B8H10 (1) have been carried out to reveal that the substitution takes place at B7 and B10 vertexes, which are the most removed from the CH positions. The course of the halogenation is strongly dependent on the nature of the halogenation agent and reaction conditions. Individual reactions led to the isolation of the monosubstituted compounds 1,2-C2B8H9-10-X (2) (where X = F, I) and 1,2-C2B8H9-7-X (3) (where X = Cl, I). Disubstituted carboranes 1,2-C2B8H8-7,10-X2 (4) (where X = Cl, Br, I) were obtained under more forcing conditions...
May 3, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28402644/investigation-of-the-halogenate-hydrogen-peroxide-reactions-using-the-electron-paramagnetic-resonance-spin-trapping-technique
#17
Maja C Pagnacco, Miloš D Mojović, Ana D Popović-Bijelić, Attila K Horváth
The differences in the mechanism of the halogenate reactions with the same oxidizing/reducing agent, such as H2O2 contribute to the better understanding of versatile halogen chemistry. The reaction between iodate, bromate, and chlorate with hydrogen peroxide in acidic medium at 60 °C is investigated by using the electron paramagnetic resonance (EPR) spin trapping technique. Essential differences in the chemistry of iodate, bromate, and chlorate in their reactions with hydrogen peroxide have been evidenced by finding different radicals as governing intermediates...
May 4, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28384544/design-synthesis-and-structure-activity-relationship-study-of-halogen-containing-2-benzylidene-1-indanone-derivatives-for-inhibition-of-lps-stimulated-ros-production-in-raw-264-7-macrophages
#18
Aarajana Shrestha, Hye Jin Oh, Mi Jin Kim, Nirmala Tilija Pun, Til Bahadur Thapa Magar, Ganesh Bist, Hongseok Choi, Pil-Hoon Park, Eung-Seok Lee
As a continuous effort to discover new potential anti-inflammatory agents, we systematically designed and synthesized sixty-one 2-benzylidene-1-indanone derivatives with structural modification of chalcone, and evaluated their inhibitory activity on LPS-stimulated ROS production in RAW 264.7 macrophages. Systematic structure-activity relationship study revealed that hydroxyl group in C-5, C-6, or C-7 position of indanone moiety, and ortho-, meta-, or para-fluorine, trifluoromethyl, trifluoromethoxy, and bromine functionalities in phenyl ring are important for inhibition of ROS production in LPS-stimulated RAW 264...
March 27, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28380119/synthesis-and-biological-evaluation-of-novel-imidazolidine-derivatives-as-candidates-to-schistosomicidal-agents
#19
Thiago José Matos-Rocha, Maria do Carmo Alves de Lima, Anekécia Lauro da Silva, Jamerson Ferreira de Oliveira, Allana Lemos Andrade Gouveia, Vinícius Barros Ribeiro da Silva, Antônio Sérgio Alves de Almeida, Fábio André Brayner, Pablo Ramon Gualberto Cardoso, Marina da Rocha Pitta-Galdino, Ivan da Rocha Pitta, Moacyr Jesus Barreto de Melo Rêgo, Luiz Carlos Alves, Maira Galdino da Rocha Pitta
Introduction: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives. Material and methods: We synthesized two novel imidazolidine derivatives: (LPSF/PTS10) (Z)-1-(2-chloro-6-fluorobenzyl)-4-(4-dimethylaminobenzylidene)-5-thioxoimidazolidin-2-one and (LPSF/PTS23) (Z)-1-(2-chloro-6-fluoro-benzyl)-5-thioxo-4-(2,4,6-trimethoxy-benzylidene)-imidazolidin-2-one...
April 3, 2017: Revista do Instituto de Medicina Tropical de São Paulo
https://www.readbyqxmd.com/read/28373861/environmental-issues-in-thyroid-diseases
#20
REVIEW
Silvia Martina Ferrari, Poupak Fallahi, Alessandro Antonelli, Salvatore Benvenga
Environmental factors are determinant for the appearance of autoimmune thyroid diseases (AITD) in susceptible subjects. Increased iodine intake, selenium, and vitamin D deficiency, exposure to radiation, from nuclear fallout or due to medical radiation, are environmental factors increasing AITD. Cigarette smoking is associated with Graves' disease and Graves' ophthalmopathy, while it decreases the risk of hypothyroidism and thyroid autoimmunity. Viral infections are important environmental factors in the pathogenesis of AITD, too, particularly human parvovirus B19 (EVB19) and hepatitis C virus...
2017: Frontiers in Endocrinology
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