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Miran Brvar, Ming Yin Chan, Andrew H Dawson, Richard R Ribchester, Michael Eddleston
INTRODUCTION: Treatment of acute organophosphorus or carbamate insecticide self-poisoning is often ineffective, with tens of thousands of deaths occurring every year. Researchers have recommended the addition of magnesium sulfate or calcium channel blocking drugs to standard care to reduce acetylcholine release at cholinergic synapses. OBJECTIVE: We aimed to review systematically the evidence from preclinical studies in animals exposed to organophosphorus or carbamate insecticides concerning the efficacy of magnesium sulfate and calcium channel blocking drugs as therapy compared with placebo in reducing mortality or clinical features of poisoning...
March 20, 2018: Clinical Toxicology
Yi Zhou, Qingqing Chang, Wenjie Wang, Xiaofang Zhang, Fang Zhou, Jianguo Sun, Guangji Wang, Ying Peng
FY363 is a new chemical entity of gemcitabine analog, which has been shown to have a significant inhibitory effect on cell proliferation in a variety of tumor cell lines in vitro. As a carbamate derivative, FY363 would be converted to the active metabolite gemcitabine through enzyme action in vivo. In order to clarify the exposure of FY363 prototype and its metabolite gemcitabine in vivo after administration of FY363, a sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and validated to simultaneously determine FY363 and gemcitabine in rat plasma after liquid-liquid extraction with ethyl acetate...
March 14, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Amy E Kalkbrenner, Gayle C Windham, Cheng Zheng, Rob McConnell, Nora L Lee, James J Schauer, Brian Thayer, Juhi Pandey, Heather E Volk
BACKGROUND: Previous studies have reported associations of perinatal exposure to air toxics, including some metals and volatile organic compounds, with autism spectrum disorder (ASD). OBJECTIVES: Our goal was to further explore associations of perinatal air toxics with ASD and associated quantitative traits in high-risk multiplex families. METHODS: We included participants of a U.S. family-based study [the Autism Genetic Resource Exchange (AGRE)] who were born between 1994 and 2007 and had address information...
March 12, 2018: Environmental Health Perspectives
Sindhu Kancherla, Marianne Lorentzen, Victor Snieckus, Kåre Bredeli Jørgensen
A general method for the regioselective synthesis of a series of ortho-substituted chrysenyl N,N-diethyl-O-carbamates by the directed ortho metalation (DoM) strategy is reported. The starting O-carbamates were prepared from corresponding chrysenols, available by oxidative photochemical cyclization or directed remote metalation tactics. Chrysen-1-yl and chrysene-3-yl ring site selectivity of directed ortho metalation (DoM) and anionic ortho Fries rearrangement (AoF) protocols, with s-BuLi/TMEDA, followed by electrophilic quench using a selection of electrophiles, were observed leading to new chrysenyl derivatives...
March 15, 2018: Journal of Organic Chemistry
Peng Zhang, Xing Hu
Urea is an important precursor of the harmful carcinogenic product ethyl carbamate in fermented wines. To decipher more fully the contributions of three arginine permeases, Can1p, Gap1p and Alp1p in urea formation, various engineered strains were examined for their ability to form urea. This included seven mutants with different combinations of permease deficiency and grown in both simple and more complex media, and the wild-type strain modified to overexpress the three arginine permeases. A truncated GATA transcription factor, Gln3p1-653 , was also overexpressed in the arginine permease deficient mutants to determine whether the permeases have a synergistic effect on urea formation with other urea reducing modules...
March 13, 2018: World Journal of Microbiology & Biotechnology
Marek Bajda, Kamil Łątka, Michalina Hebda, Jakub Jończyk, Barbara Malawska
Selective butyrylcholinesterase inhibitors could be the promising drug candidates, used in treatment of Alzheimer's disease. The study describes the synthesis and biological activity of novel carbamate derivatives with N-phenylpiperazine, N-benzylpiperazine and 4-benzylpiperidine moieties. Biological studies revealed that most of these compounds displayed significant activity against BuChE. Compound 16 (3-(4-phenyl-piperazin-1-ylmethyl)-phenyl phenylcarbamate) turned out to be the most active (IC50  = 2...
March 3, 2018: Bioorganic Chemistry
Teemu Niemi, Israel Fernández, Bethany Steadman, Jere K Mannisto, Timo Repo
We report herein a straightforward general method for the synthesis of cyclic carbamates from amino alcohols and carbon dioxide in the presence of an external base and a hydroxyl group activating reagent. Utilizing p-toluenesulfonyl chloride (TsCl), the reaction proceeds under mild conditions, and the approach is fully applicable to the preparation of various high value-added 5- and 6-membered rings as well as bicyclic fused ring carbamates. DFT calculations and experimental results indicate a SN 2-type reaction mechanism with high regio-, chemo-, and stereoselectivity...
March 12, 2018: Chemical Communications: Chem Comm
Eric Tan, Ophélie Quinonero, M Elena de Orbe, Antonio M Echavarren
We report the alkynylation of C(sp2 )-H bonds with bromoalkynes (inverse-Sonogashira reaction) directed by synthetically useful ester, ketone, and ether groups under rhodium catalysis. Other less common directing groups such as amine, thioether, sulfoxide, sulfone, phenol ester, and carbamate are also suitable directing groups. Mechanistic studies indicate that the reaction proceeds by a turnover-limiting C-H activation step via an electrophilic-type substitution.
March 2, 2018: ACS Catalysis
Shuang Ma, Huiyi Zhang, Rafaël J Sablong, Cor E Koning, Rolf A T M van Benthem
t-Butyl-oxycarbonylated diamines ("di-Boc-carbamates") are investigated as dicarbamate monomers for diamine/dicarbamate polymerizations. Polyureas (PUs) and polyurethanes (PURs) with high molecular weights are prepared from stoichiometric polymerizations of diamines or diols with N-N'-di-t-butyl-oxycarbonyl isophorone diamine (DiBoc-IPDC) using KOt-Bu as a catalyst, while gelation is observed when an excess of DiBoc-IPDC is used with respect to the diamines or diols. Stable dispersions are obtained from PUs and PURs with 3,3'-diamino-N-methyldipropylamine (DMDPA) as internal dispersing agent...
March 8, 2018: Macromolecular Rapid Communications
Hang Huo, Xianzhu Xu, Tingting Zhao, Yudong Li, Yanqiu Jiang, Kaifeng Lin
Hybrid molecularly imprinted mesoporous silicas were synthesized by co-condensation of tetraethoxysilane and functional organosilica precursors of HQP and BPAP, in which hydroquinone (HQ) and bisphenol A (BPA) were linked as imprinting molecules. Owing to the existence of a thermally reversible covalent bond of carbamate (-NH-COO-), the imprinting molecules could be eliminated under thermal treatment and molecularly imprinted cavities were formed in the framework wall. All of these materials were used to catalyze heterogeneous Knoevenagel reactions and proved to exhibit higher catalytic conversion and turnover frequency (TOF) number compared with the materials with imprinting molecules, which is attributed to the presence of amino groups with higher basicity and molecularly imprinted cavities...
March 5, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Elisabeth Speckmeier, Michael Klimkait, Kirsten Zeitler
Orthogonal protection and deprotection of amines remain important tools in synthetic design as well as in chemical biology and material research applications. A robust, highly efficient and sustainable method for the formation of phenacyl based carbamate esters has been developed using CO2 for the in situ preparation of the intermediate carbamates. Our mild and broadly applicable protocol allows for the formation of phenacyl urethanes of anilines, primary amines, including amino acids, and secondary amines in high to excellent yields...
March 5, 2018: Journal of Organic Chemistry
Francesca Citossi, Thomas Smith, Jong Bong Lee, Joel Segal, Pavel Gershkovich, Michael John Stocks, Tracey D Bradshaw, Barrie Kellam, Maria Marlow
Low molecular weight gelators (LMWGs) of chemotherapeutic drugs represent a valid alternative to the existing poly-mer-based formulations used for targeted delivery of anticancer drugs. Herein we report the design and development of novel self-assembling gelators of the antitumour benzothiazole 5F 203 (1). Two different types of derivatives of 1 were synthesized, formed by an amide (2) and a carbamate (3a-3d) linker, respectively, which showed potent in vitro anti-tumour activity against MCF-7 mammary and IGROV-1 ovarian carcinoma cells...
March 5, 2018: Molecular Pharmaceutics
Dounin Danielle Zoh, Ludovic Phamien Ahoua Alou, Mahama Toure, Cédric Pennetier, Soromane Camara, Dipomin François Traore, Alphonsine Amanan Koffi, Akré Maurice Adja, Ahoua Yapi, Fabrice Chandre
BACKGROUND: Several studies were carried out in experimental hut station in areas surrounding the city of Bouaké, after the crisis in Côte d'Ivoire. They reported increasing resistance levels to insecticide for malaria transmiting mosquitoes. The present work aims to evaluate the current resistance level of An. gambiae (s.l.) in rural and urban areas in the city of Bouaké. METHODS: Larvae of Anopheles gambiae (s.l.) were collected from five different study sites and reared to adult stages...
March 2, 2018: Parasites & Vectors
Christopher A Hammer, Konstantin Falahati, Andreas Jakob, Robin Klimek, Irene Burghardt, Alexander Heckel, Josef Wachtveitl
Here we report the design of a new coumarin-based photolabile protecting group with enhanced two-photon absorption. Two-photon excited fluorescence (TPEF), color-tuned ultrafast transient absorption spectroscopy and infrared (IR) measurements are employed to photochemically characterize the newly designed ATTO 390-DEACM-cargo triad. Increased two-photon cross-section values of the novel cage in comparison to the widely used protecting group DEACM ([7-(diethylamino)coumarin-4-yl]methyl) are extracted from TPEF experiments...
March 2, 2018: Journal of Physical Chemistry Letters
Laura A McAllister, Christopher R Butler, Scot Mente, Steven V O'Neil, Kari R Fonseca, Justin R Piro, Julie A Cianfrogna, Timothy L Foley, Adam M Gilbert, Anthony R Harris, Christopher J Helal, Douglas S Johnson, Justin I Montgomery, Deane M Nason, Stephen Noell, Jayvardhan Pandit, Bruce N Rogers, Tarek A Samad, Christopher L Shaffer, Rafael Guimaraes da Silva, Daniel P Uccello, Damien Webb, Michael A Brodney
Monoacylglycerol lipase (MAGL) inhibition provides a potential treatment approach to neuroinflammation through modulation of both the endocannabinoid pathway, and arachidonoyl signaling in the central nervous system (CNS). Herein we report the discovery of compound 15 (PF-06795071), a potent and selective covalent MAGL inhibitor, featuring a novel trifluoromethyl glycol leaving group which confers significant physicochemical property improvements as compared with earlier inhibitor series with more lipophilic leaving groups...
March 2, 2018: Journal of Medicinal Chemistry
Sulaiman S Ibrahim, Nathalie Amvongo-Adjia, Murielle J Wondji, Helen Irving, Jacob M Riveron, Charles S Wondji
Resistance to pyrethroids (the ingredients in bed net insecticides) in the major malaria vector Anopheles funestus is threatening recent gains in the fight against malaria. Here, we established the role of an over-expressed P450, A. funestus CYP6AA1 in insecticides resistance. Transcription profiling of CYP6AA1 across Africa using microarray and quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that it is significantly more over-expressed in southern African populations compared to West (Benin) and East African (Uganda)...
March 2, 2018: Genes
Molly C Goodier, Sanna D Ronkainen, Sara A Hylwa
BACKGROUND: Rubber accelerators play a significant role in glove-related occupational contact dermatitis, especially among health care workers. Currently, there is limited information readily available outlining the accelerators used in specific medical examination and surgical gloves. OBJECTIVE: The aim of this study was to ascertain the accelerators used in medical examination and surgical gloves for major glove manufacturers within the United States. METHODS: An initial Internet-based search was performed to establish relevant manufacturers and product lines, with subsequent inquiry with each corresponding company regarding accelerators used in each medical and surgical glove line...
February 28, 2018: Dermatitis
Romina Wechsel, Matej Zabka, John W Ward, Jonathan Clayden
Symmetrical oligourea foldamers were made from meso cyclohexane-1,2-diamine and desymmetrised by incorporating terminal functional groups (carbamates, ureas or thioureas) with differing hydrogen-bonding capacities. The molecules adopt two alternative conformers whose relative population is determined entirely by the terminal functional groups, with the competing hydrogen-bonding properties of these groups dictating the foldamer's global hydrogen-bond directionality. Intermolecular association of these dynamic foldamers with anionic guests (acetate, phosphate) leads to inversion of the hydrogen-bond directionality and consequently a detectable change in screw-sense preference...
March 1, 2018: Journal of the American Chemical Society
Elwira Bisz, Michal Szostak
Iron-catalyzed cross-coupling reactions allow for sustainable formation of C-C bonds using cost-effective, earth-abundant base-metal catalysis in complex areas of pharmaceutical development, natural product and fine chemical synthesis. The major challenge to maintain full sustainability of the process is the identification of green and renewable solvents that can be harnessed to replace the conventional solvents in this highly attractive manifold. Herein, we report that the iron-catalyzed cross-coupling of aryl chlorides and tosylates with challenging organometallics possessing beta-hydrogens that proceed in good to excellent yields using green, sustainable and eco-friendly 2-methyltetrahydrofuran (2-MeTHF)...
March 1, 2018: ChemSusChem
Peter Dragovich, Robert A Blake, Chunjiao Chen, Jinhua Chen, Josefa Chuh, Willem den Besten, Fang Fan, Aimee Fourie, Steven J Hartman, Changrong He, Jintang He, Ellen Rei Ingalla, Katherine R Kozak, Steven R Leong, Jiawei Lu, Yong Ma, Lingyao Meng, Michelle Nannini, Jason Oeh, Rachana Ohri, Gail Lewis Phillips, Thomas H Pillow, Rebecca K Rowntree, Deepak Sampath, Richard Vandlen, Breanna Vollmar, John Wai, Ingrid E Wertz, Keyang Xu, Zijin Xu, Donglu Zhang
A novel strategy to attach indole-containing payloads to antibodies via a carbamate moiety and a self-immolating, disulfide-based linker is described. This new strategy was employed to connect a selective estrogen receptor down-regulator (SERD) to various antibodies in a site-selective manner. The resulting conjugates displayed potent, antigen-dependent down-regulation of estrogen receptor levels in MCF7-neo/HER2 and MCF7-hB7H4 cells. They also exhibited similar antigen-dependent modulation of the estrogen receptor in tumors when administered intravenously to mice bearing MCF7-neo/HER2 tumor xenografts...
February 28, 2018: Chemistry: a European Journal
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