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Saulo F Andrade, Bárbara G Oliveira, Larissa C Pereira, Jonas P Ramos, Angélica R Joaquim, Martin Steppe, Elaine M Souza-Fagundes, Ricardo J Alves
In the present work we describe the synthesis and antiproliferative evaluation of a focused library of 30 novel oxazolidines designed by modification of N-substituent, by ring variation, by alkyl variation or by extension of the structure. It was noted that carbamate and N,O-aminal groups were essential for activity. In general, replacement of the phenyl ring with pyridinyl was not tolerated. However, the introduction of a second phenyl ring with an appropriate spacer at the 3- or 4-position of the first phenyl ring generally enhanced the cytotoxic profile...
June 12, 2017: European Journal of Medicinal Chemistry
Mingao Wang, Rujuan Xie, Xibei Jia, Ruichan Liu
OBJECTIVE: To detect urinary volatile organic compounds (VOCs) in patients with idiopathic membranous nephropathy (iMN) and normal controls, and whether or not the urinary VOCs can act as biomarkers for diagnosis of iMN independent of renal biopsy. MATERIALS AND METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to assess the urine collected from 63 iMN patients and 15 normal controls. The statistical methods of principal component analysis (PCA) and partial least squares discriminant analysis (PLSDA) were performed to process the final data in CDF format which were converted from GC/MS data...
June 19, 2017: Medical Principles and Practice: International Journal of the Kuwait University, Health Science Centre
Anh Tran, Jin-Quan Yu
The development of new and practical 3-pentoxythiocarbonyl auxiliaries for Ir(I)-catalyzed CH alkylation of azacycles is described. This method allows for the -CH alkylation of a variety of substituted pyrrolidines, piperidine and tetrahydroisoquinoline through alkylation with alkenes. While the practicality of these simiple carbamate type auxiliaries is underscored in the ease of installation and removal, the method's novel reactivity is demonstrated in its ability to functionalize biologically relevant (L)-proline and (L)-trans-hydroxyproline, delivering unique 2,5-dialkylated amino acid analogues that are not accessible by other C-H functionalization methods...
June 16, 2017: Angewandte Chemie
Minsoo Ju, Cale Weatherly, Ilia Guzei, Jennifer M Schomaker
Asymmetric nitrene transfer reactions are a powerful tool for the preparation of enantioenriched amine building blocks. Herein, we report chemo- and enantioselective silver-catalyzed aminations that transform di- and trisubstituted homoallylic carbamates into [4.1.0]-carbamate-tethered aziridines in good yields and ee up to 92%. The effects of the substrate, silver counteranion, ligand, solvent and temperature on both chemoselectivity and ee were explored to complement the scope of traditional metal-catalyzed nitrene transfer reactions...
June 14, 2017: Angewandte Chemie
Saki Matsumoto, Kei Iida, Asako Murata, Masatsugu Denawa, Masatoshi Hagiwara, Kazuhiko Nakatani
A naphthyridine carbamate tetramer (NCT8) is a synthetic compound, which selectively binds to nucleic acids containing CGG/CGG sequence. Although NCT8 is a promising compound for a wide range of DNA and RNA based biotechnology such as modulation of specific gene expression, little is known about its behavior in human cells. In the present study, we investigated the changes induced in gene expression by NCT8. Genes differentially expressed in the presence of NCT8 in HeLa cells were identified by whole-transcriptome analysis...
June 3, 2017: Bioorganic & Medicinal Chemistry Letters
Xiang Wang, Barbara Wicher, Yann Ferrand, Ivan Huc
An aromatic oligoamide sequence was designed to fold and self-assemble into a double helical host having a cylindrical cavity complementary to linear oligo-carbamates guests. Formation of helical pseudo-rotaxane complexes - foldaxanes - between the host and guests having binding stations of different affinities was evidenced by NMR and x-ray crystallog-raphy. Rod-like guests possessing two or three binding stations, long alkyl or oligoethylene glycol spacers or bulky barriers in-between the binding stations, and a single bulky stopper at one end, were synthesized...
June 13, 2017: Journal of the American Chemical Society
Imran Ali, Mohd Suhail, Zeid A Alothman, Abdulrahman Alwarthan
Chiral resolution of baclofen, bupropion, and etodolac profens was obtained with amylose derivatized chiral reversed stationary phase (carbamate groups). The eluent used for bupropion and etodolac was MeOH-water (20:80, v/v) and for baclofen was water-methanol (95:5, v/v). The eluent run rates, finding wavelength and temperature, were 1.0 mL/min, 220 nm and 27 ± 1 °C for all the eluents. The magnitude of the retardation factors for S- and R-enantiomers of baclofen, bupropion, and etodolac were 1.37, 2...
July 2017: Chirality
Max Fotakis, Alexandra Chaskopoulou, Linda Grigoraki, Alexandros Tsiamantas, Stella Kounadi, Loukas Georgiou, John Vontas
Greece has been recently affected by several mosquito borne diseases with the West Nile Virus (WNV) outbreak in 2010 being one of the largest reported in Europe. Currently at the epicenter of an economic and refugee crisis and visited by over 16 million tourists a year the integrated management of diseases transmitted by mosquitoes is a public health and economic priority. Vector control programs rely mainly on insecticides, however data on insecticide resistance and the mosquito fauna is essential for successful applications...
June 9, 2017: Acta Tropica
Carolin Menzel, Gulaim Seisenbaeva, Peter Agback, Mikael Gällstedt, Antal Boldizar, Kristine Koch
Wheat starch carbamates of different degrees of substitution were produced in laboratory experiments and for the first time their film forming performance were investigated. The carbamation reaction between urea and starch was investigated using a factorial design. Long reaction time, 2h, and high urea content, 10 and 25%, resulted in a high degree of substitution, 0.07 and 0.15, respectively. These starch carbamates were assumed to be cross-linked and showed best film forming properties resulting in continuous and firm films...
September 15, 2017: Carbohydrate Polymers
Sinyee Gan, Sarani Zakaria, Sharifah Nabihah Syed Jaafar
Cellulose carbamate (CC) was synthesized via hydrothermal process and mixed with graphene oxide (GO) to form a homogeneous cellulose matrix nanocomposite films. The properties of CC/GO nanocomposite films fabricated using simple solution-mixing method with different GO loadings were studied. Transmission electron microscope analysis showed the exfoliation of self-synthesized GO nanosheets within the CC matrix. X-ray diffraction results confirmed the crystalline structure of CC/GO films as the CC/GO mass ratio increased from 100/0 to 100/4...
September 15, 2017: Carbohydrate Polymers
Joseph A Ioppolo, Deanna Caldwell, Omid Beiraghi, Lisset Llano, Megan Blacker, John F Valliant, Paul J Berti
INTRODUCTION: Deferoxamine (DFO) is a siderophore that bacteria use to scavenge iron and could serve as a targeting vector to image bacterial infection where current techniques have critical limitations. [(67)Ga]-DFO, which is a mimetic of the corresponding iron complex, is taken up by bacteria in culture, however in vivo it clears too rapidly to allow for imaging of infection. In response, we developed several new DFO derivatives to identify those that accumulate in bacteria, and at sites of infection, and that could potentially have improved pharmacokinetics...
June 1, 2017: Nuclear Medicine and Biology
Kenneth Dahl, Thomas L Collier, Ran Chang, Xiaofei Zhang, Oleg Sadovski, Steven H Liang, Neil Vasdev
Carbon-11 labelled carbon dioxide is the most common feedstock for the synthesis of positron emission tomography radiotracers, and can be directly used for (11) C-carbonylation. Herein, we report the development of an apparatus that takes advantage of "in-loop" technologies to facilitate robust and reproducible syntheses of (11) C-carbonyl-based radiotracers by [(11) C]CO2 -fixation. Our "in-loop" [(11) C]CO2 -fixation method is simple, efficient, and proceeds smoothly at ambient pressure and temperature. We selected model (11) C-carbonyl labelled carbamates as well as symmetrical and unsymmetrical ureas based on their widespread use in radiotracer design and our clinical research interests for proof-of-concept...
June 9, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Xingyu Jiang, John F Hartwig
Enantioselective allylic substitutions with enolates derived from aliphatic esters under mild conditions remain challenging. Herein we report iridium-catalyzed enantioselective allylations of silyl ketene acetals, the silicon enolates of esters, to form products containing a quaternary carbon at the nucleophile moiety and a tertiary carbon at the electrophile moiety. Under relatively neutral conditions, the allylated aliphatic esters were obtained with excellent regioselectivity and enantioselectivity. These products were readily converted to primary alcohols, carboxylic acids, amides, isocyanates, and carbamates, as well as tetrahydrofuran (THF) and γ-butyrolactone derivatives, without erosion of enantiomeric purity...
June 8, 2017: Angewandte Chemie
K M U Janadaree Bandara, S H P Parakrama Karunaratne
High tolerance of ticks to acaricides is increasingly becoming a problem to cattle farmers. Resistance status of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)from two cattle farms of Sri Lanka were determined against different concentrations of pyrethroid permethrin, organophosphate malathion, organochlorine DDT and carbamate propoxur using Larval Packet Test (LPT) as recommended by Food and Agriculture Organization (FAO). Mechanisms of acaricide resistance were studied by conducting biochemical and PCR assays...
June 2017: Pesticide Biochemistry and Physiology
Yoshiki Suzuki, Yoshito Kamijo, Tomohiro Yoshizawa, Yuji Fujita, Kiyotaka Usui, Tohru Kishino
CASE PRESENTATION: A 91-year-old woman was transferred to our Emergency Medical Center and Poison Center with somnolence, hypertension (186/61 mm Hg), and repeated vomiting. Three hours later, 10 transdermal patches, each containing 18 mg of rivastigmine (9.5 mg/24 h), were found on her lower back and both thighs, when miosis, facial and trunk sweating, enhanced bowel sound, hypertension, and sinus tachycardia were noted. She was diagnosed with acute cholinergic syndrome due to rivastigmine poisoning...
June 8, 2017: Clinical Toxicology
Chunghyeon Yu, Mahbubul Alam Shoaib, Naeem Iqbal, Jun Soo Kim, Hyun-Joon Ha, Eun Jin Cho
Our study shows that among aza-heterocycles of various ring sizes, including aziridines, azetidines, pyrrolidines, and piperidines, only N-alkyl pyrrolidines undergo competitive reaction pathways with chloroformates to yield N-dealkylated pyrrolidines and 4-chlorobutyl carbamates. The pathway taken depends on the substituent on the nitrogen, i.e., ring-opening with methyl and ethyl substituents and dealkylation with a benzyl substituent. Computational calculations support the substituent-dependent product formation by showing the energy difference between the transition states of both reaction pathways...
June 15, 2017: Journal of Organic Chemistry
Yuan-Zhong Zhao, Wei-Li Yu, He Zheng, Xuan Guo, Nan Guo, Tao Hu, Jin-Yi Zhong
Haloalkane dehalogenase (HLD) can catalyze the hydrolytic dehalogenation of halogenated compounds. However, HLD suffers from the poor stability to resist the environmental stress. PEGylation is an effective approach to enhance the stability of enzymes. The linker is an important stabilization factor of PEGylation. Thus, the linkers of the PEGylated HLD were optimized to improve the stability of HLD in the present study. The PEGylated haloalkane dehalogenase DhaAs with methylamine (Ml), carbamate (Cm) and thiosuccinimido butylamine (Tb) linkers were prepared, respectively...
June 3, 2017: Journal of Biotechnology
Wei-Guang Shan, Han-Guang Wang, Yan Chen, Rui Wu, Yan-Tao Wen, Li-Wen Zhang, You-Min Ying, Jian-Wei Wang, Zha-Jun Zhan
A series of 3-carbamate and 29-ester celastrol derivatives (compounds 1-26) were designed and synthesized. These analogues were evaluated for their cytotoxic activities against several cancer cell lines. Cytotoxicity data revealed that the properties of substituents and substitution position had important influence on cytotoxic activity. Modification of C-3 hydroxyl with size-limited groups did not reduce the activity obviously. The introduction of polarity group like piperazine could improve the solubility...
May 27, 2017: Bioorganic & Medicinal Chemistry Letters
Mohsen Bahrami, Paul J Laurienti, Sara A Quandt, Jennifer Talton, Carey N Pope, Phillip Summers, Jonathan H Burdette, Haiying Chen, Jing Liu, Timothy D Howard, Thomas A Arcury, Sean L Simpson
Latino immigrants that work on farms experience chronic exposures to potential neurotoxicants, such as pesticides, as part of their work. For tobacco farmworkers there is the additional risk of exposure to moderate to high doses of nicotine. Pesticide and nicotine exposures have been associated with neurological changes in the brain. Long-term exposure to cholinesterase-inhibiting pesticides, such as organophosphates and carbamates, and nicotine place this vulnerable population at risk for developing neurological dysfunction...
June 2, 2017: Neurotoxicology
Joseph Cowell, Matthew Buck, Ali H Essa, Rebecca Clarke, Waldemar Vollmer, Daniela Vollmer, Catharien Hilkens, John Isaacs, Michael J Hall, Joe Gray
Biotinylation of amines is widely used to conjugate biomolecules, but the resulting label is either non-removable or removal leaves a tag on the molecule of interest, affecting downstream processes. We present here a set of reagents (RevAmines) that allow traceless, reversible biotinylation under biologically-compatible, mild conditions. Release following avidin-based capture is achieved through the cleavage of a (2-(alkylsulfonyl)ethyl) carbamate linker under mild conditions (200 mM ammonium bicarbonate, pH 8, 16 - 24 h, r...
June 5, 2017: Chembiochem: a European Journal of Chemical Biology
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