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https://www.readbyqxmd.com/read/28549345/a-novel-synthetic-derivative-of-quercetin-8-trifluoromethyl-3-5-7-3-4-o-pentamethyl-quercetin-inhibits-bladder-cancer-growth-by-targeting-the-ampk-mtor-signaling-pathway
#1
Ting Tao, Caimei He, Jun Deng, Yanjun Huang, Qiongli Su, Mei Peng, Meiling Yi, Kwame Oteng Darko, Hui Zou, Xiaoping Yang
Quercetin is a naturally existing compound and shows attractive anticancer properties for a variety of solid tumors including glioma, bladder cancer, hepatocellular carcinoma, breast cancer, hematological malignancies and prostate carcinoma. However, these anticancer properties have not been clinically approved due to unclear mechanistic information and its low bioactivity. In our previous study, we elucidated that quercetin activates AMPK pathway which is the major mechanism for its unique anticancer effect in bladder cancer...
May 11, 2017: Oncotarget
https://www.readbyqxmd.com/read/28548849/de-risking-the-cu-mediated-18f-fluorination-of-heterocyclic-pet-radioligands
#2
Nicholas Taylor, Enrico Emer, Sean Preshlock, Michael Schedler, Matthew Tredwell, Stefan Verhoog, Joël Mercier, Christophe Genicot, Veronique Emilie Gouverneur
Molecules labeled with fluorine 18 (18F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a de-risking approach towards the radiosynthesis of heterocyclic PET radioligands using the copper-mediated 18F fluorination of aryl boron reagents with 18F-fluoride as a model reaction...
May 26, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28548848/quantum-mechanical-study-of-the-reaction-mechanism-for-2%C3%AF-2%C3%AF-cycloaddition-of-fluorinated-methylene-groups
#3
Andrew R Motz, Andrew M Herring, Shubham Vyas, C Mark Maupin
Perfluorocyclobutyl polymers are thermally and chemically stable, may be produced without a catalyst via thermal 2π-2π cycloaddition, and can form block structures making them suitable for commercialization of specialty polymers. Thermal 2π-2π cycloaddition is a rare reaction that starts in the singlet state and proceeds through a triplet intermediate forming an energetically stable 4 membered ring in the singlet state. This reaction involves two changes in spin state and thus two spin-crossover transitions...
May 26, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28548837/the-role-of-the-hydroxyl-group-in-propofol-protein-target-recognition-insights-from-oniom-studies
#4
Ling Qiu, Jianguo Lin, Qingzhu Liu, Shanshan Wang, Gaochao Lv, Ke Li, Haiming Shi, Zhengkun Huang, Edward J Bertaccini
Propofol (PFL, 1-hydroxyl-2,6-diisopropylbenzene) is currently used widely as one of the most well-known intravenous anesthetics to relieve surgical suffering, but its mechanism of action is not yet clear. Previous experimental studies have demonstrated that the hydroxyl group of PFL plays a dominant role in the molecular recognition of PFL with receptors that lead to hypnosis. To further explore the mechanism of anesthesia induced by PFL in the present work, the exact binding features and interaction details of PFL with three important proteins, human serum albumin (HSA), the pH-gated ion channel from Gloeobacter violaceus (GLIC) and horse spleen apoferritin (HSAF), were investigated systematically by using a rigorous three-layer ONIOM(M06-2X/6-31+G*:PM6:AMBER) method...
May 26, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28547007/rapid-self-healing-and-anion-selectivity-in-metallosupramolecular-gels-assisted-by-fluorine-fluorine-interactions
#5
Leticia Arnedo-Sánchez, Nonappa, Sandip Bhowmik, Sami Hietala, Rakesh Puttreddy, Manu Lahtinen, Luisa De Cola, Kari Rissanen
Simple ML2 [M = Fe(ii), Co(ii), Ni(ii)] complexes obtained from a perfluoroalkylamide derivative of 4-aminophenyl-2,2',6,2'-terpyridine spontaneously, yet anion selectively, self-assemble into gels, which manifest an unprecedented rapid gel strength recovery, viz. self-healing, and thermal rearrangement in aqueous dimethyl sulfoxide. The key factor for gelation and rheological properties emerges from the fluorine-fluorine interactions between the perfluorinated chains, as the corresponding hydrocarbon derivative did not form metallogels...
May 26, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28546844/molecular-level-architectural-design-using-benzothiadiazole-based-polymers-for-photovoltaic-applications
#6
Vinila N Viswanathan, Arun D Rao, Upendra K Pandey, Arul Varman Kesavan, Praveen C Ramamurthy
A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at -5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28546645/fluorination-at-the-4-position-alters-the-substrate-behavior-of-l-glutamine-and-l-glutamate-implications-for-positron-emission-tomography-of-neoplasias
#7
Thomas M Jeitner, Eva Kristoferson, Juan A Azcona, John T Pinto, Clint Stalnecker, Jon W Erickson, Hank F Kung, Jianyong Li, Karl Ploessl, Arthur J L Cooper
Two 4-fluoro-L-glutamine diastereoisomers [(2S,4R)-4-FGln, (2S,4S)-4-FGln] were previously developed for positron emission tomography. Label uptake into two tumor cell types was greater with [(18)F](2S,4R)-4-FGln than with [(18)F](2S,4S)-4-FGln. In the present work we investigated the enzymology of two diastereoisomers of 4-FGln, two diastereoisomers of 4-fluoroglutamate (4-FGlu) (potential metabolites of the 4-FGln diastereoisomers) and another fluoro-derivative of L-glutamine [(2S,4S)-4-(3-fluoropropyl)glutamine (FP-Gln)]...
December 2016: Journal of Fluorine Chemistry
https://www.readbyqxmd.com/read/28545297/polymer-chromophore-catalyst-assembly-for-solar-fuel-generation
#8
Junlin Jiang, Benjamin D Sherman, Yan Zhao, Ru He, Ion Ghiviriga, Leila Alibabaei, Thomas J Meyer, Gyu Leem, Kirk S Schanze
A polystyrene-based chromophore-catalyst assembly (poly-2) has been synthesized and assembled at a mesoporous metal oxide photoanode. The assembly contains water oxidation catalyst centers based on [Ru(trpy)(phenq)(2+)] (Ru-Cat) and a [Ru(bpy)3](2+) derivative (Ru-C) as chromophores (trpy= 2,2';6,2″- terpyridine, phenq = 2-(quinol-8'-yl)-1,10-phenanthroline and bpy = 2,2'-bipyridine). The photophysical and electrochemical properties of the polychromophore-oxidation catalyst assembly were investigated in solution and at the surface of mesoporous metal oxide films...
May 26, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28544981/synthesis-and-in%C3%A2-vitro-evaluation-of-new-fluorinated-quinoline-derivatives-with-high-affinity-for-pde5-towards-the-development-of-new-pet-neuroimaging-probes
#9
Jianrong Liu, Aurélie Maisonial-Besset, Barbara Wenzel, Damien Canitrot, Ariane Baufond, Jean-Michel Chezal, Peter Brust, Emmanuel Moreau
The increasing incidence of Alzheimer's disease (AD) worldwide is a major public health problem. Current treatments provide only palliative solutions with significant side effects. Therefore, new efficient treatment options and novel early diagnosis tools are urgently needed. Recently, strong pre-clinical evidences suggested that phosphodiesterase 5 (PDE5) may be clinically relevant both as biomarker and drug-target in AD. In this study, we intended to develop a new radiofluorinated tracer for the visualisation of PDE5 in brain using PET imaging...
April 19, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28544560/fatal-intoxication-by-5f-adb-and-diphenidine-detection-quantification-and-investigation-of-their-main-metabolic-pathways-in-human-by-lc-ms-ms-and-lc-q-tofms
#10
Maiko Kusano, Kei Zaitsua, Kentaro Taki, Kazuaki Hisatsune, Jun'ichi Nakajima, Takako Moriyasu, Tomomi Asano, Yumi Hayashi, Hitoshi Tsuchihashi, Akira Ishii
Despite the implementation of the new blanket scheduling system in 2013, new psychoactive substance (NPS) abuse remains a serious social concern in Japan. We present a fatal intoxication case involving 5F-ADB (methyl 2-[1-(5-fluoropentyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate) and diphenidine. Postmortem blood screening by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOFMS) in the information dependent acquisition (IDA) mode only detected diphenidine. Further urinary screening using an in-house database containing new NPS and metabolites detected not only diphenidine but also possible 5F-ADB metabolites; subsequent targeted screening by LC/tandem mass spectrometry (LC/MS/MS) allowed for the detection of very low level of unchanged 5F-ADB in postmortem heart blood...
May 21, 2017: Drug Testing and Analysis
https://www.readbyqxmd.com/read/28544216/a-structurally-characterized-fluoroalkyne
#11
Lewis M Hall, David P Tew, Natalie E Pridmore, Adrian C Whitwood, Jason M Lynam, John M Slattery
The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M-C≡CF, is reported. Reaction of [Ru(C≡CH)(η(5) -C5 Me5 )(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η(5) -C5 Me5 )(dppe)][N(SO2 Ph)2 ]. Subsequent deprotonation with LiN(SiMe3 )2 affords the fluoroalkynyl complex [Ru(C≡CF)(η(5) -C5 Me5 )(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized...
May 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544160/a-unified-continuous-flow-assembly-line-synthesis-of-highly-substituted-pyrazoles-and-pyrazolines
#12
Joshua Britton, Timothy F Jamison
A rapid and modular continuous flow synthesis of highly functionalized fluorinated pyrazoles and pyrazolines has been developed. Flowing fluorinated amines through sequential reactor coils mediates diazoalkane formation and [3+2] cycloaddition to generate more than 30 azoles in a telescoped fashion. Pyrazole cores are then sequentially modified through additional reactor modules performing N-alkylation and arylation, deprotection, and amidation to install broad molecular diversity in short order. Continuous flow synthesis enables the safe handling of diazoalkanes at elevated temperatures, and the use of aryl alkyne dipolarphiles under catalyst free conditions...
May 25, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28543628/tunable-wettability-of-electrospun-polyurethane-silica-composite-membranes-for-effective-separation-of-water-in-oil-and-oil-in-water-emulsions
#13
Libin Liu, Wenyuan Fang, Gailan Guo
Polymer-dominated membranes with switchable wettability are highly desired due to their on-demand applications for oil/water separation. Herein, we report a low-cost methodology to fabricate membranes consisting of hyperbranched polyurethane (HBPU) and fluorine-modified silica (F-SiO2) with tunable wettability by electrospinning. The HBPU/F-SiO2 composite membranes can be transformed from superhydrophobicity to superhydrophilicity via plasma treatment, which exhibit different wettability for effective separation of surfactant-stabilized water-in-oil and oil-in-water emulsions...
May 24, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28541682/powerful-thermally-stable-one-pot-preparable-and-recyclable-electrophilic-trifluoromethylating-agents-2-8-difluoro-and-2-3-7-8-tetrafluoro-s-trifluoromethyl-dibenzothiophenium-salts
#14
Teruo Umemoto, Bin Zhang, Tianhao Zhu, Xiaocong Zhou, Peng Zhang, Song Hu, Yuanqiang Li
Although many electrophilic trifluoromethylating agents have been reported to date, practically useful reagents have yet to be developed. S-(Trifluoromethyl)dibenzothiophenium salts, known as Umemoto's reagents, have two significant drawbacks that have hampered their practical application: (1) synthesis involving many steps and (2) the formation of large amounts of dibenzothiophene as waste after trifluoromethylation. Our idea to substitute fluorine at specific positions on the dibenzothiophenium rings has resulted in massive improvements in the synthesis, properties, reactivity, and applications of these compounds...
May 25, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28541558/drinking-water-contamination-from-perfluoroalkyl-substances-pfas-an-ecological-mortality-study-in-the-veneto-region-italy
#15
Marina Mastrantonio, Edoardo Bai, Raffaella Uccelli, Vincenzo Cordiano, Augusto Screpanti, Paolo Crosignani
: Perfluoroalkyl substances (PFAS), a heterogeneous group of highly stable man-made chemicals, have been widely used since 1960s and can be detected almost ubiquitously in all environmental matrices. In Italy, on January 2014, drinking water contamination in an area of the Veneto Region was detected mainly due to the drain of fluorinated chemicals by a manufacturing company operating since 1964. : The present ecological mortality study was aimed at comparing mortality for some causes of death selected on the basis of previous reported associations, during the period 1980-2013, in municipalities with PFAS contaminated and uncontaminated drinking water on the basis of the levels indicated by the Italian National Health Institute (ISS)...
May 23, 2017: European Journal of Public Health
https://www.readbyqxmd.com/read/28541049/synthesis-and-photophysical-and-photocatalytic-properties-of-a-highly-fluorinated-and-durable-phthalocyanine-peptide-bioconjugate-for-potential-theranostic-applications
#16
Erik N Carrión, Jenyffer Santiago, David Sabatino, Sergiu M Gorun
The functionalized, asymmetric fluoro-fluoroalkyl scaffold F48H7COOHPcZn (3) was used to prepare F48H7COOPcZn-6-amino-hexanoate-CTVALPGGYVRVC (5), a Pep42 peptide bioconjugate envisioned for photodynamic therapy, which can specifically target the GRP78 chaperone protein overexpressed and exclusively localized on some cancer cell surfaces. The analogous F48H7COOHPcCu (4) has also been prepared, and its single-crystal X-ray structure was elucidated. Despite reduced steric hindrance relative to the nonfunctionalized, single-site complexes of the F64Pc scaffold, no aggregation was detected in solution via UV-vis spectroscopy, for either 3, 4, or 5, consistent with the lack of π stacking observed for the crystalline 4...
May 25, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28540739/hypoxia-imaging-and-radiotherapy-bridging-the-resolution-gap
#17
David Robert Grimes, Daniel R Warren, Samantha Warren
Oxygen distribution is a major determinant of treatment success in radiotherapy, with well-oxygenated tumour regions responding by up to a factor of three relative to anoxic volumes. Conversely, tumour hypoxia is associated with treatment resistance and negative prognosis. Tumour oxygenation is highly heterogeneous and difficult to measure directly. The recent advent of functional hypoxia imaging modalities such as fluorine-18 fluoromisonidazole positron emission tomography have shown promise in non-invasively determining regions of low oxygen tension...
May 25, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28539594/toward-a-nearly-defect-free-coating-via-high-energy-plasma-sparks
#18
Mosab Kaseem, Hae Woong Yang, Young Gun Ko
A nearly defect-free metal-oxide-based coating structure was made on Al-Mg-Si alloy by plasma electrolytic oxidation at high current density accompanying high-energy plasma sparks. The present coatings were performed at two different current densities of 50 and 125 mA/cm(2) in the alkaline-phosphate-based electrolytes with different concentrations of sodium hexafluoroaluminate (Na3AlF6). The addition of (Na3AlF6) to the electrolyte used in this study would result in a decrease in the size of the micropore, and a reasonably defect-free coating structure was achieved in the sample treated at high current density of 125 mA/cm(2)...
May 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28537884/a-cancer-vaccine-based-on-fluorine-modified-sialyl-tn-induces-robust-immune-responses-in-a-murine-model
#19
Chengcheng Song, Xiu-Jing Zheng, Chang-Cheng Liu, Yifa Zhou, Xin-Shan Ye
Development of an effective vaccine to target tumor associated carbohydrate antigens, aberrantly expressed on the cell surface of various carcinomas, is an appealing approach toward cancer immunotherapy. However, a major problem of carbohydrate antigens is their poor immunogenicity. Immunization with modified-carbohydrate antigens could improve the immunogenicity and induce cross reaction with the native carbohydrate antigens. In this study, we investigated the antitumor ability of three fluoro-substituted sialyl-Tn (STn) analogues (2, 3, 4) coupled to KLH (keyhole limpet hemocyanin) and studied the mechanism of tumor immunotherapy of the vaccines in a murine model of colon cancer...
May 6, 2017: Oncotarget
https://www.readbyqxmd.com/read/28537705/hypoxia-responsive-19-f-mri-probes-with-improved-redox-properties-and-biocompatibility
#20
Da Xie, Seyong Kim, Vikraant Kohli, Arnab Banerjee, Meng Yu, José S Enriquez, Jeffrey J Luci, Emily L Que
(19)F magnetic resonance imaging (MRI), an emerging modality in biomedical imaging, has shown promise for in vitro and in vivo preclinical studies. Here we present a series of fluorinated Cu(II)ATSM derivatives for potential use as (19)F magnetic resonance agents for sensing cellular hypoxia. The synthesized complexes feature a hypoxia-targeting Cu(2+) coordination core, nine equivalent fluorine atoms connected via a variable-length poly(ethylene glycol) linker. Introduction of the fluorine moiety maintains the planar coordination geometry of the Cu(2+) center, while the linker length modulates the Cu(2+/+) reduction potential, (19)F NMR relaxation properties, and lipophilicity...
May 24, 2017: Inorganic Chemistry
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