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https://www.readbyqxmd.com/read/28434062/nlophoric-3-6-di-substituted-quinoxalin-carbazoles-synthesis-photophysical-properties-and-dft-studies
#1
Rahul D Telore, Amol G Jadhav, Nagaiyan Sekar
Synthesis of novel 3,6-di(substituted quinoxalin) carbazole fluorophores by the condensation of 1,1'-(9-ethyl-9H-carbazole-3,6-diyl)bis(2-bromoethanone) with methyl, chloro and unsubstituted o-phenylenediamine is presented. Synthesized derivatives are well characterized by (1)H NMR, (13)C NMR, FTIR and Mass spectroscopy. Photophysical studies are carried out using solvents of varying polarities revealed positive solvatochromism and intramolecular charge transfer from carbazole (Donor) to quinoxalin (Acceptor)...
April 22, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28433832/the-theoretical-study-of-excited-state-intramolecular-proton-transfer-of-2-5-bis-benzoxazol-2-yl-thiophene-3-4-diol
#2
Rui-Fang Lan, Yun-Fan Yang, Yan-Zhen Ma, Yong-Qing Li
The symmetrical structures 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol (BBTD) can take shape two intramolecular hydrogen bonds in chloroform. In order to research the molecular dynamic behavior of BBTD upon photo-induced process, we utilize density functional theory (DFT) and time-dependent density functional theory (TDDFT) to complete theoretical calculation. Through the comparison of bond length, bond angle, IR spectra, and frontier molecular orbitals between ground state (S0) and first excited state (S1), it clearly indicates that photoexcitation have slightly influence for intensity of hydrogen bond...
April 18, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28433823/simultaneous-monitoring-of-intra-and-extracellular-nitric-oxide-in-living-cells-by-means-of-dual-color-fluorescence-imaging
#3
Hui-Wen Yao, Jian-Bo Chen, Xiao-Feng Guo, Hong Wang
A dual-color fluorescence imaging method for simultaneous monitoring of intra- and extracellular nitric oxide (NO) was developed. Assisted by confocal laser scanning microscope, the intra- and extracellular NO can be successfully visualized by using two selected probes, 4,4-difluoro-8-(3,4-diaminophenyl)-3,5-bis(4-methoxyphenyl)-4-bora-3a,4a-diaza-s-indacene (p-MOPB) and disodium 2,6-disulfonate-1,3-dimethyl-5-hexadecyl-8-(3,4-diaminophenyl)-4,4'-difluoro-4-bora-3a,4a-diaza-s-indacene (DSDMHDAB), which display distinct membrane permeability and show different colors of fluorescence after reaction with NO...
April 19, 2017: Nitric Oxide: Biology and Chemistry
https://www.readbyqxmd.com/read/28433680/organocatalyzed-and-mechanochemical-solvent-free-synthesis-of-novel-and-functionalized-bis-biphenyl-substituted-thiazolidinones-as-potent-tyrosinase-inhibitors-sar-and-molecular-modeling-studies
#4
Sadaf Mutahir, Muhammad Asim Khan, Islam Ullah Khan, Muhammad Yar, Muhammad Ashraf, Sidra Tariq, Ren-Long Ye, Bao-Jing Zhou
Eluding the involvement of solvents in organic synthesis and introducing environment friendly procedures can control environmental problems. A facile and an efficient solvent free mechanochemical method (grinding) is achieved to synthesize novel bis-biphenyl substituted thiazolidinones using non-toxic and cheap N-acetyl glycine (NAG). Organocatalytic condensation of a series of Schiff's bases bearing different substituents with thioglycolic acid produces a variety of thiazolidinones derivatives in good to excellent yield...
April 13, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28432725/synthesis-and-biological-potency-of-anilino-triazine-insecticides
#5
Timothy C Johnson, Annette V Brown, Kristy K Bryan, Katherine K Guenthenspberger, Ricky Hunter, Timothy P Martin, Noormohamed Niyaz, Gene F Tisdell, Tony Trullinger
BACKGROUND: An insecticide screening effort identified N-(4-bromophenyl)-4,6-bis(2,2,2-trifluoroethoxy)-1,3,5-triazine-2-amine as having weak potency against two Lepidopteran species, Helicoverpa zea and Spodoptera exigua. A structure activity relationship study about the trifluoroethoxy substituents and the aniline of this compound was carried out in an effort to improve insecticidal potency. RESULTS: Initially, a series of analogs bearing various substituents on the aniline were prepared and the insecticidal potency was evaluated against Helicoverpa zea and Spodoptera exigua in greenhouse diet feeding assays...
April 22, 2017: Pest Management Science
https://www.readbyqxmd.com/read/28432000/determination-of-thiol-to-protein-ratio-and-drug-to-antibody-ratio-by-in-line-size-exclusion-chromatography-with-post-column-reaction
#6
Kenichiro Furuki, Toshimasa Toyo'oka
An in-line size-exclusion (SE) ultra-high-performance liquid chromatography (UHPLC)- 5,5-dithio-bis-(2-nitrobenzoic acid) (DTNB) method to quantify thiols in monoclonal antibodies (mAb) when manufacturing antibody-drug conjugates (ADCs) was developed. The mAbs are separated on an SE-UHPLC column and monitored with a UV detector at a wavelength of 280 nm. Eluents are channeled into a reaction coil and mixed with DTNB to form 5-thio-2-nitrobenzoic acid (TNB). Thiol concentration is calculated using absorption at 412 nm...
April 18, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28431519/semi-automatic-synthesis-and-biodistribution-of-n-2-18-f-fluoropropionyl-bis-zinc-ii-dipicolylamine-18-f-fp-dpazn2-for-ad-model-imaging
#7
Fuhua Wen, Dahong Nie, Kongzhen Hu, Ganghua Tang, Shaobo Yao, Caihua Tang
BACKGROUND: Phosphatidylserine (PS)-targeting positron emission tomography (PET) imaging with labeled small-molecule tracer is a crucial non-invasive molecule imaging method of apoptosis. In this study, semi-automatic radiosynthesis and biodistribution of N-(2-(18)F-fluoropropionyl)-bis(zinc(II)-dipicolylamine) ((18)F-FP-DPAZn2), as a potential small-molecule tracer for PET imaging of cell death in Alzheimer's disease (AD) model, were performed. METHODS: (18)F-FP-DPAZn2 was synthesized on the modified PET-MF-2V-IT-I synthesizer...
April 21, 2017: BMC Medical Imaging
https://www.readbyqxmd.com/read/28429811/synthesis-and-structural-characterisation-of-the-aggregates-of-benzo-1-2-chalcogenazole-2-oxides
#8
Peter C Ho, Jamal Rafique, Jiwon Lee, Lucia M Lee, Hilary A Jenkins, James F Britten, Antonio L Braga, Ignacio Vargas-Baca
Iodine oxidation of bis[2-(hydroxyiminomethyl)phenyl] dichalcogenides yields benzo-1,2-chalcogenazole 2-oxides. Annulated derivatives of iso-tellurazole N-oxides spontaneously aggregate into cyclic tetra- and hexamers through TeO chalcogen bonding; the structures of the co-crystals with benzene and CH2Cl2 illustrate the ability of these macrocycles to interact with small guest molecules. The selenium congener crystallizes forming a supramolecular polymer. VT NMR indicates that both compounds aggregate in solution but only at low temperature in the selenium case...
April 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28429421/a-boat-shaped-tetracationic-macrocycle-with-a-semiconducting-organic-framework
#9
Minh T Nguyen, Matthew D Krzyaniak, Magdalena Owczarek, Daniel P Ferris, Michael R Wasielewski, J Fraser Stoddart
We report the synthesis of a tetracationic macrocycle which contains two N,N'-bis(methylene)naphthalenediimide units inserted in between the pyridinium rings of the bipyridinium units in cyclobis(paraquat-p-phenylene) (CBPQT(4+) or "blue box") and describe the investigation of its potential use in materials for organic electronics. The incorporation of the two naphthalenediimide (NDI) units into the constitution of CBPQT(4+) , not only changes the supramolecular properties of the tetracation in the solid state, but also has a profound influence on the electrochemical and electronic behavior of the resulting tetracationic macrocycle...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28429384/enantioselective-silver-and-amine-co-catalyzed-desymmetrizing-cycloisomerization-of-alkyne-linked-cyclohexanones
#10
Rubén Manzano, Swarup Datta, Robert S Paton, Darren J Dixon
A silver(I) and amine co-catalyzed desymmetrization of 4-propargylamino cyclohexanones for the direct enantioselective synthesis of 2-azabicyclo[3.3.1]nonanes is described. Exploiting reactivity arising from dual activation of the pendant terminal alkyne by silver(I) and the ketone moiety through transient enamine formation, this synthetically relevant transformation is easy to perform, efficient and broad in scope. High enantioselectivity (up to 96 % ee) was achieved by exploiting a significant matching effect between the chirality of a cinchona alkaloid-derived aminophosphine ligand for the silver(I) salt and the 2-bis(aryl)methylpyrrolidine catalyst which was rationalized by DFT calculations...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28428977/19th-workshop-of-the-international-stroke-genetics-consortium-april-28-29-2016-boston-massachusetts-usa-2016-001-mri-defined-cerebrovascular-genomics-the-charge-consortium
#11
S Debette, Y Saba, D Vojinovic, X Jian, H Adams, G Chauhan, M Sargurupremraj, S Kaffashian, J Ding, J C Bis, P Nyquist, K Mather, C Van Duijn, L J Launer, M A Ikram, H Schmidt, W T Longstreth, M Fornage, S Seshadri
The CHARGE consortium is an investigator-initiated collaboration to facilitate meta-analyses of genome-wide association studies (GWAS) and genomic analyses based on next generation sequencing (NGS), among multiple large and well-phenotyped population-based cohort studies around the world (http://www.chargeconsortium.com). Within the neuro-CHARGE working group, we are presenting an update of ongoing genomic studies on MRI-markers of cerebrovascular disease. Large population-based studies have shown that the burden of cerebrovascular disease extends far beyond that of clinical stroke...
March 2017: Neurology. Genetics
https://www.readbyqxmd.com/read/28428825/comprehensive-evaluation-of-genome-wide-5-hydroxymethylcytosine-profiling-approaches-in-human-dna
#12
Ksenia Skvortsova, Elena Zotenko, Phuc-Loi Luu, Cathryn M Gould, Shalima S Nair, Susan J Clark, Clare Stirzaker
BACKGROUND: The discovery that 5-methylcytosine (5mC) can be oxidized to 5-hydroxymethylcytosine (5hmC) by the ten-eleven translocation (TET) proteins has prompted wide interest in the potential role of 5hmC in reshaping the mammalian DNA methylation landscape. The gold-standard bisulphite conversion technologies to study DNA methylation do not distinguish between 5mC and 5hmC. However, new approaches to mapping 5hmC genome-wide have advanced rapidly, although it is unclear how the different methods compare in accurately calling 5hmC...
2017: Epigenetics & Chromatin
https://www.readbyqxmd.com/read/28427668/synthesis-of-hydroxyapatite-nanorods-for-application-in-water-defluoridation-and-optimization-of-process-variables-advantage-of-ultrasonication-with-precipitation-method-over-conventional-method
#13
Dhiraj Mehta, Poonam Mondal, Virendra Kumar Saharan, Suja George
This research work presents the synthesis of hydroxyapatite (Hap) nanorods for defluoridation of drinking water by using both conventional (CM) and ultrasonication with precipitation (USPM) methods. Calcium nitrate was reacted with potassium phosphate in presence of ammonia for controlled pH to synthesize Hap nanorods, which was characterized using FTIR, XRD, SEM, TG-DTA, and TEM/EDS for determining its phase composition, structural and thermal decomposition behavior. When USPM method was used for synthesis, the yield of the Hap nanorods was improved from 83...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427651/ultrasonic-synthesis-of-two-nanostructured-cadmium-ii-coordination-supramolecular-polymers-solvent-influence-luminescence-and-photocatalytic-properties
#14
Shao Yun Hao, Xue Gang Ma, Guang Hua Cui
Two nanoparticles of cadmium(II) coordination polymers (CPs) formulated as [Cd(L)(DCTP)]n (1) and [Cd(L)2(DCTP)·2H2O]n (2) (L=1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H2DCTP=2,5-dichloroterephthalic acid) were prepared by the sonochemical approach in different solvents and characterized by elemental analysis, IR spectra, scanning electron microscopy (SEM), and powder X-ray diffraction. Structural determination reveals that CP 1 displays a 2D four-connected sql net layer, Whilst CP 2 exhibits a 1D "V"-like chain structure...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427636/ultrasound-assisted-synthesis-of-nano-structured-zinc-ii-based-metal-organic-frameworks-as-precursors-for-the-synthesis-of-zno-nano-structures
#15
Fahime Bigdeli, Hosein Ghasempour, Alireza Azhdari Tehrani, Ali Morsali, Hassan Hosseini-Monfared
A 3D, porous Zn(II)-based metal-organic framework {[Zn2(oba)2(4-bpmn)]·(DMF)1.5}n (TMU-21), (4-bpmn=N,N'-Bis-pyridin-4-ylmethylene-naphtalene-1,5-diamine, H2oba=4,4'-oxybis(benzoic acid)) with nano-rods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure was prepared and characterized by scanning electron microscopy. Sonication time and concentration of initial reagents effects on the size and morphology of nano-structured MOFs were studied. Also {[Zn2(oba)2(4-bpmn)] (TMU-21) and {[Zn2(oba)2(4-bpmb)] (TMU-6), 4-bpmb=N,N'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) were easily prepared by mechanochemical synthesis...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427259/copper-catalyzed-diaryl-ether-formation-from-hetero-aryl-halides-at-low-catalytic-loadings
#16
Yuntong Zhai, Xiaofei Chen, Wei Zhou, Mengyang Fan, Yisheng Lai, Dawei Ma
Diaryl formation is achieved by coupling phenols and (hetero)aryl halides under the catalysis of CuI/N,N'-bis(2-phenylphenyl) oxalamide (BPPO) or CuI/ N-(2-phenylphenyl)-N'-benzyl oxalamide (PPBO) at 90 degrees C using DMF or MeCN as the solvent. Only 0.2-2 mol % CuI and ligand are required for completer conversion, which represents the lowest catalytic loadings for a general Cu/ligand-catalyzed diaryl ether formation.
April 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28426997/design-and-synthesis-of-neolamellarin-a-derivatives-targeting-heat-shock-protein-90
#17
Long Jiang, Ruijuan Yin, Xueting Wang, Jiajia Dai, Jing Li, Tao Jiang, Rilei Yu
In this study, we designed and synthesized a novel family of neolamellarin A derivatives that showed high inhibitory activity toward heat shock protein 90 (Hsp90), a kinase associated with cell proliferation. The 3,4-bis(catechol)pyrrole scaffold and the benzyl group with methoxy modification at N position of pyrrole are essential to the Hsp90 inhibitory activity and cytotoxicity of these compounds. Western blot analysis demonstrated that these compounds induced dramatic depletion of the examined client proteins of Hsp90, and accelerated cancer cell apoptosis...
April 15, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28426875/bisphenol-a-activates-egfr-and-erk-promoting-proliferation-tumor-spheroid-formation-and-resistance-to-egfr-pathway-inhibition-in-estrogen-receptor-negative-inflammatory-breast-cancer-cells
#18
Scott J Sauer, Michael Tarpley, Imran Shah, Akshay V Save, H Kim Lyerly, Steven R Patierno, Kevin P Williams, Gayathri R Devi
Emerging evidence from epidemiological studies suggests a link between environmental chemical exposure and progression of aggressive breast cancer subtypes. Of all clinically distinct types of breast cancers, the most lethal phenotypic variant is inflammatory breast cancer (IBC). Overexpression of epidermal growth factor receptors (EGFR/HER2) along with estrogen receptor (ER) negativity is common in IBC tumor cells, which instead of a solid mass present as rapidly proliferating diffuse tumor cell clusters. Our previous studies have demonstrated a role of an adaptive response of increased antioxidants in acquired resistance to EGFR-targeting drugs in IBC...
March 1, 2017: Carcinogenesis
https://www.readbyqxmd.com/read/28426230/photophysics-and-excited-state-properties-of-cyclometalated-iridium-iii-platinum-ii-and-iridium-iii-iridium-iii-bimetallic-complexes-bridged-by-dipyridylpyrazine
#19
Yang-Jin Cho, So-Yoen Kim, Chang Min Choi, Nam Joon Kim, Chul Hoon Kim, Dae Won Cho, Ho-Jin Son, Chyongjin Pac, Sang Ook Kang
We investigated the electrochemical and excited-state properties of 2,3-bis(2-pyridyl)pyrazine (dpp)-bridged bimetallic complexes, (L)2Ir-dpp-PtCl [1, L = 2-(4',6'-difluorophenyl)pyridinato-N,C(2) (dfppy); 2, L = 2-phenylpyridinato-N,C(2) (ppy)] and [(L)2Ir]2(dpp) [3, L = dfppy; 4, L = ppy] compared to monometallic complexes, (L)2Ir-dpp (5, L = dfppy; 6, L = ppy) and dpp-PtCl (dpp-Pt(II)Cl2; 7). The single-crystal X-ray crystallographic structures of 1, 3, 5, and 6 showed that 1 and 3 have approximately coplanar structures of the dpp unit, while the noncoordinated pyridine ring of dpp in 5 and 6 is largely twisted with respect to the pyrazine ring...
April 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28426220/fluorescent-neuraminidase-assay-based-on-supramolecular-dye-capture-after-enzymatic-cleavage
#20
Wenqi Liu, César F A Gómez-Durán, Bradley D Smith
A conceptually new type of enzymatic cleavage assay is reported that utilizes in-situ supramolecular capture of the fluorescent product. A squaraine-derived substrate with large blocking groups at each end of its structure cannot be threaded by a tetralactam macrocycle until the blocking groups are removed by enzyme cleavage. A prototype design responds to viral neuraminidase, an indicator of influenza infection, and also measures susceptibility of the sample to neuraminidase inhibitor drugs. The substrate structure incorporates three key features; (a) a bis(4-amino-3-hydroxyphenyl)squaraine core with bright deep-red fluorescence and excellent photostability, (b) an N-methyl group at each end of the squaraine core that ensures fast macrocycle threading kinetics, and (c) sialic acid blocking groups that prevent macrocycle threading until they are removed by viral neuraminidase...
April 20, 2017: Journal of the American Chemical Society
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