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Joby Jose, A T Dhanya, Karickal R Haridas, T M Sumesh Kumar, Sony Jayaraman, E Jayadevi Variyar, Sudheesh Sudhakaran
The study was initiated to determine the anticancer activity of a novel compound isolated from the plant Mimosa pudica. The structure of the compound was identified as a derivative of myricetin having alkyl, hydroxy alkyl and methyl substitutions on the basis of spectral evidences (UV-vis, FT-IR, (1)H NMR and Mass spectra). The isolated compound was interpreted as 2-(2',6'-dimethyl-3',4',5'-alkyl or hydroxy alkyl substituted phenyl)-3-oxy-(alkyl or hydoxy alkyl)- 5,7-dihydroxy-chromen-4-one. In vitro evaluation of anticancer activity against human lung adenocarcinoma cell line (A549) and human erythroleukemic cell line (K562) were conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay...
October 22, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Mohammad Shakir, Summaiya Hanif, Md Fazle Alam, Hina Younus
Novel bio-relevant monometallic Schiff base complexes of the type, [Cu(L(1))2] (1), [Zn(L(1))2]·2H2O (2), [Cu(L(2))2]·2H2O (3) and [Zn(L(2))2]·H2O (4) [L(1)(E)-3-(((3-chloro-4-hydroxyphenyl)imino)methyl)naphthalen-2-ol and L(2)(E)-2-chloro-4-((1-(5-chloro-2-hydroxyphenyl)ethylidene)amino)phenol] were synthesized and characterized. A comparative account of analytical, spectroscopic (FT-IR, (1)H and (13)C NMR, Mass, UV-vis and EPR), thermal (TGA/DTA), XRD and SEM studies revealed a correlation between the structure and function of these biologically active molecular entities...
October 11, 2016: Journal of Photochemistry and Photobiology. B, Biology
Sai Zheng, Jia-Chen Shi, Jian-Ying Hu, Wen-Xin Hu, Jing Zhang, Bing Shao
The reaction kinetics and transformation pathways between bisphenol F (BPF) and sodium hypochlorite were investigated at pH values ranging from 6.5 to 8.5 and with different initial concentration ratios. The reaction rate was pH- and free available chlorine (FAC)-dependent: the reaction rate at pH 8.5 was almost 10 times than that at pH 6.5. A total of 40 compounds were tentatively identified as chloro-substituted BPF and polyphenolic compounds by liquid chromatography quadrupole time-of-flight mass spectrometry operating in electrospray ionization mode (LC-ESI-Q-ToF), and 4 main byproducts were confirmed by (1)H and (13)C nuclear magnetic resonance (NMR)...
October 19, 2016: Water Research
Benjamin Paul Wiebenga-Sanford, Joseph A DiVerdi, Christopher D Rithner, Nancy E Levinger
Glucose nanoconfined by solubilization in water-containing AOT (sodium bis(2-ethylhexyl)sulfosuccinate) reverse micelles has been investigated using (1)H NMR. NMR spectra reveal well-defined signals for the glucose hydroxyl groups that suggest slow chemical exchange between them and the water hydroxyl group. Using the EXSY (ZZ-exchange) method, the chemical exchange rate from water to glucose hydroxyl groups was measured for glucose in reverse micelles with size parameter w0=5, 10 and 20, at 25˚ C. The chemical exchange rates observed in the nanoconfined interior are dramatically slower (5-20 times) than observed for glucose in bulk aqueous solution at the same concentration as the micelle interior...
October 25, 2016: Journal of Physical Chemistry Letters
Samuel L Esarey, Joel C Holland, Bart M Bartlett
We analyze the stability of the non-heme water oxidation catalyst (WOC), Fe(bpmcn)Cl2 toward oxygen and illumination under nonaqueous and acidic conditions. Fe(bpmcn)Cl2 has been previously used as a C-H activation catalyst, a homogeneous WOC, and as a cocatalyst anchored to WO3 for photoelectrochemical water oxidation. This paper reports that the ligand dissociates at pH 1 with a rate constant k = 19.8(2) × 10(-3) min(-1), resulting in loss of catalytic activity. The combination of UV-vis experiments, (1)H NMR spectroscopy, and cyclic voltammetry confirm free bpmcn and Fe(2+) present in solution under acidic conditions...
October 25, 2016: Inorganic Chemistry
Christiane Kiske, Svenja Noerenberg, Miriam Ecker, Xingyue Ma, Tohru Taniguchi, Kenji Monde, Wolfgang Eisenreich, Karl-Heinz Engel
The absolute configurations of chiral β-mercaptoalkanones had been previously assigned on the basis of the 1H NMR anisotropy method using (S)-2-methoxy-2-(1-naphthyl)propionic acid ((S)-MαNP) as chiral auxiliary. This study presents a reinvestigation of the configurations of 4-mercapto-2-pentanone, 1, 4-mercapto-2-heptanone, 2, and 2-mercapto-4-heptanone, 3. Enantiomers of 1, 2 and 3 were obtained by lipase-catalyzed hydrolyses of the respective acetylthioalkanones. Upon derivatization with (S)-MαNP, the configurations of the reaction products were deduced on the basis of the order of the HPLC-elution of the diastereoisomeric thioesters assuming that the sector rule previously developed for secondary alcohols is also valid for thiols...
October 25, 2016: Journal of Agricultural and Food Chemistry
Yuki Hitora, Kentaro Takada, Yuji Ise, Shigeru Okada, Shigeki Matsunaga
LCMS analysis of the extract and a cytotoxicity assay of the HPLC fractions generated from a small-scale extract of a Lipastrotethya sp. marine sponge demonstrated the presence of bisindole alkaloids that were associated with the cytotoxic activity. Two bisindole alkaloids tethered by a guanidino ethylthiopyrazine moiety, dragmacidins G (1) and H (2), were isolated, and their structures were assigned by analysis of the MS and NMR data. They showed moderate cytotoxic activity against HeLa cells.
October 25, 2016: Journal of Natural Products
Bethany G Caulkins, Robert P Young, Ryan A Kudla, Chen Yang, Thomas J Bittbauer, Baback Bastin, Eduardo Hilario, Li Fan, Michael J Marsella, Michael F Dunn, Leonard J Mueller
Carbanionic intermediates play a central role in the catalytic transformations of amino acids performed by pyridoxal-5'-phosphate (PLP)-dependent enzymes. Here, we make use of NMR crystallography - the synergistic combination of solid-state nuclear magnetic resonance, X-ray crystallography, and computational chemistry - to interrogate a carbanionic/quinonoid intermediate analogue in the β-subunit active site of the PLP-requiring enzyme tryptophan synthase. The solid-state NMR chemical shifts of the PLP pyridine ring nitrogen and additional sites, coupled with first principles computational models, allow a detailed model of protonation states for ionizable groups on the cofactor, substrates, and nearby catalytic residues to be established...
October 25, 2016: Journal of the American Chemical Society
Qian Zhang, Junsong Wang, Chao Zhang, Shanting Liao, Pei Li, Dingqiao Xu, Yan Lv, Minghua Yang, Lingyi Kong
Huang-Lian-Jie-Du-Decoction (HLJDD, Oren-gedoku-to in Japanese) is commonly used in traditional Chinese medicine (TCM) to treat ischemic stroke. This study investigated the efficacy of various combinations of the major components of HLJDD, berberine (A), baicalin (B), and jasminoidin (C), on the treatment of ischemic stroke modeled by middle cerebral artery occlusion (MCAO) in rats. The effects of A, B and C individually and their combinations were investigated using proton nuclear magnetic resonance (1H NMR)-based metabolomics complemented with neurologic deficit scoring, infarct volume measurement, biochemistry, histopathology and immunohistochemistry, as well as quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting...
October 13, 2016: Oncotarget
Christian Marquardt, Tobias Kahoun, Andreas Stauber, Gábor Balázs, Michael Bodensteiner, Alexey Y Timoshkin, Manfred Scheer
We report on the synthesis and structural characterization of unprecedented anionic parent compounds of mixed Group 13/15 elements. The reactions of the pnictogenylboranes H2 E-BH2 ⋅NMe3 (1 a=P, 1 b=As) with phosphorus and arsenic centered nucleophiles of the type [EH2 ](-) (E=P, As) lead to the formation of compounds of the type [H2 E-BH2 -E'H2 ](-) (2: E=E'=P; 3: E=E'=As; 4: E=P, E'=As) containing anionic pnictogen-boron chain-like units. Furthermore, a longer 5-membered chain species [H2 As-BH2 -PH2 -BH2 -AsH2 ](-) (5) and a cyclic compound [NHC(dipp) -H2 B-PH2 -BH2 -NHC(dipp) ](+) [P5 B5 H19 ](-) (6) containing a n-butylcyclohexane-like anion were obtained...
October 25, 2016: Angewandte Chemie
Biswaranjan Mohanty, Martin L Williams, Bradley C Doak, Mansha Vazirani, Olga Ilyichova, Geqing Wang, Wolfgang Bermel, Jamie S Simpson, David K Chalmers, Glenn F King, Mehdi Mobli, Martin J Scanlon
We describe a general approach to determine the binding pose of small molecules in weakly bound protein-ligand complexes by deriving distance constraints between the ligand and methyl groups from all methyl-containing residues of the protein. We demonstrate that using a single sample, which can be prepared without the use of expensive precursors, it is possible to generate high-resolution data rapidly and obtain the resonance assignments of Ile, Leu, Val, Ala and Thr methyl groups using triple resonance scalar correlation data...
October 24, 2016: Journal of Biomolecular NMR
Mariete B Moreira, Camila F N Da Silva, Rafaela B P Pesci, Victor M Deflon, Sofia Nikolaou
We synthesized and characterized a series of oxo-centered carbonyl-triruthenium complexes with the general formula [Ru3O(CH3COO)6(L)2(CO)], where L = 2,6-dimethylpyrazine (dmpz) (1), isonicotinamide (adpy) (2), 4-acetylpyridine (acpy) (3), 3-methylpyridine (3-pic) (4), 4-methylpyridine (4-pic) (5), 4-tert-butylpyridine (4-tbpy) (6), 4-(dimethyl)aminopyridine (dmap) (7), or 4-aminopyridine (ampy) (8); we also investigated the photoreactivity of these complexes. Single-crystal X-ray diffraction helped to elucidate the structures of 1·H2O, 7·C2H4Cl2, and 8...
October 25, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Zhi-Zhong Zheng, Liang-Hua Chen, Shao-Song Liu, Yuan Deng, Guo-Hua Zheng, Yue Gu, Yan-Lin Ming
Phyllanthus niruri L., a well-known medicinal plant, has been used as a folk antitumor remedy in the worldwide scale. However, the antitumor components in P. niruri have not been reported. In order to verify the antitumor components of P. niruri and the plants which have the high content of these components, we isolated the antitumor components with bioguided fraction and isolation, by different chromatographic methods from the ethyl acetate fraction of P. niruri., and identified them as ethyl brevifolincarboxylate and corilagin by (1)H-NMR, (13)C-NMR, 2D-NMR, and mass spectrometric analyses...
2016: BioMed Research International
Emmanuel Amabebe, Steven Reynolds, Victoria Stern, Graham Stafford, Martyn Paley, Dilly O C Anumba
Changes in vaginal microbiota that is associated with preterm birth (PTB) leave specific metabolite fingerprints that can be detected in the cervicovaginal fluid (CVF) using metabolomics techniques. In this study, we characterize and validate the CVF metabolite profile of pregnant women presenting with symptoms of threatened preterm labor (PTL) by both (1)H-nuclear magnetic resonance spectroscopy (NMR) and enzyme-based spectrophotometry. We also determine their predictive capacity for PTB, singly, and in combination, with current clinical screening tools - cervicovaginal fetal fibronectin (FFN) and ultrasound cervical length (CL)...
2016: Frontiers in Medicine
Ayat Allah Al-Massaedh, Manuel Schmidt, Ute Pyell, Uwe M Reinscheid
Enantiodiscrimination and enantioseparation are two highly important processes in chemistry, often performed by using NMR spectroscopy and chromatography. For a better understanding of the mechanistic details, the same system should be studied by both methods. In addition, isotropic and anisotropic NMR parameters should be obtained, the latter using alignment media so that residual dipolar couplings and chemical-shift anisotropies can be measured. Consequently, a chiral alignment medium was used for the first time in chiral gel-based capillary electrochromatography with the four stereoisomers of the antimalaria drug mefloquine as test compounds...
October 2016: ChemistryOpen
Dijun Zhang, Weina He, Qianqian Tong, Jun Zhou, Xiurong Su
BACKGROUND: The acquisition of iron is important for the pathogenicity of bacteria and blood. Three different culture environments (Fe stimulation, blood agar plate and normal plate) were used to stimulate Enterobacter cloacae, and their respective pathogenicities were compared at the proteomic, mRNA and metabolomic levels. METHODS: 2D-DIGE combined with MALDI-TOF-MS/MS, RT-PCR and (1)H NMR were used to analyze the differential expression levels of proteins, mRNA and metabolites...
2016: Proteome Science
Tomasz Mroczek, Tomasz Plech, Monika Wujec
Till now, three major spectroscopic techniques, fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, have been used for determination of thiol-thione tautomeric forms. Therefore, a novel analytical concept of discrimination of 1,2,4-triazole-3-thione and 3-thiol tautomers using two high-resolution mass spectrometers has been proposed. It comprises the high-performance liquid chromatography (HPLC) hyphenated with electrospray ionization (ESI)-time-of-flight mass spectrometry (ESI-TOF-MS, positive ion mode) followed by in-source collision-induced dissociation (CID) and low-energy CID-tandem mass spectrometry (MS/MS) analysis measured with a Quadruple-TOF-MS instrument...
October 24, 2016: Journal of Chromatographic Science
William A Cantara, Erik D Olson, Karin Musier-Forsyth
In addition to their role in correctly attaching specific amino acids to cognate tRNAs, aminoacyl-tRNA synthetases (aaRS) have been found to possess many alternative functions and often bind to and act on other nucleic acids. In contrast to the well-defined 3D structure of tRNA, the structures of many of the other RNAs recognized by aaRSs have not been solved. Despite advances in the use of X-ray crystallography (XRC), nuclear magnetic resonance (NMR) spectroscopy and cryo-electron microscopy (cryo-EM) for structural characterization of biomolecules, significant challenges to solving RNA structures still exist...
October 21, 2016: Methods: a Companion to Methods in Enzymology
Min Wang, Shan Xu, Chunjiang Wu, Xiaobo Liu, Hong Tao, Yanli Huang, Yongchan Liu, Pengwu Zheng, Wufu Zhu
Two series of sorafenib derivatives (N-methylpicolinamide-4-oxy) chalcones (5a-o, 7a-e) were synthesized and characterized by NMR and MS. All of the target compounds were evaluated for the cytotoxicity against A549, HepG2, MCF-7, and PC-3 cancer cell lines and some selected compounds were further evaluated for the activity against VEGFR-2/KDR and BRAF kinases. The results indicated that all the compounds showed moderate to good antitumor activity, and the compound 5c showed well cytotoxic activity against HepG2, MCF-7 and PC-3 cell lines with IC50 values of 0...
October 12, 2016: Bioorganic & Medicinal Chemistry Letters
Estefanía Moreno-Gordaliza, Sven J van der Lee, Ayşe Demirkan, Cornelia M van Duijn, Johan Kuiper, Petrus W Lindenburg, Thomas Hankemeier
A new capillary isotachophoresis (cITP) method for lipoprotein profiling with superior lipoprotein coverage compared to previous methods has been developed, resolving twice as many lipoprotein species (18 peaks/fractions) in serum or plasma in less than 9.5 min. For this, a novel mixture of 24 spacers, including amino acids, dipeptides and sulfonic acids, was developed and fine-tuned, using predictive software (PeakMaster) and testing of spiked serum samples. Lipoprotein peaks were identified by serum-spiking with reference lipoproteins...
November 9, 2016: Analytica Chimica Acta
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