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91.
Evgenija A. Djurendić Olivera R. Klisurić Mihály Szécsi Marija N. Sakač Suzana S. Jovanović-Šanta Imre Ignáth Vesna V. Kojić Aleksandar M. Oklješa Marina P. Savić Katarina M. Penov-Gaši 《Structural chemistry》2014,25(6):1747-1758
Tetrakis-, tris-, bis-, and mono salicylic acid derivatives 1–4 were synthesized by reaction of methyl 2-hydroxy benzoate (methyl salicylate) with 2,2-bis (hydroxymethyl) propane-1,3-diol (pentaerythritol) in the presence of sodium. Yields of different salicyloyloxy derivatives were changed by varying the molar ratios of reactants. For compounds 2 and 3, X-ray structure analysis was performed, as well as molecular energy minimization, to define their conformation in terms of their energy minima. Comparison of crystal and energy minimized structures for these two compounds (2 and 3) revealed that the intramolecular hydrogen bonds play an important role, stabilizing conformation of the most part of the molecule. The antioxidant activity and cytotoxicity of the synthesized derivatives were evaluated in a series of in vitro tests, as well as 17β-hydroxysteroid dehydrogenase type 2 inhibition potency. Tetrakis salicyloyloxy derivative 1 expressed the highest antioxidant potency, tris salicyloyloxy derivative 2 was the best inhibitor of 17βHSD2 enzyme, while bis salicyloyloxy derivative 3 showed strong cytotoxicity against prostate and breast cancer cells with no cytotoxicity against healthy cells. 相似文献
92.
HPLC‐MS/MS method for quantitative determination of the novel dual inhibitor of FGF and VEGF receptors E‐3810 in tumor tissues from xenograft mice and human biopsies
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Monique Zangarini Laura Ceriani Ezia Bello Giovanna Damia Roberta Cereda Maria Gabriella Camboni Massimo Zucchetti 《Journal of mass spectrometry : JMS》2014,49(1):19-26
We developed and validated a high‐performance liquid chromatography–tandem mass spectrometry analytical method to measure E‐3810, a novel dual inhibitor of fibroblast growth factor receptor 1 and vascular endothelial growth factor receptor 1–3 in tissues and determined the drug concentration in a biopsy of human breast cancer for the first time. The method is a modification of our previous one in plasma to study the clinical pharmacokinetics of the drug during the phase I/II trial. In view of the changes in matrix, we applied a partial validation protocol to determine recovery, sensitivity, range of linearity, precision, accuracy and stability of the method over three runs in a mouse tumor tissue and liver. The recovery of E‐3810 from liver or tumor homogenate was >69%, and the lower limit of quantification was 5 ng/ml. The method was linear in the concentration range 5.0–500.0 ng/ml, as demonstrated by a determination coefficient R2 ≥ 0.9955. The range of the calibration curve was appropriate for the analysis, as demonstrated by the accuracy, which was between 91.4% and 106.7%. Interday precision and accuracy on quality control samples at 9, 30 and 300 ng/ml were 3.1‐11.2% and 98.3–111.4%, respectively. The assay was applied successfully to determine the intratumor concentration of E‐3810 in different mouse xenograft tumor models and in a biopsy of a patient with breast cancer included in the phase I/II trial of the drug. In mouse tumors, the concentrations of E‐3810 were higher than necessary to exert antitumor activity in vitro (1 µM). Even more of interest was the result obtained in a human biopsy of few milligrams, where E‐3810 reached 4.9 µg/g (11 µM). Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
93.
An Abnormal N‐Heterocyclic Carbene–Carbon Dioxide Adduct from Imidazolium Acetate Ionic Liquids: The Importance of Basicity
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Zsolt Kelemen Barbara Péter‐Szabó Dr. Edit Székely Dr. Oldamur Hollóczki Dzmitry S. Firaha Prof. Dr. Barbara Kirchner Dr. József Nagy Prof. Dr. László Nyulászi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(40):13002-13008
In the reaction of 1‐ethyl‐3‐methylimidazolium acetate [C2C1Im][OAc] ionic liquid with carbon dioxide at 125 °C and 10 MPa, not only the known N‐heterocyclic carbene (NHC)–CO2 adduct I , but also isomeric aNHC‐CO2 adducts II and III were obtained. The abnormal NHC‐CO2 adducts are stabilized by the presence of the polarizing basic acetate anion, according to static DFT calculations and ab initio molecular dynamics studies. A further possible reaction pathway is facilitated by the high basicity of the system, deprotonating the initially formed NHC‐CO2 adduct I , which can then be converted in the presence of the excess of CO2 to the more stable 2‐deprotonated anionic abnormal NHC–CO2 adduct via the anionic imidazolium‐2,4‐dicarboxylate according to DFT calculations on model compounds. This suggests a generalizable pathway to abnormal NHC complex formation. 相似文献
94.
The antioxidant activity (AA), total phenolic content (TPC) and total flavonoids content (TFC) in Dong quai (DQ, Angelica sinensis) raw materials and dietary supplements (DS) containing this plant were determined using the CUPRAC, FRAP and fluorescence methods. The antioxidant activity for DQ aqueous extracts revealed by CUPRAC was (1330.45 ± 1.30) μmol Trolox equivalent (TE) per 100 g of dry mass (DM), whereas the antioxidant activity as determined by FRAP was (1813.9 ± 2.0) μmol of TE per 100 g of DM. Lower values were noted for the fluorescence method than for CUPRAC and FRAP (ranging from (35.96 ± 0.3) to (304.6 ± 1.4) μmol of TE per 100 g of DM). The highest TPC values were determined for an aqueous extract of DQ ((3330.3 ± 2.3) μmol of TE per 100 g of DM), while TFC for ethanolic extracts of DQ was ((146.50 ± 0.5) mg of quercetin equivalent (QE) per 100 g of DM). Cinnamic acid, isomers of benzoic acid and derivatives of quercetin were analysed by HPLC-PDA. The ferulic acid concentration in an ethanolic extract of DQ was (21.83 ± 0.07) mg per 100 g of DM. Of the flavonols detected, rutin exhibited the highest concentration in ethanolic extract of DQ ((3.32 ± 0.13) mg of QE per 100 g of DM). Other phytochemicals (alkaloids, saponins, flavonoids, anthraquinones, tannins, steroids, etc.) were identified by phytoscreening colour reaction. The results were analysed by principal component analysis (PCA), cluster analysis and one-way ANOVA tests. 相似文献
95.
Tamás?Kovács Tamás?Turányi Katalin?F?gleinEmail author János?Szépv?lgyi 《Plasma Chemistry and Plasma Processing》2005,25(2):109-119
Decomposition of carbon tetrachloride in a RF thermal
plasma reactor was investigated in argon atmosphere. The net
conversion of CCl4 and the main products of its decomposition
were determined from the mass spectrometric analysis of outlet
gases. Flow and temperature profiles in the reactor were
calculated and concentration profiles of the species along the
axis of the reactor were estimated using a newly developed
chemical kinetic mechanism, containing 12 species and 34 reaction
steps. The simulations indicated that all carbon tetrachloride
decomposed within a few microseconds. However, CCl4 was partly
recombined from its decomposition products. The calculations
predicted 70\% net conversion of CCl4, which was close to the
experimentally determined value of 60\%. A thermodynamic
equilibrium model also simulated the decomposition. Results of the
kinetic and thermodynamic simulations agreed well above 2000 K.
However, below 2000 K the thermodynamic equilibrium model gave
wrong predictions. Therefore, application of detailed kinetic
mechanisms is recommended for modeling CCl4 decomposition under
thermal plasma conditions. 相似文献
96.
97.
We consider the initial value problem and its renormalisation in the framework of the two-particle-irreducible (2PI) effective action. We argue that in the case of appropriately chosen self-consistent initial conditions, the counterterms needed to renormalise the system in equilibrium are also sufficient to renormalise its time evolution. In this way we improve on Gaussian initial conditions which have the disadvantage of generically not showing a continuum limit. For a more detailed discussion see [Sz. Borsányi and U. Reinosa, arXiv:0809.0496]. 相似文献
98.
D. Kamińska A. Gajos E. Czerwiński D. Alfs T. Bednarski P. Białas C. Curceanu K. Dulski B. Głowacz N. Gupta-Sharma M. Gorgol B. C. Hiesmayr B. Jasińska G. Korcyl P. Kowalski W. Krzemień N. Krawczyk E. Kubicz M. Mohammed Sz. Niedźwiecki M. Pawlik-Niedźwiecka L. Raczyński Z. Rudy M. Silarski A. Wieczorek W. Wiślicki B. Zgardzińska M. Zieliński P. Moskal 《The European Physical Journal C - Particles and Fields》2016,76(8):445
99.
Cosimelli B Frenna V Guernelli S Lanza CZ Macaluso G Petrillo G Spinelli D 《The Journal of organic chemistry》2002,67(23):8010-8018
The title reaction has been studied in dioxane/water in a large (0.1-14.9) pS+ range, evidencing, together with an uncatalyzed process at intermediate (3.5-8.0) pS+ values, the occurrence of a catalyzed pathway both in the acidic (pS+ 0.1-3.5) and in the basic region (pS+ 8.0-14.9): specific-acid catalysis and general-base catalysis, respectively, have been found to take place by means of kinetic investigations at different buffer concentrations. Mechanisms for the three pathways have been advanced on the grounds of structural features. In a comparison with previous data particular attention has been paid to the acid-catalyzed pathway, herein observed for the first time in an azole-to-azole interconversion. The mechanistic hypotheses seem well supported by ab initio calculations. 相似文献
100.
The interaction of q = 0 delta- and lambda-Tb and Eu complexes with poly(dAdT), poly(dGdC) and calf-thymus DNA has been examined by absorption, emission and chiroptical spectroscopy and is sensitive to complex helicity, base-pair type and the nature of the lanthanide excited state. 相似文献