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841.
Nahid Shahabadi Maryam Mahdavi Avat Taherpour Fatemeh Ghasemhezaveh 《Journal of Coordination Chemistry》2017,70(15):2589-2605
A mononuclear Cu(II) complex, [Cu(FA)2(NO3)2], in which FA is ferulic acid ((E)-3-(4-hydroxy-3-methoxy-phenyl)prop-2-enoic acid), was synthesized and characterized by spectroscopic methods. The main structures of the ligand and its complexes with Cu2+ were optimized by QM calculations. The calculations on the structures of the [Cu(FA)2(NO3)2] complexes forms and the intercalating with DNA profile were undertaken by UHF/PM6 and MMFF94 methods, respectively. In vitro studies (UV-vis spectroscopy, emission titration, circular dichroism techniques, and viscometry) under physiological conditions (Tris-HCl buffer solutions, pH 7.4) showed that the complex interacts with calf-thymus DNA (ct-DNA) via an intercalative binding mode. The thermodynamic parameters, enthalpy change (ΔH), and entropy change (ΔS) showed that the acting forces between Cu(II) complex and ct-DNA mainly included van der Waals interactions and hydrogen bonds. Methylene blue (MB) displacement studies revealed that Cu(II) complex can substitute MB probe in the MB-DNA complex which was indicative of intercalative binding. The theoretical data confirm the experimental results with respect to the mechanism of binding. 相似文献
842.
The paper describes a sensitive method for simultaneous sensing of morphine (MOR) and diclofenac (DCF). The surface of a MgFe2O4/graphite paste electrode was modified with multi-walled carbon nanotubes, and the resulting sensor was characterized by cyclic voltammetry, differential pulse voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The electrode showed an efficient synergistic effect in term of oxidation of DCF and MOR, with sharp oxidation peaks occurring at +0.370 and 0.540 V (vs Ag/AgCl) at pH 7.0. The calibration plot for MOR is linear in the 50 nM to 920 μM concentration range, and the detection limit is 10 nM (at a signal-to-noise ratio of 3). The respective data for DCF are 100 nM to 580 μM, with a 60 nM LOD. The sensor was applied to the determination of MOR and DCF in spiked serum and urine samples, with recoveries ranging between 91.4 and 100.7 %. 相似文献
843.
Luciferin‐Regenerating Enzyme Crystal Structure Is Solved but its Function Is Still Unclear 下载免费PDF全文
Saman Hosseinkhani Elaheh Emamgholi Zadeh Fatemeh Sahebazzamani Farangis Ataei Roohullah Hemmati 《Photochemistry and photobiology》2017,93(2):429-435
Contribution of luciferin‐regenerating enzyme (LRE) for in vitro recycling of D‐luciferin has been reported. According to crystal structure of LRE, it is a beta‐propeller protein which is a type of all β‐protein architecture. In this overview, reinvestigation of the luciferase‐based LRE assays and its function is reported. Until now, sequence of LRE genes from four different species of firefly has been reported. In spite of previous reports, T‐LRE (from Lampyris turkestanicus) was cloned and expressed in Escherichia coli as well as Pichia pastoris in a nonsoluble form as inclusion body. According to recent investigations, bioluminescent signal of soluble T‐LRE–luciferase‐coupled assay increased and then reached an equilibrium state in the presence of D‐cysteine. In addition, the results revealed that both D‐ and L‐cysteine in the absence of T‐LRE caused a significant increase in bioluminescence intensity of luciferase over a long time. Based on activity measurements and spectroscopic results, D‐cysteine increased the activity of luciferase due to its redox potential and induction of conformational changes in structure and kinetics properties. In conclusion, in spite of previous reports on the effect of LRE (at least T‐LRE) on luciferase activity, most of the increase in luciferase activity is caused by direct effect of D‐cysteine on structure and activity of firefly luciferase. Moreover, bioinformatics analysis cannot support the presence of LRE in peroxisome of photocytes in firefly lanterns. 相似文献
844.
The relationship between density of energetic azole‐based compounds and their molecular structure is investigated through quantitative structure‐property relationship (QSPR) approach. The methodology of this work introduces a new model, which related density of azole‐based energetic compounds to the optimum elemental composition, the degree of unsaturation (DoU) of the compounds, presence of nitroimino group in the structural formula, as well as several non‐additive structural parameters. The presence of nitroimino functional group and also increasing the value of nO/nN in the formula of these compounds can enhance their density. The correlation is derived on the basis of experimental density values of 100 azole‐based energetic compounds with different molecular structure as training set. The determination coefficient of the new correlation is 0.923. Also, it has the root mean square deviation (RMSD) and the average absolute deviation (AAD) of 0.038 and 0.030 g · cm–3, respectively. In addition, the correlation gives good predictions for further 25 azole‐based energetic compounds as test set (Q2EXT = 0.901). The predictive ability of the correlation is checked using a cross validation method (Q2LMO = 0.918). The proposed method can also apply for designing novel azole‐based energetic compounds. 相似文献
845.
846.
Fatemeh S. Alavi Rahim Ghadari Mansour Zahedi 《Journal of the Iranian Chemical Society》2017,14(1):19-35
In this study, the binding properties of a set of neurology drugs to human serum albumin (HSA) were studied by docking and molecular dynamic (MD) methods. Based on the RMSD values for the MD simulation processes, the drug–protein complexes are stable. Site II of the HSA shows the best affinity for the studied drugs. Different kinds of interactions, including hydrogen bonding, π-cation interactions, and π–π interactions, are observable between ligand and protein during the MD simulation process. The MMGBSA calculations were done to evaluate the binding energy of the ligands and protein. The calculated energies are in good agreement with the previously reported experimental results. In some cases, there is a direct relation between the calculated binding energy with the half-life of the drugs, as it was expected. 相似文献
847.
Avat Arman Taherpour Ako Yari Fatemeh Ghasemhezaveh Mohammad Ali Zolfigol 《Journal of the Iranian Chemical Society》2017,14(12):2485-2493
The efficiently oxidized various types of 2-substituted imidazolines to the corresponding imidazoles using potassium permanganate supported on silica gel (KMnO4/SiO2) under mild conditions and at room temperature have been reported before. In this study, the competitive concerted, catalytic stepwise (E 1 cb′ Cat .) and E 1 cb′ mechanisms of the oxidative aromatization process of 2-imidazolines to the corresponding imidazoles using KMnO4/SiO2 have been theoretically investigated by DFT-B3LYP/6-31G** method. The achieved data from this computational study confirmed that the reaction occurs by stepwise E 1 cb′ mechanism on the basis of the anomeric effect. 相似文献
848.
Fatemeh Shojaei Naemeh Tavakolinia Adeleh Divsalar Thomas Haertlé Ali Akbar Saboury Mohsen Nemat-Gorgani Maria Pia Abbracchio 《Journal of the Iranian Chemical Society》2014,11(6):1503-1512
Protein aggregation is commonly associated with a large number of neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and other types of pathological conditions. Misfolding and aggregation of a number of peptides and proteins have been found to occur under these conditions. In the present review, some mechanistic features of the events related to the type of structure–function relationships which may define the outcome of the abnormal conditions are discussed. The immunological responses to the aggregates and possible therapeutic strategies for prevention or control of the diseases are also reviewed. Protein aggregation and its effect on human body have become an important issue over the last two decades. Many diseases in human are related to aggregation and misfolding of different kinds of proteins; therefore, diagnosis of causes of the aggregation and their mechanisms which provoke it are important. This review describes the relations between structures and functions of already aggregated proteins, as well as proteins, which only enter initial stages of aggregation. The consequences of aggregations, which provoke many kinds of neurodegenerative disorders, are explained in details and some factors that may influence their severity are described. In addition, the immunologic responses to these aggregates are discussed. Suggestions of plausible therapies of preventing or slowing down the protein condensation diseases are presented. 相似文献
849.
Ahmad Seif Lila Torkashavand Fatemeh Mohammadi 《Central European Journal of Chemistry》2014,12(2):131-139
We have investigated oxygen decorating in the (10, 0) aluminum nitride nanotube (AlNNT) by density functional theory. Band gaps, total (TDOS) and partial (PDOS) densities of state and chemical-shielding isotropic (CSI) and chemical-shielding anisotropic (CSA) have been calculated or determined in three models of the investigated (10, 0) AlNNT: pristine (model.0), O-decorating at the one ring in the middle of AlNNT (Model.1) and O-decorating at the nitrogen mouth of AlNNT (Model.2). The results indicated that the dipole moment does not detect the significant effects of dopant whereas TDOS, PDOS and band gap energies detect notable effects. The CSI and CSA values for the Al and N atoms-contributed to the Al-O bonds or those atoms close to the decorated region, in both models of O-decorated AlNNTs are changed. 相似文献
850.
Design of a New Carbon Paste Electrode Modified with TiO2 Nanoparticles to Use in an Electrochemical Study of Codeine and Simultaneous Determination of Codeine and Acetaminophen in Human Plasma Serum Samples 下载免费PDF全文
A new electrochemical sensor was fabricated via TiO2 nanoparticles onto a carbon paste electrode. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studied the response of the modified electrode toward codeine. The effects of pH, modifier amount, pulse amplitude, and scan rate of potential have been examined. Using DPV, we could measure simultaneously codeine and acetaminophen in one mixture. The detection limits of 0.018 and 0.050 µmol L?1 were achieved for codeine and acetaminophen, respectively. The electrooxidation pathway, transfer coefficient, and standard rate constant, are estimated. The proposed voltammetric sensor was successfully applied to determination of codeine and acetaminophen in human plasma serum samples. 相似文献