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Chủ đề : Journal of Chemistry


Có 80+ tài liệu thuộc chủ đề "Journal of Chemistry"

Effect of pH and β -cyclodextrin on the photophysical properties of lamotrigine

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Abstract:Photophysical properties of lamotrigine (LMT) were investigated at different pH values. Lamotrigine exhibited a broad absorption band at 308 nm that was shifted to 268 nm at pH 2.0 due to protonation (HLMT. Emission spectra of LMT at different pH values showed a single band at 483 nm except for at pH 2.0, where a second band at 502 nm...

Simultaneous determination of copper(II) and zinc(II) via simple acid-base titrimetry using glass pH electrode

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Simultaneous determination of copper(II) and zinc(II) via simple acid-base titrimetry using glass pH electrode. In this study, a new method was developed and reported for simultaneous determination of copper(II) and zinc(II) cations in a mixture by titrimetric methods. Partial least squares 1, one of the multivariate calibration techniques, was used in the analysis of titrimetric data. Copper(II) and zinc(II) were...

Transfer of the protonable surfactant dipalmitoyl-phosphatidylcholine across a large liquid/liquid interface: A voltammetric study

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Transfer of the protonable surfactant dipalmitoyl-phosphatidylcholine across a large liquid/liquid interface: a voltammetric study. Abstract: Adsorption behavior of the zwitterionic phospholipid dipalmitoyl-phosphatidylcholine (DPPC) at the polar- izable liquid/liquid interface formed between water and 1,2-dichloroethane electrolyte solutions is studied taking into account both the pH of the aqueous phase and the concentration of the phospholipid in the organic phase by cyclic...

Spectroscopic and thermodynamic approach to the interaction of nonperipherally substituted cationic phthalocyanines with calf thymus (CT)-DNA

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Abstract: Novel, nonperipherally tetrasubstituted cationic metal-free and metallophthalocyanines (Zn, In) were synthe- sized in the present study. To investigate the spontaneity of the reactions between DNA and novel quaternized phthalocyanines in buffer, thermodynamic parameters were employed.. 11 − 14 Even though most of the water-soluble Pcs dimerize and aggregate in aqueous solution, there are nonaggregated Pcs in the literature. 33...

Voltammetric determination of vanillin in commercial food products using overoxidized poly(pyrrole) film-modified glassy carbon electrodes

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The selectivity of the modified electrode was examined in the presence of metals, inorganic ions, and organic substances. For this purpose, after the poly(pyrrole) electrode was fabricated at the GCE electrode surface via electrochemical polymerization by cyclic voltamme- try, overoxidation of the polymer film was carried out using a chronoamperometric technique. Electrochemical preparation and characterization of PPy films and PPy...

Synthesis and biological properties of novel 1-methyl-2-(2-(prop-2-yn-1-yloxy)benzylidene) hydrazine analogues

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1-methyl-2-(2-(prop-2-yn-1-yloxy)benzylidene) hydrazine analogues. Abstract: 1-Methyl-2-(2-(prop-2-yn-1-yloxy)benzylidene)hydrazine analogues were readily prepared in good yields by the reaction of 2-(prop-2-yn-1-yloxy)benzaldehydes and methyl hydrazine. 1 − 5 Hydrazones are important sources for the synthesis of heterocyclic compounds 6 − 8 and they are members of Schiff base family, comprehensively studied because of their catalytic properties in various fields and partly for their biological activity....

A new member of Mo36- polyoxoanion’s family: Synthesis, crystal structure, and physico-chemical properties of K10[Mo36O110(OH)6(H2O)12].38H2O

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Abstract: The new giant Mo 36 polyoxomolybdate formulated as K 10 [Mo 36 O 110 (OH) 6 (H 2 O) 12 ].38 H 2 O (1) was isolated by conventional solution method by the reaction of K 2 MoO 4 and KNO 3 in aqueous solution (pH = 1.8), at room temperature, and structurally characterized by single-crystal X-ray diffraction methods....

The synthesis of new oxindoles as analogs of natural product 3,3′ -bis(indolyl)oxindole and in vitro evaluation of the enzyme activity of G6PD and 6PGD

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The synthesis of new oxindoles as analogs of natural product. 3,3 ′ -bis(indolyl)oxindole and in vitro evaluation of the enzyme activity of G6PD and 6PGD. Therefore, the development of new synthetic methods for the synthesis of indole derivatives is very popular. In this study, new oxindoles with reaction of 4,7-dihydro-1 H -indole (2) and isatin (4) were synthesized as analogs...

Development of a molecularly imprinted polymer-based electrochemical sensor for tyrosinase

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Abstract: For the first time a molecularly imprinted polymer (MIP)-based sensor for tyrosinase is described. This sensor is based on the electropolymerization of scopoletin or o-phenylenediamine in the presence of tyrosinase from mushrooms, which has a high homology to the human enzyme. The measuring signal was generated either by measuring the formation of a product by the target enzyme or...

Protein ion-exchange chromatography on a biomacromolecule-immobilized monolithic cryogel

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The results revealed a typical ion-exchange behavior for the PHEMA-HA stationary phase, and with increasing gradient slope the model proteins were found to elute faster. Dynamic adsorption capacity of PHEMA-HA was obtained by frontal analysis and was found as 4 mg/mL for Lys.. By careful control of some experimental parameters (e.g., the ratio of monomers and solvent, catalyst), their morphology...

Nickel(II)-PPh3 complexes with ONS and ONN chelating thiosemicarbazones: Synthesis and inhibition potential on influenza A viruses

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Cytotoxic activities of the ligands and nickel(II) complexes were determined using the MTT assay in vitro against MDCK cells, and then all the compounds were tested on influenza virus replication by plaque assays. The effects of the compounds on the influenza virus and structure–antiviral activity relationships were discussed based on the donor atoms and S-alkyl substituents.. 5,6 In particular, the...

PEG-peptide conjugate containing cathepsin B degradation unit as a doxorubicin carrier system

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Doxorubicin was attached to the carrier system using amide linkage to give the final form of the DDS, denoted as mPEG-AT3-DOX. mPEG-AT3-DOX exhibited a bimodal size distribution at about 15 and 30 nm independent of pH, whereas the size of the control DDS containing no peptide sequence, mPEG-DOX, was measured as ∼ 15–20 nm. doxorubicin release from both of the...

Synthesis, biological evaluation, and in silico study of some unique multifunctional 1,2,4-triazole acetamides

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7.27 (d, J = 7.8 Hz, 2H, H-3. and m, 2H, H-2. 7.15 (d, J = 7.2 Hz, 1H, H-3. 7.62 (d, J = 8.0 Hz, 2H, H-2. 7.32 (d, J = 8.0 Hz, 2H, H-3. 3.98 (q, J = 7.2 Hz, 2H, O-CH 2. 3.71–3.68 (m, 2H, H e -2 ′ &. 2.54–2.48 (m, 2H, H a -2 ′...

Oxime-containing acetylcholinesterase reactivators and their complexes with Pd(II) and Pt(II) ions: Recent developments

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Abstract: The ability of oxime-containing acetylcholinesterase reactivators BT-07 (K005), BT-08 (K033), BT-07-4M (K074), and obidoxime (H 2 LX 2 , X = Cl. to bind palladium(II) or platinum(II) cations was evaluated in aqueous solutions (pH 7.4) at metal-to-ligand molar ratio varying from 1:10 to 10:1. Spectral changes were monitored within a week after mixing the reagents in the range from...

A novel hypobromous acid scavenging activity assay using p-cresol as a spectrofluorometric probe

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A novel hypobromous acid scavenging activity assay using p-cresol as a spectrofluorometric probe. Abstract: In this study, a novel spectrofluorometric assay based on p-cresol (4-methyl phenol) probe is developed for the measurement of HOBr scavenging activity. It is the first study involving the use of a p-cresol probe for the determination of the HOBr scavenging activity of biothiols. While the...

Electrochemical polymerization of a new alkoxy-bridged dithieno (3,2-B:2’,3’-D) pyrrole derivative

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Electrochemical polymerization of a new alkoxy-bridged dithieno (3,2-B:2’,3’-D) pyrrole derivative. Abstract: A novel alkoxy-bridged dithieno (3, 2-B:2’,3’-D) pyrrole (DTP) derivative was synthesized and its correspond- ing polymer poly(1,2-bis(2-(4H-dithieno[3,2-b:2’,3’-d]pyrrol-4-yl)ethoxy)ethane) (P(DTP-alkoxy-DTP)) was successfully obtained electrochemically. The effects of alkoxy bridge in the structure on the electrochemical and spectroelectro- chemical properties of the polymer were also investigated in detail. The results showed that...

Application of the Taguchi approach to optimize ZnO synthesis via hydrothermally assisted sol-gel method

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Application of the Taguchi approach to optimize ZnO synthesis via hydrothermally assisted sol-gel method. The experimental procedures were defined based on the L9 array for four variables in three levels. The influences of those variables on the response parameters, i.e. Taguchi analysis predicted that the optimized conditions to achieve the highest photoactivity are as follows: Zn-precursor = zinc acetate, pH...

Application of a pencil graphite electrode for voltammetric simultaneous determination of ascorbic acid, norepinephrine, and uric acid in real samples

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Application of a pencil graphite electrode for voltammetric simultaneous determination of ascorbic acid, norepinephrine, and uric acid in real samples. The anodic peaks of AA, NE, and UA in their mixture can be well separated in 0.1 M Britton–Robinson buffer solution at pH 4.0. Under optimum conditions, linear calibration graphs were obtained from the AA, NE, and UA concentration ranges,...

Influence of manganese content on the supercapacitive performance of PbO2–MnO2 electrodes

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Influence of manganese content on the supercapacitive performance of PbO 2 –MnO 2 electrodes. Abstract: PbO 2 –MnO 2 electrodes were prepared by electrochemical codeposition methods. The content of manganese in the electrodes increased with the increase in manganese ion concentration in the solution, which can reach 48.4%. Cyclic voltammetry and galvanostatic charge–discharge measurements were used to evaluate the influence...

Synthesis and biological evaluation of novel chalcones bearing morpholine moiety as antiproliferative agents

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constant ( J ) of these doublets, 15.6 Hz, confirmed the trans-configuration of the chalcones. 1 H NMR (400 MHz, DMSO- d 6 /TMS): δ 3.33 (t, J = 4.8 Hz, 4H, H 2. 3.75 (t,J = 4.8 Hz, 4H, H 1. 7.04 (d, J = 9.2 Hz, 2H, H 5. 7.68 (d, J = 15.6 Hz, 1H, H 8....