Có 120+ tài liệu thuộc chủ đề "Journal of Chemistry"
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Abstract: Pyridine-3/4-thiocarboxamide derivatives were used as starting materials for the synthesis of the target compounds. With the two derivatives (7, 8) obtained in this last step, phenol and thiophenol derivatives were reacted in acetone in the presence of potassium carbonate. 1 − 9 The S-C=N group in the thiazole core is the toxophoric unit and is vital to the pharmaceutical...
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Applicability of the voltammetric determination of these prodrug candidates was studied by recording their DPVs, carried out in mixed media (Britton Robinson buffer solution + DMF) at various pH values on a pencil graphite electrode (PGE). 1 Some of these compounds are potently toxic or carcinogenic, presenting a considerable danger to the human population, and are widely distributed environmental pollutants...
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A simple automated microplate method for determining reducing sugars in food extracts and synthetic serum using cupric-neocuproine as reductant. Abstract: In the present work, a simple automated microplate method based on cupric ion reduction is described for determining total reducing sugars in food extracts and synthetic serum. The reaction of Cu(II)-Nc (cupric-neocuproine) with reducing sugars was performed in alkaline medium...
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In addition, the reducing power of the novel bromophenols was investigated by Cu 2. Moreover, novel bromophenols were tested against cholinergic enzymes including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in the last part of this study. The presented novel bromophenols showed Ki values in the range of nM against AChE and nM against BChE.. 25 The imbalance between the antioxidant...
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The synergistic effects of the ionic liquid and bismuth film combination as the surface modifier remarkably improved the electrochemical response of the modified sensor. Anodic oxidation of CEF was observed at 0.9 V vs. Under optimum experimental conditions, the IL/Bi/PGE exhibited a linear relationship for CEF concentrations in the range of 0.005–0.5 µ M (R with a detection limit as...
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The target compounds 16–25 were syn- thesized by reacting the corresponding N -(5-substituted-1,3,4-thiadiazol-2-yl)-2-chloroacetamides with ciprofloxacin or norfloxacin. The purity and identity of the synthesized compounds were determined by the use of chromatographic and spectral techniques (NMR, IR, MS, etc.) besides elemental analysis. Antibacterial, antituberculosis, and anti- cancer activity of the target compounds were evaluated against selected strains and cancer cell...
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The present contribution first establishes a method of analyzing electrochemical voltage noise data for NiCd batteries, then follows four samples of batteries in terms of voltage noise throughout their lifetimes.. This noise is expected to be due to variations in the electrochemistry on the electrode surfaces of the battery. After careful analysis, the voltage noise behavior of NiCd batteries does...
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It was found that the replacement of the oxygen atoms with sulfur in the DPP unit led to a smaller RE for both the hole and electron transfer processes. One disadvantage of the sulfur replacement is the twist of the conjugated backbone, which might impair the π − π interactions in the solid state. Reorganization energy (RE) is one of...
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Efficient reductive Claisen rearrangement of prop-2’-enyloxyanthraquinones and 2’-chloroprop-2’-enyloxyanthraquinones with iron powder in ionic liquids. Abstract: A rapid and selective iron-mediated reductive Claisen rearrangement of various prop-2’-enyloxyanthraquinones and 2’-chloroprop-2’-enyloxyanthraquinones to 1-hydroxy-2-(prop-2’-enyl)anthraquinones and anthrafurandiones is pre- sented. All reactions are carried out in a mixture of ionic liquids, [Bzmim]Cl (1-benzyl-3-methylimidazolium chloride) and [Hmim]BF 4 (1-methylimidazolium tetrafluoroborate), in short reaction times (5–35 min)....
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Abstract: New azo dyes bearing 2-pyridone and benzimidazole moieties were prepared using diazotization of 4-(1H- benzo[d]imidazol-2-yl)aniline and coupling of the obtained diazonium salt with substituted 3-cyano-2-pyridones. The UV-Vis spectra of the synthesized dyes were measured in thirteen solvents of different properties at room temperature. An MTT (3,4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl tetrazolium bromide) test was performed to prove the biocompatibility of the investigated...
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One-pot multicomponent synthesis of piperidinium 3,3’-(arylmethylene) bis (2-hydroxynaphthalene-1,4-diones): NMR spectroscopic and X-ray structure. Abstract: A facile synthesis of piperidinium 3,3’-(arylmethylene) bis (2-hydroxynaphthalene-1,4-dione) analogs as or- ganic salts is described by the one-pot pseudo-four-component reaction between 2-hydroxy-1,4-naphthoquinone, aromatic aldehydes, and piperidine. 3,3’-(Arylmethylene) bis (2-hydroxynaphthalene-1,4-diones) are one class of HNQ-containing compounds.. 5 Piperidine and its derivatives have been ubiquitously used in the...
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Removal of toxic metals from canola oil by newly synthesized calixarene-based resin. Abstract: This study describes the synthesis, characterization, and application of a new p−sulfonatocalix[4]arene- based silica resin (calix-resin 5) for the extraction of selected metals, namely Pb, Cd, Co, Ni, Cu and Fe, from canola oil. Synthesis, morphology, purity, and elemental composition of calix-resin 5 were analyzed by FT-IR...
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Synthesis of novel SN38-aspirin prodrugs for the treatment of hepatocellular carcinoma. The in vitro anticancer activities of these compounds on two human hepatocellular carcinoma cell lines (BEL-7404 and HepG2) and preliminary mechanisms of action were explored. Among them, compound 4b significantly inhibited cell viability of HepG2 cells (IC µ M) when compared with CPT- 11 (IC µ M). Furthermore, compound...
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Facile synthesis of IrO 2 nanoclusters and their application as catalysts in the degradation of azo dyes. The formation of IrO 2 nanoclusters was confirmed by the appearance of new absorption peak at 230 nm in UV-vis spectra. Further characterization studies were carried out by FT-IR spectroscopy to investigate the coordination between IrO 2 nanoclusters and stabilizers. The size of...
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The electrode- position of homopolymer and copolymer modified electrodes was carried out on the surface of the PGE via chronocoulom- etry. The capacitive properties of the modified PGEs were investigated in 1 M H 2 SO 4 electrolyte solution by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge methods. Compared with P(Py)/PGE and P(PyrPy)/PGE, the P(PyrPy-co-Py)/PGE composite exhibited the best...
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New triplet silylenes M–Si–M ′ –X along with some unusual cyclic forms (M = Li, Na, and K. Abstract: Comparison of 54 M–Si–M ′ –X species is carried out using quantum mechanical ab initio and DFT computa- tions at B3LYP/6-311 ++G. Stability of triplet M–Si–M ′ –X silylenes increases as functions of electropositivity of α-substituents and of β -substituents. The...
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doi:10.3906/kim-1709-11 h t t p. Host/guest inclusion system of surfactants with β -cyclodextrin as a viable catalyst for one-pot synthesis of mono- and bis (indolyl)methylmalononitriles in. Abstract: In this study, encapsulation processes of cetyltrimethylammonium bromide (CTAB) or sodium dodecyl sulfate (SDS) monomers into the cavity of β -cyclodextrin ( β -CD) were applied to synthesize mono- and bis (in- dolyl)methylmalononitrile...
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Voltammetric determination of phenmedipham herbicide using a multiwalled carbon nanotube paste electrode. Abstract: Phenmedipham is an herbicide used especially in the sugar beet harvest to fight against broad-leaved weeds and studies of its voltammetric behavior and detection have not been done before. The superior properties of carbon nanotubes such as electrical conductivity, mechanical strength, and wide potential ranges make them...
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doi:10.3906/kim-1710-13 h t t p. A novel one-pot and rapid synthesis of polyfunctionalized. Abstract: A one-pot, environmentally friendly, and efficient protocol for the synthesis of novel polyfunctionalized benzo[ a]pyrimido[5’,4’:5,6]pyrido[2,3- c]phenazine derivatives has been reported by a one-pot, four-component sequential reaction between 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamines, benzaldehydes, and 6-amino-1,3-dimethyluracil in the presence of p -TSA as a nontoxic, inexpensive, ecofriendly, and efficacious solid...
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The effect of the preconcentration parameters was investigated. to 102% with relative standard deviations of 3.2% and 2.8% for Cd 2+ and Pb 2. The limits of detection were 0.2 and 0.5 µ g/L for Cd 2+ and Pb 2. The validation of the proposed preconcentration procedure was performed using certified reference materials with satisfactory and compatible results. The proposed...