A Simple Fluorescent Chemosensor for Detection of Zinc Ions in Some Real Samples and Intracellular Imaging in Living Cells
A new designed fluorescent chemosensor TYMN ((E)-1-((thiazol-2-ylimino)methyl)naphthalen-2-ol) for highly sensitive and selective tracing of trace amount of Zn2+ ions in some real samples was synthesized and characterized. The sensor TYMN can detect Zn2+ ions via fluorescence enhancement with a high selectivity over a wide range of metal ions, especially Cd2+. The sensor showed large fluorescence enhancement upon complexation with Zn2+ and simultaneous color change from yellow to orange. The limit of detection was analyzed to be 0.0311 μ M with a linear dynamic range 0.1-1.0 μ M. The sensor could work in a pH span of 5.0...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Chemical and Spectroscopic Characteristics of Anthrosol (Amazonian Dark Earth) and Surrounding Soil from the Brazilian Amazon Forest: Evaluation of Mineral and Organic Matter Content by Depth
The chemical and spectroscopic characteristics of soil organic matter (SOM) isolated from Amazonian dark earth (ADE) and surrounding soil (SR) were evaluated according to the soil depth. The results showed opposite trends for the soils. While ADE featured SOM with a greater aromatic condensation degree and greater hydrophobicity in the top layer, the SR showed more aliphatic and polar SOM. The SOM arrangement from ADE was less hydrophobic, aromatic, and more polar in depth. In contrast, the SOM from SR showed an increase in molecular weight and hydrophobicity. Besides the aromatic protection in the SOM from ADE, there was ...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Chitosan Nanoparticles Loaded with Carvacrol and Carvacryl Acetate for Improved Anthelmintic Activity
Carvacrol (CV) and carvacryl acetate (CVA) are bioactive compounds that have anthelmintic action and the nanoencapsulation may be an alternative to potentialize their efficacy. The aim of this work was to nanoencapsulate CV and CVA using chitosan/gums and evaluate cytotoxicity and the anthelmintic activity. A 24 factorial experimental design was performed to determine the influence of gum type (arabic or chich á), amount of surfactant and the number of layers in the nanoencapsulation degree. CVA and CV presented encapsulation efficiency (EE) optimum values of 90 and 20% (experiments 8 and 9), respectively. The monolayer a...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

New Synthetic Quinolines as Cathepsin K Inhibitors
This study presents the synthesis of nine 2,4-diphenylquinolines, including five phthalonitrile quinolines dyads, and the evaluation of their CatK inhibitory activity. Among the evaluated compounds, 4b was the most potent inhibitor with an IC50 (half-maximal inhibitory concentration) value of 1.55 µM (against Z-Phe-Arg-MCA substrate) acting in an uncompetitive inhibition mode. Molecular docking studies provided important information on the interaction of the inhibitor with the enzyme showing that these quinoline derivatives can play an important role as CatK inhibitors. (Source: Journal of the Brazilian Chemical Society)
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Catalytic Dehydration of Glycerol to Acrolein over Aluminum Phosphate Catalysts
Gas phase conversion of glycerol to acrolein over a variety of aluminum phosphate (AlP) catalysts synthesized by a simple replacement reaction method with a variation in calcination temperature (300-700 ºC, AlP-300, AlP-400, AlP-500, AlP-600, and AlP-700, respectively) has been investigated. The textural properties, acidities and coke contents of the samples were also determined. The catalysts were presented in an amorphous state when the AlP sample was calcined below 500 ºC. Further increasing t he calcination temperature promoted the formation of orthorhombic α -AlPO4 crystal. The weak acid sites increased when the ca...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Preparation and Characterization of the β-Cyclodextrin Inclusion Complex with Benzbromarone
Benzbromarone (BZB) is a drug that has diuretic activity and is used in the gout treatment. Its therapeutic efficiency is decreased by its low water solubility (11.8 mg L-1) and highly hydrophobic aspect (logP 2.7), which are responsible for affecting its intestinal absorption and bioavailability. BZB inclusion complex (IC) aims at increasing the drug solubility in water and reduce adverse effects resulting in more efficient formulations. The coprecipitation encapsulating method was used to obtain the IC of BZB in β -cyclodextrin ( β -CD) and the complex (BZB@ β -CD) was characterized via physical-chemical analysis. A c...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

A Simple and Effective Liquid-Liquid-Liquid Microextraction Method with Ultraviolet Spectrophotometric Detection for the Determination of Bisphenol A in Aqueous Matrices and Plastic Leachates
This study shows the development and application of an analytical method for the determination of bisphenol A (BPA) in aqueous samples such as tap, river and mineral water and plastic leachates, based on an extensive literature search to understand the gaps for the determination of BPA in aqueous samples. We found that most of the methods in the literature employ some chromatographic strategy, and, to a much lesser extent, non-chromatographic instrumentation. In this scenario, we show an ultraviolet spectrophotometric-based method that can be used for routine analysis. Sample preparation was conducted by means of solvent e...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Antimicrobial High-Density Polyethylene (HDPE)/ZnO Nanocomposites Obtained by in situ Polymerization
Nanostructured zinc oxide (ZnO) prepared by combustion in solution was used to obtain nanocomposites. The ZnO particles were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and scanning electron microscopy (SEM), showing crystallite size of 32 nm and a superficial area of 32.6 m2 g-1. Nanocomposites with 1, 3, and 5 wt.% of ZnO in the polymeric matrix were obtained using the in situ polymerization of ethylene with catalytic activities between 1500-1700 kg (molZr h PE)-1. The high-density polyethylene nanocomposites (PEZnO) were characterized by thermogravimetric analysis (TGA), differential scanning...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Chemoenzymatic Synthesis and Anti-Inflammatory Activity of Fatty Acid Amides Prepared from Bertholletia excelsa (Brazil Nut) Triglycerides
This study reports the synthesis of fatty acid amides (FAA), analogous to anandamide, prepared from Brazil nut oil (BNO), using Amano lipase from Pseudomonas fluorescens as a catalyst of direct aminolysis, with a good yield (95-68%). The anti-inflammatory effects of BNO and FAA were evaluated by the carrageenan-induced paw edema method. Analysis of the formation of edema showed that these FAA, at all dose used, significantly reduced the development of edema. (Source: Journal of the Brazilian Chemical Society)
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Tenofovir Disoproxil Fumarate: New Chemical Developments and Encouraging in vitro Biological Results for SARS-CoV-2
The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led society to live with a serious public health problem. In this sense, repositioning of antiretrovirals has captured the attention of the scientific community. Tenofovir disoproxil fumarate (TDF) is an antiretroviral compound that is used to treat acquired immune deficiency syndrome (AIDS) and hepatitis B. In this short report, we present a scale-up investigation of TDF by in situ infrared spectroscopy monitoring and a forced degradation study to describe a new degradation product. Finally, we have evaluated TDF in vitro for SARS-CoV...
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Dreaming is a Must, Despite the Current Crisis
(Source: Journal of the Brazilian Chemical Society)
Source: Journal of the Brazilian Chemical Society - July 27, 2020 Category: Chemistry Source Type: research

Synthesis, Characterization and Antimicrobial Activities of Pentacyclic Oxadiazadiborinanes
In this study we have expanded upon a family of substituted pentacyclic oxadiazadiborinane derivatives from the condensation of carbohydrazide with ortho-formylphenyl boronic acid derivatives containing a variety of chemical and physical properties. All new complexes have been characterized fully including two single crystal X-ray diffraction studies which confirm the solid-state structure of these species along with an unusual methanol activation product, which appears to be a minor solid-state side product. The lack of inherent solubility of these compounds in common physiological media precluded us from doing traditiona...
Source: Journal of the Brazilian Chemical Society - July 3, 2020 Category: Chemistry Source Type: research

Pyrimidine Derivatives: QSAR Studies of Larvicidal Activity against Aedes aegypti
The present study investigated the activity of pyrimidine derivatives against Aedes aegypti. Two compounds, 3c and 3d showed excellent larvicide activity. Additionally, quantitative structure-activity relationship (QSAR) models were built using multiple-linear regression and partial least squares with descriptors generated from Dragon and VolSurf+ software, respectively. The best model is obtained with multiple linear regression (MLR), leading to a robust model. Moreover, the QSAR model is validated by means of some internal validation techniques in order to check its reliability, quality and robustness for predicting the ...
Source: Journal of the Brazilian Chemical Society - July 3, 2020 Category: Chemistry Source Type: research

Combined Analytical Py-GC/MS, SEM, FTIR and 13C NMR for Investigating the Removal of Trace Metals from Aqueous Solutions by Biochar
In this study, the efficiency of biochar (BC) produced from sugarcane bagasse at different pyrolysis temperatures (300, 400, 500 and 600 ºC) for simultaneous removal of CdII, PbII, CuII, CrIII, NiII and ZnII ions from aqueous solutions was assessed. All BC were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), 13C nuclear magnetic resonance (13C NMR) and pyrolysis-gas chromatography-mass spec trometry (Py-GC-MS). The effects of pyrolysis temperature, initial adsorbate concentration and adsorbent dosage on adorption capacity of BC were examined through batch experiments. The BC effi...
Source: Journal of the Brazilian Chemical Society - July 3, 2020 Category: Chemistry Source Type: research

A Choline Chloride-Ethylene Glycol Deep Eutectic Solvent Based on Magnetic Polydopamine with Preconcentration and Determination for Sulfonylurea Herbicides in Water Samples
In this study, a novel deep eutectic solvent (DES) containing choline chloride and ethylene glycol was synthesized, and the magnetic polydopamine (PDA) was modified with this deep eutectic solvent to form Fe3O4@PDA-DES. Fourier transformed infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer were used to characterize the proposed adsorbent. Then, this magnetic material was used as an adsorbent in the magnetic solid phase extraction process for the extraction of four sulfonylurea herbicides in water samples. The main parameters relevant to this method were investigated. Under the optimum co...
Source: Journal of the Brazilian Chemical Society - July 3, 2020 Category: Chemistry Source Type: research