[en] The new nitroisofalvones 2a-k were synthesized via nitration of the corresponding isoflavones 1a-f using NH4NO3/TFAA in acetonitrile. The aminoisoflavones 3a-g, also new, were produced by selective reduction of the corresponding nitroisoflavones with SnCl2.2H2O. The nitro- and aminoisoflavones, tested in vitro concerning their effects on the proliferation of endothelial cells showed modest activities. All the new products are fully characterized and the nitro compounds analyzed thoroughly by NMR to allow complete assignment of the proton and carbon resonance and to establish the orientation of nitration. (author)

[en] Introduction: Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative pathology that causes memory loss and several cognitive disorders, such as memory impairment, language difficulties and behavioral changes. This pathology appears with a higher prevalence in individuals with more advanced age (+65 years). Due to the characteristics of AD and its various complementary methods for diagnosis, the objective of this work was to evaluate the Proton Spectroscopy by Magnetic Resonance for diagnosis of this pathology. Methodology: This work refers to a qualitative exploratory literature search. In which searches were carried out on national and international databases, Medline, Scientific Electronic Electronic Library Online (SCIELO), Scholar Google (Google Scholar), Pubmed and Virtual Health Library (Bvs), considering studies in Portuguese languages to be eligible. and English. Results: AD affects mainly people over 60 years of age, increasing the probability with the aging of individuals, since its manifestations occur due to cognitive and memory degradation, thus constituting a neurodegenerative pathology. The diagnosis of AD. (author)

[en] Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via ¹H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic, bis-allylic and allylic protons signals of the chemical bonds, and by the induction period of the Rancimat. Biodiesel samples with metallic ions (Fe and Cu) and with rosemary natural extract were analyzed. The metal compounds showed a catalytic effect in the samples and the rosemary natural extract showed to be efficient by retarding the degradation process. The extract was ineffective in the presence of iron. Through the ¹H NMR spectra was possible to observe changes in the signal intensities of the olefinic, bis-allylic and allylic protons as well as the formation of oxidation products in the biodiesel in the degradation process. (author)

[en] Brazilian gasoline type C can be purchased with octane number as the main difference. This quality parameter directly affects the price. Intermediate formulations may not be easily distinguished from conform samples due to similarity in visual appearance and physicochemical properties. The use of anhydrous ethanol as an additive also influences the octane values of the product. In this context, the present study describes the use of ¹H nuclear magnetic resonance spectroscopy (¹H NMR) associated with chemometrics in the characterization and distinction of gasolines by different octane number. Conform samples of common, premium and blends of common-premium were used. Models of NMR-PCA (principal component analysis) and NMR-SIMCA (soft independent modelling of class analogies) showed a good correlation with the values determined by the standard method. The octane values predicted by the NMRPLS (partial least squares) model achieved a good correlation root mean square errors of prediction (RMSEP = 0.50), with the values determined by the standard method as well. (author)

[en] The semi-synthesis of 11 isatin derivatives was achieved through bimolecular nucleophilic substitution and click chemistry. Seven new compounds were obtained. All chemical structures were determined by infrared spectroscopy (IR), nuclear magnetic resonance spectrometry (NMR) and high-resolution mass spectrometry (HRMS) data. These derivatives were evaluated for their anti-GSK-3β activity and all isatin derivatives (N-alkyl and 1,2,3-triazolic) exhibited strong inhibitory activity, with 2b and 4h exhibiting remarkable potency. In addition, docking studies were performed with 2b and 2e models to unravel the molecular mechanism underlying the polar interactions on the GSK-3β ATP-binding site. (author)

No abstract available

[en] Three novel carboxylic arylhydrazone compounds named 2- oxo propionic acid terephthalal acyl dihydrazone (1), 2-ketoglutaric acid terephthalal acyl dihydrazone (2) and 2-ketoglutaric acid salicyl- hydrazone (3) were prepared and characterized by elemental analysis, IR and 1H NMR. The antibacterial activities of 1 and 2 against wheat rust and coliform were investigated. The results showed that 1 had more excellent antibacterial properties than 2 against both wheat rust and coliform. In addition, the title compounds interaction with calf-thymus DNA (CT-DNA) were measured by fluorescence spectra method which indicating that they combined with CT-DNA by groove binding through hydrogen bonds. (author)

[en] Eight new 2-(3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-on-4-yl-azomethine)phenyl benzenesulfonates (3) were obtained by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4- triazol-5-ones (1) with 2-benzenesulfonyloxybenzaldehyde (2). Moreover, eight N-acetyl derivatives (4) of compounds 3 were obtained. Then, seven new 2-[1-(morpholine-4-yl-methyl)-3-alkyl/aryl-4,5-dihydro-1H- 1,2,4-triazol-5-on-4-yl-azomethine)phenyl benzenesulfonates (5) were obtained by the reactions of compounds 3 with formaldehyde and morpholine. The structures of twenty-three newly synthesized compounds were established from infrared, 1H-NMR, 13C-NMR, MS and UV spectral data. In addition, 3, 4 and 5 type compounds were examined for their in vitro potential antioxidant and antibacterial activities. Three different methods were used for the antioxidant assay and the compounds 5 showed a significant activity for iron-binding. Antimicrobial activity was determined on six bacteria using the agar well diffusion method. (author)

[en] It has been recurring adulterations in fuels (such as gasoline, ethanol and diesel), being necessary the exploration of the use of more modern analytical techniques capable of controlling the quality of these fuels, since some regulated tests may be inefficient to detect the adulteration. Among them, it is highlighted proton nuclear magnetic resonance (¹H NMR) spectroscopy, and portable near infrared spectroscopy (microNIR). In this work, it was studied the conformities of 115 samples of seized fuels (76 of gasoline, 23 of ethanol, and 16 of diesel) by means of standardized techniques with parameters established by the ANP. Results obtained were compared to photometer, MicroNIR and 1^H NMR analyzes. The analyzes carried out by ANP showed four nonconforming samples (one of gasoline and three of ethanol). By the photometric technique, only 14 gasoline samples had ethanol content permitted by legislation (i.e ≈ 27 %v/v). By ¹H NMR analysis, it was possible to verify nonconformities by presence of aromatics and olefins compounds in the gasoline and diesel samples as well as of methanol in fuel ethanol samples. It is also worth noting the efficiency of MicroNIR when combined with unsupervised chemometric methods to indicate nonconformities presented by ¹H NMR and photometry techniques. (author)

[en] This article reports on an easy-to-follow methodology for fish lipids analysis, including the biological sample collection, lipid extraction, sample preparation, nuclear magnetic resonance (NMR) spectroscopy analysis and statistical data analysis, with details on parameters used for the NMR analysis and the care needed in each step execution. As an example of the biological matrix of lipids, for the entire procedure, we have used two Amazonian fish samples. Phenotype factor was taken into account when lipid contents of the Amazonian fish samples were evaluated, such as fish-eating habits in distinct Amazon seasonal periods, the flood and the drought. Results demonstrated the applicability of NMR as a powerful and useful tool for fish oil analysis. The omnivorous (T. elongatus) and the piscivorous (C. monoculus) Amazonian fish differ in composition and distribution of lipids, which show differences not only because of the different eating habits between the two species, but also by the availability and quantity of food along the year, i.e., during the flood and drought Amazon periods. (author)