[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)

No abstract available

[en] Thiadiazole pyrimidines have a broad spectrum of biological activity. The reaction of 2-bromo-7-trifluoromethyl-5-oxo-5 H-1,3,4-thiadiazole [3,2-a] pyrimidine was studied. All synthesized compounds were identified using NMR, infrared spectrometry and mass spectrometry. All synthesized substances were purified by chromatography column over silica gel with a suitable solvent. The yield of the target product under these conditions ranged from 35-90%. (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] 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] 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)

[en] As a result of condensation of 3-allyl-2-thioxo-2,3-dihydro-1H-spiro[benzo[h]quinazoline-5,1'- cycloheptane] -4(6H)-one with 2-bromo-1-phenylethanone and 2-thioxobenzo [h]quinazolines of various structures, 2-methylthio derivatives of spiro[benzo [h]quinazoline-5,1'-cycloheptane] were synthesized. By the transformations of 3-allyl-2-hydrazinyl-3H-spiro[benzo [h]quinazoline-5,1'-cycloheptan] -4(6H)-one, benzhydrazide, hydrazino-carbonothioylbenzamide, arylidenhydrazides, 4-allyl4H-spiro[benzo[h[1,2,4]triazolo[4,3-a]quinazoline-6,1'-cycloheptan]-5(7H)-one and 4-allyl-1-mercapto-4H- spiro [benzo[h][1,2,4]triazolo[4,3-a]quinazoline-6,1'-cyclo-heptan]-5(7H)-one were synthesized. The latter by alkylation with various halides was converted into 1-alkylthio derivatives

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)