[en] Present article is devoted to synthesis of propane -1,2-diol ethers of cholanic acids. The synthesis of propane-1,2-diol esters of a number of cholanic acids has been carried out, their structure has been defined by means of infrared and paramagnetic resonance spectroscopy methods. (author)

[en] Present article considers the coherent states of density matrix qubit for N-level quantum system. This article in general terms discusses the coherent states of qubit matrix for level quantum system in SU (2) and SU (3) and SU (N), which are usually used in quantum information processing. (author)

[en] This article considers the quantum computations based on a multi-level quantum system using nuclear magnetic resonance. Therefore, the author presents quantum calculations based on a multilevel quantum system using nuclear magnetic resonance and nuclear quadrupole resonance (Nqr) on nuclei with spin S ≥12. (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] This article presents the results of synthesis of some new derivatives of 3α, 7β-dihydroxycholanic acid, which proceed along the carboxyl group. The composition and structure of the obtained compounds have been confirmed by infrared and paramagnetic resonance spectroscopy.

[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] Foods with high lipid contents are susceptible to deterioration by oxidative processes that lead to the formation of food rancid. Determining the chemical nature of lipid oxidation products presents a nutritional and health interest due to the possibility of formation of compounds related to the development of degenerative diseases such as Parkinson's and Alzheimer's. In this context, the present study describes the use of nuclear magnetic resonance (NMR) spectroscopy and principal component analysis (PCA) to monitor the formation of oxidation products in Brazilian table margarines subjected to the heat treatment at 80, 100, 120, 140, 160 and 180 ° C. Lipid profiles were characterized by ¹H NMR experiments. Changes due to heat treatment were identified by NMR-PCA models, which indicated triacylglycerol (TAG) as the main descriptor from 160 °C. At this temperature, were identified signals evolution in ¹H NMR spectra whose chemical shifts (δ) indicated the formation of aldehydes and dienes. The results were useful to highlight the need for efficient methods to maintain the oxidative stability of this type of food widely used in industrial and home cooking. (author)

[en] Chemical investigation of the crude PDB extract obtained from the endophytic fungus Schizophyllum commune afforded the pure substances, cyclo(L-Pro-L-Val) (1), uracil (2), cyclo(Pro-Tyr) (3), p-hydroxybenzoic acid (4) and a mixture of Rel.cyclo(Pro-Phe) (5) and Rel.cyclo(Pro-Ile) (6). When cultured in corn, the extract of this fungus yielded N-(2-phenylethyl) acetamide (7) and N-(4-hydroxyphenylethyl) acetamide (8). The structures of all compounds were determined based on the analyses of their MS, 1D and 2D-NMR spectroscopic data. Analysis of the crude extracts obtained from small-scale cultures (in PBD, YM, Nutrient, Czapek, Malt Extract, Corn and Rice) and a large-scale culture (in PDB) by mass spectrometry showed the presence of diketopiperazines 1, 3, 5 and 6. The crude extracts showed promising antioxidant, antifungal and acetylcholinesterase (AChE) inhibitory activities. The metabolites 7 and 8 showed antifungal and AChE inhibitory activities in vitro. This is the first report of the identification and isolation of diketopiperazines, arylethylamides, p-hydroxybenzoic acid in endophytic fungus of the Schizophyllum genus. (author)