Resumo em Inglês:

Phloroglucinols comprise polyphenolic compounds abundantly present in biological systems, which are synthesized and accumulated by plants, microorganisms, and marine organisms of different families. Interesting biological activities are associated with these compounds endowed with unique structural characteristics. Because of this, they have become attractive for studies in several areas, such as chemistry and pharmacology. Despite the existence of reputable reviews on phloroglucinol and its derivative compounds, updates on the subject are constant and there are still unexplored specificities of these polyphenols in the literature. Therefore, the present review compiled data on monomeric derivatives of acylphloroglucinols isolated from natural sources. These compounds were grouped into classes considering the oxidation of the central 1,3,5-trihydroxybenzene (THB) ring. Nuclear magnetic resonance (NMR) spectroscopic data and biological activities reported in the literature were associated with the cataloged metabolites considering publications from 1965 to 2022.

Resumo em Inglês:

This study investigates the chemical kinetics of reactive nitrogen species (RNS) formation in plasma-activated water (PAW) using ambient air and evaluates its energy efficiency. A singular plasma/liquid reactor was used, with discharge power varying between 16.4 to 27.0 W and agitation speeds set at 0 and 750 rpm. The reactor operated across temperatures from 5.00 to 35.00 °C during a consistent 180 min plasma activation. Analysis encompassed ionic strength effects, hydronium activity, conductivity, and iodide as a redox indicator for PAW. Findings suggest reactive species predominantly originate in the gas phase and move to the liquid through the gas-liquid interface. HNO3 production in PAW demonstrated a zero-order, temperature-dependent reaction. From activation parameters and ionic strength effects, a determinant step for aqueous HNO3 production was proposed. The influence of discharge power and agitation on HNO3 and HNO2 production was associated with heightened rates due to increased mass transfer and electric field strength. The research highlighted a trade-off between energy efficiency and nitrate production rate, emphasizing an efficiency peak of 72.33 nmol J-1 in PAW, pivotal for cost and operational benefits.

Resumo em Inglês:

Eugenia punicifolia (Kunth) DC. is a medicinal plant used to treat diseases related to oxidative processes. In this work, 1H nuclear magnetic resonance (NMR) spectroscopy and multivariate analysis have been employed to track the chemical changes and antioxidant activity of dimethyl sulfoxide (DMSO) extracts from E. punicifolia leaves over seasons. Principal component analysis (PCA) applied to 1H NMR allowed discriminating DMSO extracts from leaves collected in the dry and rainy seasons and pointed out sucrose, catechin, and epicatechin as responsible for separating dry season samples and quercetin, acid gallic, glucose, and fatty acids contributed for rainy samples grouping. Notably, antioxidant assays revealed that dry season extracts exhibited a higher radical scavenging capacity. When those compounds were submitted to partial least squares-discriminant analysis (PLS-DA) only sucrose and fatty acids presented variable importance projection (VIP) score > 1, both metabolites are related somehow to the defense mechanisms of the plant. This pilot study may suggest new experimental approaches for more effectively monitoring the spectrum-effect relationship of E. punicifolia leaf extracts.

Resumo em Inglês:

The compound 2-hydrazinyl-4-(4-methoxyphenyl)thiazole (PD76) is a novel thiazolyl hydrazine derivative with proven antifungal activity against different fungal species, mainly Candida and Cryptococcus. Considering the advantages of oral route for clinical therapy, the aim of this work was to evaluate the potential intestinal permeability of this new antifungal drug. For the quantitation of PD76, a high-performance liquid chromatography method was developed and fully validated. The cytotoxicity of the compound in Caco-2 cells was analyzed and intestinal permeability of PD76 was assessed by means of the comparison of in vitro assay in Caco-2 cells and in silico platforms ADMETlab and admetSAR. Cell viability above 70% was obtained at all PD76 studied concentrations. Using Caco-2 cell model, the compound showed apparent permeability coefficients (Papp) of 5.25 × 10-6 and 23.28 × 10-6 cm s-1 in apical-basolateral and basolateral-apical directions, respectively. Experiments performed using verapamil as P-gp inhibitor demonstrated that PD76 is slightly susceptible to active efflux. Both in silico platforms inferred that PD76 presents permeability in Caco-2 cells, with Log P values of 2.82 (ADMETlab) and 2.10 (admetSAR). The results obtained in permeability studies showed that PD76 presents moderate intestinal permeability and a promising profile for clinical application.

Resumo em Inglês:

Biodiesel is obtained from the alcoholysis of triglycerides and has been used as a renewable alternative to diesel. Though the methanolysis of triglycerides in the presence of MeONa catalyst has been widely used, searching for alternatives that may improve the competitiveness of the production chain is still a challenge. The aim of this work was to evaluate sodium glyceroxide as a catalyst in the methanolysis of soy oil. Sodium glyceroxide was obtained from glycerol and NaOH in ethanol, and characterized by thermogravimetric analysis (TGA), X-ray powder diffraction (XRD) and, Fourier transform infrared (FTIR) spectroscopy. The transesterification reaction was optimized after two sets of experiments based on the Doehlert matrix experimental design. In the first one, the influence of the molar ratio of methanol/triglyceride, and the amount of catalyst (m/m with respect to the triglyceride) were studied. In the second set, the temperature, and the reaction time were studied. The best conditions were found as 12:1 molar ratio, 2% of catalyst, 50 ºC, and 60 min. The conditions were applied in the transesterification of canola and sunflower oils, and tallow. All the biodiesels were obtained with an ester content superior to 98%, free from methanol and triglycerides. Specific mass, viscosity, and pour point were determined and met the international specifications.

Resumo em Inglês:

In this study, we examine the effects of solvent media on the structural and optical behaviors of two isomers of thiazine derivatives: rac-2-(4-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H 1,3 thiazin-4-one and (2S)-2-(3-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4 one. The solvent effects were modeled using the polarizable continuum model through density functional theory. Electrical parameters for rac-2-(4-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H 1,3-thiazin-4-one and (2S)-2-(3-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4 one were determined using the density functional theory at the CAM-B3LYP/6-311+G(d) level. We studied the influence of isomer structures in various solvent media on the Hyper-Rayleigh-Scattering first hyperpolarizability, considering both static and dynamic scenarios. This research particularly emphasizes the implications of relocating the NO2 group from the meta-position (2S)-2-(3-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4-one to the para-position rac-2-(4-nitrophenyl)-3-phenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4-one on molecular geometries, linear and nonlinear optical parameters, and gap energies across different solvent media. Bond dissociation energy calculations for hydrogen atoms and all other single acyclic bonds were performed for both derivatives to assess degradation and autoxidation properties. Additional insights from non-bonding orbitals, molecular electrostatic surface potential, Fukui calculations, electron localization function, and localized orbital locator are detailed.

Resumo em Inglês:

Wound dressing devices composed of microfibers of poly(butylene-adipate-co-terephthalate) and poly-(ε-caprolactone) incorporated with ibuprofen were obtained by electrospinning technique. The effect of ibuprofen concentration (0, 10, and 20% m m-1) on morphology, spectroscopic, and thermal characterization was evaluated. The fibers containing ibuprofen presented beads and revealed no uniformity. The spectroscopic analysis showed signals that reveal the ibuprofen incorporation on fibers. At the same time, X-ray diffraction spectroscopy indicated a difference in the fiber crystallinity depending on drug concentration, where a lower crystallinity was verified by the film containing a greater concentration incorporated. Rheological measurements revealed that films were more plastic in greater ibuprofen incorporation. Contact angle characterization revealed that ibuprofen solubilization on composite surfaces increased the film wettability. Finally, the fibers promoted the controlled release of ibuprofen, promoting morphological changes in polymeric matrices. The material developed can be used in future biomedical applications.

Resumo em Inglês:

A scalable total synthesis for deoxyrhapontigenin (DRG) was successfully accomplished using low-cost a-resorcylic acid as a starting material. Our approach initiates with the protection of phenolic groups using methoxymethyl, resulting in the synthesis of a derivative of the expensive 3,5-hydroxybenzaldehyde, a critical component for Wittig and Perkin approaches in stilbenoid synthesis. Additionally, the corresponding olefin for Heck reaction and formal synthesis of resveratrol were produced in over 85% yield. The synthesis of deoxyrhapontigenin was accomplished in seven steps from the initial carboxylic acid, yielding a product with an average purity higher than 98%, as confirmed by quantitative nuclear magnetic resonance (NMR) analysis.

Resumo em Inglês:

Tolfenpyrad is an insecticide and acaricide of the pyrazole class, which has been used to control pests in cereal, legume and vegetable crops. Despite its high efficiency, this insecticide is considered highly toxic to humans by Brazilian legislation. Therefore, this study aims to optimize and validate liquid-liquid extraction with low temperature purification followed by analysis by high-performance liquid chromatography with diode array detection to determine tolfenpyrad in water. The results showed that the optimal extraction conditions were achieved using only acetonitrile as extracting phase and 60 min as freezing time. Under these conditions, the extraction method was selective, accurate, and precise, with a recovery of 102.41% and a relative standard deviation of 11.29%. The method was linear from 2.0 to 150.0 μg L-1, with a limit of quantification of 2.0 μg L-1, and the matrix effect was –7.67%. The half-life was 23 days (with sunlight) and 30 days (no sunlight).

Resumo em Inglês:

The catalytic oxidation of glycerol was investigated in assays with palladium-silver bimetallic nanoparticles (Pd-Ag) immobilized on cobalt ferrite (CoFe2O4). Bimetallic nanoparticles were prepared by the galvanic replacement method, immobilized on CoFe2O4 by wet impregnation. Bimetallic Pd-Ag nanoparticles with 35 wt.% Pd content effectively catalyzed the selective oxidation reaction of glycerol to glyceraldehyde. Catalytic oxidation was carried out at 60-80 °C for 2-4 h in an aqueous NaOH solution (NaOH:glycerol ratio = 4 mol:mol) under O2 pressure of 4 bar; the selectivity of glyceraldehyde reached 99.35% and the conversion of glycerol of 49.07% at a temperature of 60 °C and a reaction time of 2 h. Glyceric acid and traces of tartronic acid and mesoxalic acid were also detected. The catalyst was also very stable, showing activity up to 4 runs without significant loss of activity and selectivity.

Resumo em Inglês:

The increase in the number of users, hospitalizations and deaths due to overdose of synthetic opioids made the scientific community to treat this problem as “the opioid crisis”, justifying the need for the development of analytical strategies to identify and quantify these drugs. Even with the global discussion, there is no Brazilian data regarding opioids consumption, addiction or fatal intoxication cases. The aim of this work was to develop, validate and applied an analytical method based on liquid chromatography-tandem mass spectrometry for determination of fentanyl and seven analogues (acetyl norfentanyl, acetyl fentanyl, thiofentanyl, acrylfentanyl, furanylfentanyl, carfentanil and valerylfentanyl) in postmortem blood samples, to the routine analysis of the Forensic Toxicology Laboratory of São Paulo State Police. Linearity was evaluated from 1-500 ng mL-1 (correlation coefficient (r) value (r ≥ 0.99), 1/x weight linear regression), with limit of quantification of 1 ng mL-1. The method imprecision, bias and matrix effect were lower than 19.7%. No interference or carryover were observed, and extraction yield was greater than 57.7%. Analysis of postmortem blood samples (n = 1,359) showed that fentanyl was the most frequently detected opioid. The developed method proved to be useful for routine analysis of the Forensic Toxicology Laboratory.

Resumo em Inglês:

Glycerophospholipids (GP) are important lipids of direct relevance to health and disease, and in marine fish, they are often enriched in omega-3 polyunsaturated fatty acids (PUFA) due to marine microorganisms consumption. It has been speculated that the different diets and habitats to which Amazonian fish are exposed can be ascribed to different lipid compositions, differently than those that occur in marine fish. Here, the GP in Amazonian fish is investigated to achieve nutritional value. Using mass spectrometry and multivariate statistical analysis, we investigated the GP composition of muscles and livers from nine species of wild Amazonian fish. GP profiles mainly comprised a diversity of phosphatidylcholines and varied according to eating habits, the season of capture, and tissue metabolism. In this sense, our results may help in the future aquaculture as a potential source of lipid-based nutrient supplementation to supply food to eradicate global hunger.

Resumo em Inglês:

Isoquinoline alkaloids, especially from the Annonaceae family, have shown biological potential against parasites. Thus, this study aimed to evaluate the potential of the alkaloid fractions of the plant Fusaea longifolia against Plasmodium falciparum and annotate the compounds present in these samples. The tentative characterization of the alkaloids from the leaves and branches of F. longifolia was performed using liquid chromatography coupled to mass spectrometry (LC-MS/MS) and molecular networks. Through manual interpretation of the MS/MS spectra, 18 alkaloids were dereplicated from F. longifolia, 17 of which were reported for the first time in this species. An unpublished putative glycosylated alkaloid was annotated by interpreting the fragmentation data profile. Regarding biological activity, the fractions studied showed high activity against P. falciparum with half-maximal inhibitory concentration (IC50) of 2.42 and 1.60 μg mL-1 for branches and from the leaves, respectively, both similar to the reference standard quinine (IC50 of 1.24 μg mL-1). The structures of the 17 alkaloids were subjected to in silico analysis using molecular docking against four enzymes related to anti-Plasmodium activity (wild type (dm-PfDHFR) and mutant type (qm-PfDHFR), dihydroorotate dehydrogenase (PfDHODH) and purine nucleoside phosphorylase (PfPNP)). Molecular docking revealed strong interactions, especially between oxoxylopine 17 and hydroxycassythicine N-oxide 10, which may be potential new sources against P. falciparum.

Resumo em Inglês:

Pleurotin is a natural compound and potent inhibitor of thioredoxin reductase (TrxR) enzyme, which is a target for cancer chemotherapy. The present study proposes a pharmacophore model for TrxR inhibitors based on the in silico analysis of 34 pleurotin analogues. The results led to ligand 33 with a flexible -SR side-chain at p-quinone and a H-bond donor -CH2NH2 at the oxepane ring. The ligand-TrxR binding free energy was -236 kJ mol 1 for 33, better than pleurotin (-166 kJ mol 1). The results provide a clear and practical guide to design pleurotin derivatives with anticancer potential that could expand the pharmacological potential of this class of natural products.

Resumo em Inglês:

The Metropolitan Region of Rio de Janeiro is one of the most populous in Brazil, besides being one of the most important routes for marketing goods through heavy vehicles. This type of vehicle is the main source of nitrogen oxides (NOx) emission into the atmosphere. To assess NOx emission factors, this pilot study used sensors to monitor in real-time the exhaust of 9 trucks from July to September 2022. To the best of our knowledge, this is the first study carried out in the city using low-cost sensors. Although there is legislation to reduce the emission of pollutants from the vehicle fleet, the results showed that 7 out of 9 trucks, exceeded the stipulated limits, reaching 6 g kWh-1. Furthermore, carrying out the maintenance of the engine of one of the vehicles decreased 60% of the NOx emission, even being an old vehicle. Thus, with this data, it was verified that the sensor performed excellently in monitoring NOx, demonstrating robust performance. This pilot study is part of a project that aims to make a long-term study of NOx emissions factors from heavy-duty diesel vehicles using sensors and other parameters.

Resumo em Inglês:

Poly(oxazoline)s (POZs) are a “new” class of biocompatible polymers that show unique and specific properties for modern biomedical and biomaterials design applications. In this work, POZs-coupled hydroxyethyl starch nanocapsules were developed in order to create a powerful protein suppressor vehicle. Herein, POZs of different molecular weights were used to functionalize the well-known hydroxyethyl starch nanocapsules (HES) surface by metal free “click” chemistry, in which HES have also been related to immune suppressor property. For each modification step, the capsules were characterized regarding size, morphology and charge surface, and, as expected, the “click” strategy kept a core-shell structure with an average diameter distribution < 200 nm. Additionally, previous to the post-polymerization modification step, the amount of free amino groups was determined by fluorescence intensity, allowing further “click” coupling of the surface of the capsules with POZs, later confirmed by gel permeation chromatography. Protein corona evaluation and aggregation assays in human plasma showed lower protein attaching for POZ-modified HES nanocapsules, than HES modified with polyethylene glycol (“PEGylated”-HES) and unmodified HES. Indeed, around 35% of “hard” protein corona of POZ-modified HES are clusterins, the apolipoprotein that can reduce the non-specific cellular uptake into macrophages, indicating that POZs have stealth behavior similar to polyethylene glycol (PEG), being a potential alternative to “PEGylated”-based nanocarriers.

Resumo em Inglês:

This study aims to develop, validate, and evaluate machine learning algorithms for predicting the diagnosis of coronavirus disease (COVID-19), human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), pulmonary tuberculosis (TB), and HIV/TB co-infection. We also investigated potential biomarkers associated with the diagnosis. Data from biochemical and hematological tests of infected and controls were collected in a single general hospital, totalizing 6,418 patients. The discriminant analysis by partial least squares (PLS-DA) model had the highest performance in predicting the diagnosis of COVID-19, HIV/AIDS, TB, and HIV/TB co-infection with an accuracy of 94, 97, 95, and 96%, respectively. The biomarkers calcium, lactate dehydrogenase, red blood cells (RBC), white blood cells, neutrophils, basophils, eosinophils, hemoglobin, and hematocrit were associated with COVID-19. HIV infection was associated with mean corpuscular volume, platelets, neutrophils, and mean platelet volume. Red blood cell distribution width and urea were associated with infection by Mycobacterium tuberculosis. The following biomarkers were associated with HIV/TB co-infection: lymphocytes, RBC, hematocrit, hemoglobin, aspartate transaminase, alanine transaminase, and glycemia. The PLS-DA model can optimize COVID-19, HIV/AIDS, TB, and HIV/TB co-infection diagnostics. Some biomarkers were potential diagnostic indicators and could be evaluated during the screening of these diseases.