Resumo em Inglês:

The present study optimized the extraction process of bioactive compounds present in ginger (Zingiber officinale) dried at 80 °C, using ethanol:water 70:30 (v/v) as solvent. The extracts were evaluated for antioxidant activity by the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical reduction methods and by the chelating activity of FeII ions. It was found that the extraction condition with a temperature of 60 °C and an extraction time of 12 h showed better responses to the tests. Then, the characterization of the compounds was carried out by mass spectrometry and thermal analysis (thermogravimetric (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC)), identifying that the main compounds of ginger were gingerols and shogaols, being confirmed by the intensities and characteristics of the thermal graphs. The inhibition of the enzyme acetylcholinesterase (AChE) was evaluated using the Ellman test, which did not show an inhibitory action. Regarding cytotoxic activity, the free extract and encapsulated in liposomes were tested, showing antiproliferative effect at different concentrations for human kidney tumor cells (786-0), liver cells (HUH7.5), and Macaca mullata normal kidney cells (LLC-MK2). Given the results obtained, ginger presents itself as a renewable source of bioactive compounds and can be indicated for applications in the pharmaceutical industry.

Resumo em Inglês:

This study deals with a method for Hg determination in multivitamin supplements. Mercury was extracted with L-cysteine prior to its determination using flow injection-cold vapor generation-inductively coupled plasma-mass spectrometry. A miniaturized flow injection system was employed for Hg vapor generation and its introduction in the plasma whereas 1% (v v-1) HCl and 0.005% (m v-1) NaBH4 were used for that purpose. Mercury extraction was carried out using 6 mL of 1% m v-1 L-cysteine and 50 mg of sample. Accuracy was proved by comparing the Hg concentration found using L-cysteine with the Hg concentration found in the sample decomposed using microwave-assisted digestion, and analysis of certified soil. The limits of detection and quantification of the proposed method were 2 and 6 ng g-1 of Hg, respectively. The relative standard deviation was < 10% (n = 5). Five samples of multivitamin supplements were analyzed and, in any sample, the tolerable amount of Hg (4.0 µg kg-1 body weight) recommended by the World Health Organization was exceeded. The proposed method for Hg determination meets the current legislation and is feasible for Hg monitoring in multivitamin supplements.

Resumo em Inglês:

Heterocycles of the isoxazolone class stand out in the pharmaceutical field because they have numerous biological properties, such as antioxidant, antifungal and antibacterial properties. Thus, isoxazole derivatives have attracted the attention of organic researchers, and several procedures have been developed to obtain these compounds. The present study aimed to synthesize 17 derivatives of isoxazol-5(4H)-ones using a multicomponent reaction catalyzed by an acidic ionic liquid, which allowed yields from 20-96% of the products. To evaluate the bioactivity of the compounds, the synthesized derivatives were analyzed at various concentrations against bacteria and fungi; the derivatives, in general, showed a moderate activity of 125 μg mL-1 against the fungus Candida tropicalis (ATCC 13803) and four derivatives showed an inhibition of < 15.62 μg mL-1 for Gram-positive Staphylococcus epidermidis (ATCC 12228). Furthermore, the antioxidant potential of the derivatives was evaluated by measuring their ability to scavenge 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radicals, resulting in a remarkable reduction percentage of up to 81.06%. To gain further insights into the structure-activity relationships, a principal component analysis was conducted to classify the compounds into active and inactive classes, providing a comprehensive understanding of their bioactivity profiles.

Resumo em Inglês:

Coronavirus disease (COVID-19) pandemic affected several business segments due to the lockdown period, including the illicit drug market. As Brazil usually imports new psychoactive substances (NPS), it was expected that their traffic would change during the pandemic. This study aimed to characterize NPS infused in pieces of paper seized inside prisons in the State of Rio de Janeiro (RJ), Brazil, during the COVID-19 pandemic by gas chromatography coupled with mass spectrometry, attenuated total reflectance-Fourier transform infrared spectroscopy, and high-resolution mass spectrometry. All samples were identified as synthetic cannabinoid receptor agonists, with indole-indazole structures. It was the first record of methyl (2S)-3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido) butanoate (MDMB-4en-PINACA), N-[(2S)-1-amino-3,3-dimethyl-1-oxobutan-2-yl]-1-butylindazole-3-carboxamide (ADB-BUTINACA), and N-(1-adamantyl)-1-(4-fluorobutyl)indazole-3-carboxamide (4F-ABUTINACA) in RJ, demonstrating that new NPS still arrived despite the lockdown. The integration of the data obtained via this study enabled the unequivocal identification of NPS even in the absence of standard reference materials, which is a common drawback faced by forensic laboratories in the analysis of NPS.

Resumo em Inglês:

Dinotefuran is a third-generation neonicotinoid insecticide that has a broad action spectrum in agriculture pests. Dinotefuran was authorized in Brazil in 2019, being classified as a very dangerous product for the environment. Therefore, this study aimed to optimize and validate the solid-liquid extraction with low temperature purification to determine dinotefuran in soil samples using high-performance liquid chromatography coupled diode array detection. The results showed that the best extracting phase was acetonitrile:water (8:2 v/v), followed by the clean-up with 50 mg of primary-secondary amine. The method under these conditions has a linear range of 15.0 to 140 µg k g-1 and reached limits of detection and quantification of 10.0 and 15.0 µg kg-1, respectively. The validation revealed that the method was selective, precise, accurate, and presented a matrix effect of 15%. Although dinotefuran was not detected in real soil samples, the proposed method proved to be an efficient alternative for monitoring dinotefuran in soil samples.

Resumo em Inglês:

A study to establish redox and thermodynamic properties of the protein denaturing agents dithiobutylamine (DTBA) and dithiothreitol (DTT) and of the monoclonal antibody alemtuzumab (ATZ), in aqueous electrolytes, with different pH values, under different experimental conditions, was carried out on a glassy carbon electrode (GCE), using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The voltammetric study demonstrated that DTBA, as well as DTT, were both susceptible to direct electro-oxidation on the electrode surface. The study established that the oxidation of DTBA and DTT took place in three subsequent steps, the first two occurring in the thiol groups forming a cyclic intermediate. The oxidation mechanisms of DTBA and DTT were postulated and proposed. The results using DPV and SWV clearly demonstrated the spontaneous adsorption of ATZ on the hydrophobic GCE surface and that it undergoes electro-oxidation in amino acid residues of tyrosine and tryptophan, exposed superficially on the three-dimensional structure of the protein and on the electrode. An oxidation mechanism of ATZ was also proposed.

Resumo em Inglês:

Determining chemical profiles of complex matrices, such as beers of different styles, can highlight regional characteristics and provide robust literature on the variability of this product, improving quality control. A practical application is to unequivocally attribute the authenticity of the product even in the face of variations in composition due to inadequate transport and storage. This work used proton nuclear magnetic resonance (1H NMR) spectroscopy and chemometrics in the semi-quantitative study of Brazilian ale and lager beers. The results demonstrated the success of applying 1H NMR in characterizing chemical profiles and as a statistical database to distinguish ale and lager beers. Using principal component analysis (PCA) of the NMR data, it was possible to identify that carbohydrate content was responsible for the separation tendency between these beer styles. Ale beers had a higher residual carbohydrate content, according to the integrals of the carbohydrate hydrogens. This is expected, as these beers are obtained by fermentation at higher temperatures for shorter fermentation times. The paper also described soft independent modelling of class analogies (SIMCA) as applied to the NMR data. This class model made it possible to correctly classify 90% of the samples as ale and 100% as lager.

Resumo em Inglês:

Stemodin (1) is a diterpene produced by Stemodia maritima L. (Scrophulariaceae) and shows antiviral and tumor cell proliferation inhibitory activities. Chemical modifications of 1 were performed to produce the known stemodinone (2), two new stemodinone oximes, Z (3) and E (4), and seven new oxime esters derivatives (5, 6, 7, 8, 9, 10, and 11). All derivatives were evaluated for their cytotoxic activity in HL60 (promyelocytic leukemia), SNB-19 (astrocytoma), HCT-116 (colon carcinoma), and PC3 (prostate) human cancer cell lines, and L929 (healthy murine cells). Oximes 3 and 4 showed lower cytotoxic values than 1 against all cancer cell lines tested. However, esters 9 and 10 exhibited cell growth inhibition percentages higher than 1 against PC3, SNB-19, and HCT-116 cancer cell lines, ranging from 62.96 to 94.27%. Many of these values exceed that presented by doxorubicin (66.05-86.87%). All compounds showed no cytotoxic effect on healthy cells at the tested concentration of 25 µg mL-1.

Resumo em Inglês:

In situ transesterification of crambe seeds oil was investigated to produce fatty acid methyl esters using dimethyl carbonate as acyl acceptor and lipase Novozyme 435® as the catalyst. First, the effects of solvent-to-seeds ratio, seed pretreatment, and extraction time were evaluated on the seed oil removal, comparing the results with conventional Soxhlet extraction. Then, the effects of enzyme loading (5 to 30 wt.% based on the oil mass) and reaction time (60 to 540 min) were evaluated on the simultaneous extraction and reaction. The highest oil extraction yield (ca. 26 wt.%) was achieved at the solvent-to-seeds ratio of 6 mL g-1 and 360 min. The oil obtained from seeds that received thermal pretreatment showed a higher concentration of minor compounds. The highest ester content (76.71 wt.%) was obtained with an enzyme loading of 20 wt.%, solvent-to-seeds ratio of 6 mL g-1, for 480 min. The reaction samples showed a predominance of erucate and oleate esters, with identification of the co-products formation (glycerol carbonate and glycerol dicarbonate), and ca. 5 wt.% of acylglycerols.

Resumo em Inglês:

In this research, a meticulous screening process was conducted using four servers: Drug Target Explorer, Swiss Target Predictor, SEA Predictor, and Target Hunter. The primary objective was to identify a series of potential biological targets related to the regulation of cell growth and apoptosis in cancer cells using cinnamic acid derivatives. This study focused on five specific targets, matrix metallopeptidase 9 (MMP9), apoptosis inducing factor (AIF), aldo-keto reductase family 1 member C3 (AKR1C3), aldo-keto reductase family 1 member B10 (AKR1B10), mitogen-activated protein kinase 14 (MAPK14), all of which are well known to play a significant role in cancer cell dynamics. To explore both molecular recognition and molecular dynamics, a series of in silico investigations (docking and molecular dynamics) were carried out using a collection of 14 cinnamic acid derivatives, including cinnamic acid phenethyl ester (CAPE) as a notable reference molecule due to its widely recognized anticancer effects. Furthermore, preliminary in vitro data revealed a potentially promising cytotoxic effect of (E)-N-[(3,4-dichlorophenyl)methyl]-3-(4-phenoxyphenyl)-2-propenamide (LQM755) on a human gastric adenocarcinoma cell-line (AGS cells), which are characterized by the overexpression of the MMP9 protein. Therefore, the chemical compound LQM755 provides an initial perspective in the field of cancer therapy.

Resumo em Inglês:

Glycerol and glycerol-triethanolamine deep eutectic solvent are both environmentally benign, cost-effective, and practical solvents for the Pd-catalyzed Suzuki-Miyaura cross-coupling of aryl halides with arylboronic acids. Utilizing KOH as base, the reaction in glycerol proceeded smoothly with low catalyst loadings (up to 0.5 mol% of PdCl2(PPh3)2) providing excellent yields (up to 99%) of the cross-coupling products, which can be readily extracted with hexane. However, the recyclability of the glycerol medium containing the catalyst is limited to a few cycles. Furthermore, it was explored the use of chlorodiphenylphosphine as a pre-ligand. Although glycerol phosphinite was not generated in situ, PPh2Cl proved to be an excellent pre-ligand, yielding the coupling product with a 98% yield. Compared to glycerol, glycerol-triethanolamine deep eutectic solvent (TEOA:G DES) proves to be a superior solvent for the cross-coupling reaction. In addition, the presence of amine group in the solvent allowed to obtain an inorganic base-free cross-coupling protocol. Aryl bromides and aryl boronic acids containing both electron releasing and attracting functional groups can be coupled without requiring the addition of any further base, affording the biphenyl products in moderate to good yields. The cross-coupling products can be easily isolated by extraction with hexane. Moreover, we observed the formation of triethanolamine phenylboronate during the reaction. The triethanolamine boronate was subsequently synthesized through the condensation of phenylboronic acid with triethanolamine and fully characterized. 11B nuclear magnetic resonance (NMR) spectroscopy confirmed the coordination of the nitrogen to the boron atom of the triethanolamine boronate.

Resumo em Inglês:

The full process of fresh egg preservation presents limitations and is associated with high transportation costs, while processed powdered eggs offer numerous advantages, such as high stability against degradation, providing extended shelf life, easy production, transportation, and favorable storage conditions. Traditional methods for determining the proximate composition of eggs and derivatives lack the capability to eliminate the matrix effect and do not guarantee adequate precision of the results. Therefore, Certified Reference Material (CRM) are the most suitable and effective tool to achieve this purpose. However, in Brazil, CRMs for powdered egg matrix are currently unavailable, although it is not possible to eliminate matrix effects, these can be included in the measurement uncertainty of each CRM. This study aimed to develop a candidate CRM for the powdered egg matrix with the requirements for the competence of testing and calibration laboratories (17034:2016) for proximate composition analyses. The analysis of variance (ANOVA) results for stability and homogeneity indicated no significant variation among the data obtained in the tests and the storage time of the material. Consequently, it was concluded that the powdered egg matrix is stable under simulated transportation conditions (short-term stability) as well as storage conditions (long-term stability) and exhibits adequate homogeneity for a CRM candidate.

Resumo em Inglês:

Refined processed olive oil can indeed become significantly contaminated with polycyclic aromatic hydrocarbons (PAHs). To assess exposure to these contaminants, benzo[a]pyrene (B[a]P) is utilized as a marker due to its known carcinogenicity in humans. The European Commission has established a maximum limit of 2 μg kg-1 for B[a]P in edible oils. However, the analysis of trace amounts of B[a]P in a complex matrix like olive oil poses a persistent challenge. In this study, we have developed a low-temperature liquid-liquid extraction method in combination with constant energy synchronous fluorescence analysis for the determination of B[a]P in olive oil samples. The analyte was extracted from the olive oil using a mixture of acetonitrile and acetone. The performance of fluorescence measurements was evaluated by carefully considering the effects of solvent, temperature, acetone quenching, and slit width for monochromators. The proposed method demonstrates a linear range from 0.8 to 3.2 μg kg-1, with limits of detection and quantification of 0.04 and 0.80 μg kg-1, respectively. Precision and trueness assessments revealed relative standard deviations of less than 10% and recovery rates ranging from 103 to 112%. This method presents an efficient and rapid alternative to sample preparation procedure that minimizes organic solvent consumption.

Resumo em Inglês:

Recycling has experienced great interest over the past five years, primarily driven by its strategic economic significance and the growing scarcity of natural resources. One element that has garnered attention is indium (In), especially due to its presence in flat panel displays (FPDs), particularly in devices utilizing liquid crystal display (LCD). The goal of this research was to establish a method for extracting In from LCD. The study faced challenges related to In determination using inductively coupled plasma optical emission spectroscopy (ICP OES), and furthermore, it proposed an optimized extraction method through design of experiments (DoE), focusing on extraction time and percentage of solid variables. Diverse sample types encompassing smartphones, monitors, and television screens were processed. Leaching was conducted utilizing a magnetic plate at 80 °C, employing a 1 mol L-1 H2SO4 solution along with 25% m v-1 of the sample. This proposed method achieved a near-complete extraction rate (100%) for In. Moreover, in-depth interviews were conducted with several stakeholders in urban mining and various sectors within Brazil. The insights gleaned from these interviews showed the absence of a consolidated market for recycling LCDs with a specific emphasis on In recovery.

Resumo em Inglês:

Urea is the most widely used nitrogen fertilizer worldwide. However, ammonia volatilization, resulting from applying urea to the soil surface, causes economic and environmental losses; thus, urease inhibitors have been developed to mitigate these losses. In this work, the anti-ureolytic activity of Schiff’s base 4-(3-hydroxybenzylideneamino) phenol (3B4) and its amine-derived (3B4a) was evaluated. The most promising urease inhibitor in soil was 3B4 (55.0 ± 3.9% inhibition), with comparable results to N-(butyl) thiophosphoric triamide (p = 0.659). In the in vitro analysis (Canavalia ensiformis), the results of anti-ureolytic activity were similar, 22.6 ± 6.9% for 3B4 and 24.2 ± 9.6% for 3B4a. Biophysical interaction studies were also carried out through molecular docking studies and molecular fluorescence spectroscopy. These studies showed that both substances are preferentially competitive inhibitors, with the interaction between 3B4a and urease forming a more stable complex. In the analysis by Fourier transform infrared spectroscopy, no interaction was observed when 3B4 or 3B4a was mixed with urea (1:1) for 48 h, providing evidence of compatibility. Thus, the Schiff base 3B4 and its corresponding amine 3B4a may represent potential additives for urea fertilization aiming to assist in the urease inhibition process.

Resumo em Inglês:

Lipases have been used in industrial processes as biocatalysts for transesterification reactions. The synergism between enzymes and magnetic properties may be reached by using magnetic nanoparticles (MNPs) as support to immobilize them in aggregate structures, denominated by magnetic crosslinked enzyme aggregates (MCLEA). One of the advantages of such supports is the possibility of using magnetic separation for enzyme recovery, reducing costs and allowing reuse in continuous systems. Here, porcine pancreatic lipase (PPL) was immobilized onto functionalized magnetite support (Fe3O4-APTS) with a protein binding efficiency of 78.84%. Physical and chemical properties of the nanoparticles and immobilized lipase were characterized by X-ray diffraction (XDR), transmission electron microscopy (TEM), infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, vibrating sample magnetometer measurements (VSM), and 57Fe Mössbauer spectroscopy. The immobilized lipase additionally exhibited improved stability across wide pH and temperature ranges compared with free lipase. The immobilized derivate also attained good reusability, maintaining 61.37% of its initial activity after 6 reaction cycles. Through magnetic behavior and also because of its surface modification to crosslinking the enzyme, the MCLEA produced in this work has enhanced the biocatalytic activities of PPL.

Resumo em Inglês:

The application of cyanoacetic acid as a catalyst for the Biginelli reaction and as an active methylene compound for the Knoevenagel condensation reaction was evaluated. Using cyanoacetic acid as a Bronsted acid catalyst, after a synthetic optimization process, it was possible to synthesize eight dihydropyrimidinones with good yields (80-99%) using ethanol as solvent. It is the first time, to our knowledge, that the use of cyanoacetic acid is reported in the synthesis of this class of compounds, which have a wide bioactive potential. Also, cyanoacetic acid was used as a reagent in the Knoevenagel condensation, through which polyfunctionalized olefins were obtained and can be used as building blocks for structurally complex molecules. By using KOH as catalyst, eleven Knoevenagel adducts were synthesized with good yields (65-97%), under microwave irradiation as heating source, in water. Moreover, Knoevenagel adducts containing halogenated substituents (F, Cl) showed potential larvicidal activity with lethal concentrations (LC50) of 19.63, 33.84 µg mL 1 and LC90 of 27.46 and 48.16 µg mL1. This study showed the versatility of cyanoacetic acid as a catalyst for the synthesis of dihydropirimidinones, aldol compounds and presented the first study showing their larvicidal activity against Aedes aegypti.