Resumo em Inglês:

The toxicological effects of a synthesized pyrazoline derivative 4-(3-(4-bromophenyl))-5 (3,4 dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl) benzene sulfonamide, compound B8, on rainbow trout (Oncorhynchus mykiss) were evaluated by following the activity of the antioxidant enzymes and the hematological parameters. Fish were exposed to variant doses (0.5, 1, and 2.5 mg L-1) of the compound B8 for 48 h. Antioxidant enzymes and activities were measured, and the obtained data were statistically analyzed. Our results showed that concentration at 1 mg L-1 significantly increased the malondialdehyde (MDA) levels (p < 0.05) in the liver and gills of rainbow trout (Oncorhynchus mykiss), while glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were significantly decreased. The increase in MDA levels in the liver and gill could be related to tissue damage induced by oxidative stress after exposure to compound B8. Significant increases in white blood cell count (WBCs), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentrations (MCHC) were obtained (p < 0.05). Moreover, significant decreases were observed in erythrocyte numbers, hemoglobin concentrations, hematocrit levels, and platelet numbers (p < 0.05). The results showed that exposure to high doses (2.5 mg L-1) of the compound B8 caused oxidative stress in the liver and gills of fish and may lead to acute anemia.

Resumo em Inglês:

Nb2O5 is a promising photocatalyst for degradation of organic pollutants and production of H2 (renewable and green fuel) from water is an alternative to overcome environmental and energy concerns. Therefore, the effect of Nb precursor and synthesis method on the Nb2O5 physical-chemical properties and photocatalytic performance were investigated in this work. X-ray diffraction and Raman spectroscopy results showed that synthesis parameters had a significant impact on the structural properties of the materials obtained. The synthesis parameters were able to tune Nb2O5 crystalline phase, morphology and specific surface area. Nb2O5 sample obtained by hydrothermal method resulted in materials with smaller size and homogeneous particles compared to the other samples, which resulted in a higher specific surface area (200 m2 g-1) and surface hydroxylation. Nb2O5 samples were active to promote both the degradation of Rhodamine B and amiloride, the specific surface area and surface hydroxylation play a key role in the performance of the materials. The most active sample for organic pollutant degradation was also active in H2 production, additionally, the decoration with Pt nanoparticles increased its performance. This work describes the effect of synthesis parameters of Nb2O5 on its photocatalytic properties and demonstrates the potential application of this material in heterogeneous photocatalysis.

Resumo em Inglês:

In this work, iron nanoparticles were synthesized by a green and bio-inspired process, using Eucalyptus grandis extract as a reducing and stabilizing agent. The functional groups from the extract were incorporated into the structure of the nanoparticles, as confirmed by infrared spectroscopy. Characteristic peaks of zero-valence iron were observed by X-ray diffraction analysis, besides hematite and goethite. The nanoparticles showed spherical morphology and an average size of 96.4 nm. The zeta potential (|35| mV) indicated good stability. The nanoparticles were used as catalysts for o-phenylenediamine oxidation by H2O2, exhibiting optimal catalytic activity. The kinetic assays were performed, and the Michaelis-Menten model was adjusted to the data (maximum rate reached (Vmax) = 2.0 μmol L-1 s-1 and Michaelis-Menten constant (Km) = 307 µmol L-1). A spectrophotometric method was developed for H2O2 quantification. The analytical curve (18.3 112.6 µmol L-1) showed a good linear fit and limits of detection and quantification of 5.48 and 18.3 µmol L-1, respectively. Thus, the method is very promising, adhering to the principles of green chemistry.

Resumo em Inglês:

The potential of four commercial clones of unripe acerola fruit was investigated regarding a source of nutraceuticals and functional foods for industrial use. The chemical profiling of the BRS 235-Apodi, BRS 236-Cereja, BRS 237-Roxinha, and BRS 238-Frutacor clones was determined by the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS-MS) technique coupled to multivariate statistical analysis, which were then correlated to ABTS•+ radical capture (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power (FRAP) assays in order to measure the antioxidant capacity. A total of 24 bioactive compounds were identified, including high amounts of quercetin-O-hexoside, astilbin, and apigenin, which were correlated to three clones (BRS 235, BRS 237, and BRS 238). On the other hand, the BRS 236 clone presented high contents of ascorbic acid, iso-ascorbic acid, citric acid, procyanidin B trimer, rutin, phenolic compounds, and antioxidant activity. These compounds were additionally found to be strongly associated with the antioxidant capacity of unripe acerola fruits. Therefore, the present study revealed that BRS 236 is a promising clone as an antioxidant source to be used as a functional food or ingredient.

Resumo em Inglês:

Coronavirus disease (COVID-19) pandemic has infected 630 million people and led to 6.59 million deaths worldwide since its outbreak. To control COVID-19 advance, finding new molecules with potential to inhibit viral spread is pivotal. Papain-like protease (PLpro) is one of the most interesting targets of pharmacological inhibition since it is implicated not only in viral replication but also in modulation of host immune response. Natural products are of great interest to the pharmaceutical industry due to their diverse structure and biological activities. The NuBBEDB (Nuclei of Bioassays, Biosynthesis and Ecophysiology of Natural Products Database) is an excellent source of natural products (NPs) from the Brazilian flora. In this study, we performed virtual screening, molecular dynamics, and binding energy analyses of the NuBBEDB library to target severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) papain-like protease (PLpro), the virus’s protease essential for replication. Among the top-ranked molecules, the indole alkaloids raputindoles A, C, and D emerged as potential SARS-CoV-2 inhibitors, showing significant interactions with the pivotal Beta-Loop-2 (BL2) region, including the catalytic Y268 residue. Notably, raputindole D displayed enhanced stabilization of the BL2 region, while raputindole C exhibited superior overall stability. These in silico findings suggest that raputindoles, especially D, might offer therapeutic value against COVID-19, laying the groundwork for further experimental evaluations.

Resumo em Inglês:

Nicotine and glycerol are the two important indexes of reconstituted tobacco and they determine the quality of the reconstituted tobacco. A hand-held near infrared spectrometer was used to collect the spectral data of reconstituted tobacco leaves, and three algorithms of principal component regression, partial least squares and support vector machine were used to build the prediction model of the nicotine and glycerol content in reconstituted tobacco leaves. The experimental results showed that the support vector machine algorithm could achieve the best prediction results compared with principal component regression and partial least squares algorithms. The proposed method can rapidly determine the nicotine and glycerol content of the reconstituted tobacco leaves and it provides a new technical reference for improving the quality of new tobacco.

Resumo em Inglês:

With the increase in the supply of glycerol and its economic devaluation, it is important to develop strategies that add value to this substance. Among the various alternatives, one application is its use as a precursor in the synthesis of new polyesters. Therefore, this work describes the condensation reaction of glycerol with valeric acid, obtaining functionalized glycerol, which was used in the polycondensation reaction with terephthalic acid. The samples were characterized by infrared spectroscopy, thermogravimetric analysis, hydrogen nuclear magnetic resonance and differential scanning calorimetry. Spectroscopic analyses confirmed the conversion of the reagents into esters and polyesters. The polyesters showed superior thermal stability than the individual components, a glass transition temperature of -3.8 °C and adhesive properties on glass, wood, paper and rigid polyvinyl chloride substrates. The adhesive capabilities of the samples were compared with those of commercial adhesives already established in the Brazilian market. Samples of polyesters synthesized through the reaction between functionalized glycerol and terephthalic acid showed adhesive behavior in the range of mechanical resistance observed in commercial adhesives, with an elastic modulus ranging from 60.9 ± 36.0 MPa to 162.1 ± 102.4 kPa, depending on the type of adhesive substrate, behaving either as an elastic and/or thermoplastic adhesive.

Resumo em Inglês:

The total concentrations and the bioaccessible fractions of Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, V and Zn were evaluated in 10 samples of pseudocereals, being 3 of amaranth, 3 of quinoa and 4 of chia. The samples were decomposed in a digester block with a reflux system under conditions optimized and the analyses were performed by microwave-induced plasma optical emission spectrometry. In all grains investigated, the highest total concentrations were found for the macroelements K, Mg and Ca, as well as the microelements Fe, Mn, and Zn. When the bioaccessible fraction was evaluated, negative correlations were observed between the content of total phenolic compounds and the bioaccessibility for most elements, in all samples. Among the elements considered essential in our diet, K (99%) and Cu (59%) presented the highest percentages of bioaccessible fraction. Among those elements considered potentially toxic, Ba did not exceed 15% bioaccessible fraction and Al presented concentrations lower than the limit of detection in all samples.

Resumo em Inglês:

Herein, we report the synthesis and evaluation of four aminoguanidine hydrazone derivatives with different aromatic moieties. This class of compounds presents a series of biological applications. Derivative AGH-3 with an indole nucleus offered the highest antioxidant capacity with results comparable to Trolox in 2,2-diphenyl-2-picrylhydrazyl radical (DPPH•), 2,2-azinobis(3 ethylbenzothiazoline-6-sulfonic acid (ABTS•+), FeIII reduction assay (FRAP), and nitric oxide (•NO) radical scavenging assays. Furthermore, AGH-3 showed the highest antiproliferative activity against human kidney cancer cells (786-0) with concentration necessary to inhibit 50% cell growth (GI50) = 6.3 μM; additionally, in biophysical studies, AGH-3 interacted with ctDNA (biological target model) forming a fluorescent supramolecular complex with a binding constant (Kb) of 2.89 × 103 M-1 with preferentially an intercalator mechanism. The tested compounds revealed the potential of aminoguanidine hydrazones as a strategic class of compounds with multitarget biological activity.

Resumo em Inglês:

This study aimed to investigate the occurrence of photolysis of two relevant antibiotics, sulfamethoxazole and trimethoprim, when present in a Waste Stabilization Pond and its disinfection under tropical irradiance. The influence of pH and matrix components, and the generation of photoproducts during solar exposure were evaluated. The pH-dependent speciation of antibiotics had a greater influence on the photolysis of antibiotics than the water matrix, with higher photodegradation at pH 4.1 than at pH 7.2. Trimethoprim was more susceptible to indirect photolysis, indicated by the steeper influence of the photosensitizers nitrate and humic acid compared to sulfamethoxazole. The photoproducts generated were persistent to photolysis and remained present in the samples up to 70 h irradiation. Wastewater disinfection was achieved after 70 h of solar exposure. Nonetheless, the exposure time required to remove at least 50% of sulfamethoxazole was on average 29 h and of trimethoprim 83 h, at the natural pH of the matrix (pH 7.2). Given that the residence time in Waste Stabilization Pond is 41 h, which corresponds to a maximum of 26 h solar irradiation, the exposure time in Waste Stabilization Pond is not sufficient to completely photodegrade antibiotics or disinfect the effluent, demanding further treatment.

Resumo em Inglês:

A new composite based on acetylene black (AB) and vegetable derivative polyurethane (PU) was prepared and evaluated in the determination of bisphenol A (BPA) in water samples using a differential pulse voltammetric procedure (DPV). DPV pulse amplitude of 50 mV, 10 mV s-1 scan rate and 0.10 mol L-1 phosphate buffer were selected for the analytical studies. An analytical curve was obtained with linear range of 0.1-10 µmol L-1 BPA and a limit of detection of 14.1 nmol L-1. The proposed electrode was used without modifiers and with high sensitivity and low-cost preparation in the determination of BPA in both tap and artesian well waters spiked with 0.30 µmol L-1, with relative errors of 0.81 and 1.0% and recoveries of 102 and 105%, respectively. Interferences from oxytetracycline, furosemide, catechol, methyl viologen chloride and fenitrothion could be overcome by appropriate current measuring, while diclofenac did not interfere.

Resumo em Inglês:

In recent years, solid-state engineering has emerged as a promising method for improving the stability and potency of antibiotics and anti-inflammatory drugs. This study focuses on the design and optimization of the intercalation of levofloxacin (an antibiotic drug) and salicylic acid (an anti-inflammatory drug) into zinc-aluminium-layered double hydroxide galleries using response surface method. Release studies revealed that a burst release phenomenon was observed at the beginning of the release assay, and the pH value (in the range of 5.8-7.4) had very little influence on the levofloxacin and salicylic acid release efficiency. This indicates that zinc-aluminium-layered double hydroxide could be an effective inorganic carrier for levofloxacin and salicylic acid over a wide range of pH values. Four kinetic models were used to study the release kinetics and the drug release mechanism was also discussed. In addition, the intercalation of levofloxacin and salicylic acid into zinc-aluminium-layered double hydroxide exhibited enhanced antibacterial activity against Gram-positive Bacillus subtilis. The cell viability assay revealed non-toxic behavior of levofloxacin and salicylic acid intercalated into zinc-aluminium-layered double hydroxide against the monocyte/macrophage-like cell line.

Resumo em Inglês:

It is important to identify the types of tobacco diseases accurately and take effective control measures in time to improve the efficiency of tobacco planting. In this paper, a hand-held near-infrared spectrometer was used to collect the spectral data of different types of tobacco disease samples. The training models were established via convolutional neural network algorithm. Meanwhile, the traditional classification algorithms support vector machine and back propagation neural network were also compared. The results showed that the prediction accuracy of convolutional neural network algorithm was the highest and the overall performance of the model was the best. The rapid detection method based on a hand-held near-infrared spectrometer and convolutional neural network algorithm could identify tobacco leaf disease species efficiently, non-destructively, quickly and accurately, which provided a new technical reference for tobacco leaf disease species detection and identification.

Resumo em Inglês:

The right to clean water is one of the Sustainable Development Goals from the United Nations Agenda 2030. Industrial activity produces several tons of wastewater daily contaminated with dyes that must be treated. In this sense, the adsorption employing carbon-based materials as adsorbents is one of the most used and efficient processes. In this study, we developed a more sustainable biochar derived from a licuri nutshell (LN), a typical Brazilian lignocellulosic residue, for methylene blue (MB) removal. The chemical treatment of this biochar with sulfuric acid and sodium hydroxide created a functional structure with acid and basic sites. The licuri nutshell modified biochar (LNMB) presented a maximum adsorption capacity of MB of 826.45 mg g-1, while the non-modified biochar and the commercial activated carbon presented only 5.27 and 142.86 mg g-1, respectively. The recyclability of the adsorbents was evaluated, and there was a loss of efficiency in each cycle for every material. However, it is remarkable that LNMB presented in only one adsorption cycle almost six times more MB removal than the commercial material, thus proving its promising feature as a greener adsorbent derived from lignocellulosic waste.

Resumo em Inglês:

Antibiotics can contaminate the environment as a result of improper disposal. The induction of doxycycline in the environment could give rise to lineages of the cucurbit beetle Diabrotica speciosa containing resistant endosymbiotic microorganisms, giving rise to bacterial strains capable of biodegrading these antibiotic residues. This work determined the relationship between the intestinal microbiota of D. speciosa and its ability to biodegrade an antibiotic. Bacterial strains of Enterobacter cloacae and Stenotrophomonas maltophila isolated from the gastrointestinal tract of D. speciosa were evaluated for the biodegradation of doxycycline. An analytical method for the extraction and quantification of doxycycline by high-efficiency liquid chromatography-ultraviolet detection (HPLC-UV) was developed and applied to monitor the biodegradation rates during bacterial growth for nutrient and nutrient-deficient media, both supplemented with the antibiotic. Degradation kinetics showed a decrease in antibiotic concentration after 96 h in saline medium, with recoveries of 63.1 and 87.7% for E. cloacae and S. maltophilia, respectively. Two degradation products were then identified and characterized from the liquid chromatography-high resolution mass spectrometry data after bioassays with E. cloacae. The gastrointestinal tract of insects such as D. speciosa can be a source of useful microbes for biotechnological processes such as the biodegradation of exogenous organic compounds in the environment.

Resumo em Inglês:

In this study, a mixed oxide (SiO2/ZnO/Fe2O3/ZnFe2O4) was prepared using the anode recycled from alkaline batteries and the silt fraction of mining tailings and applied as a photocatalyst under solar irradiation and as a pseudocapacitor. The structure and morphology of the mixed oxide revealed clusters of nanometric particles with rhombic and octahedral shapes. A 23 full factorial design was performed to determine the effect of pH, hydrogen peroxide (H2O2), and photocatalyst on methylene blue (MB) decolorization. The maximum efficiency was 96%, obtained using 2.35 × 10-5 mol H2O2 and 20 mg of photocatalyst at pH 3 for 30 min under solar irradiation. This efficiency remained even after four successive decolorization cycles. Pseudocapacitive properties showed that the mixed oxide exhibited favorable characteristics for application as electrochemical pseudocapacitors due to its high capacitance (87.16 F g-1), energy density (27.24 Wh kg-1) at 524.41 W kg-1 of power density, and reversibility (93%). The studied mixed oxide has excellent potential for use in photocatalytic reactions and electrochemical devices, contributing to environmental sustainability and circular economy.

Resumo em Inglês:

Production of esters, organic compounds with emollient, emulsifying, and aromatic properties is growing due to high demand and their applications in the cosmetics industry. The synthesis of these compounds involves the reaction between a carboxylic acid and an alcohol, which can be catalyzed by lipases. In this context, the objective of this study was to produce mycelium-bound lipases of the fungus Rhizopus oryzae through submerged cultivation, with the aim of applying them in the synthesis of ethylene glycol oleate, ethylene glycol stearate, and isoamyl palmitate esters, which are relevant to the cosmetic industry. The influence of solvent usage (heptane), biocatalyst mass, and acid/alcohol molar ratio was evaluated in the esterification reactions. In the synthesis of the three tested esters, and in the presence of heptane solvent, an equimolar ratio (1:1) of each acid and alcohol with a concentration of 0.01 mol L-1 was utilized. The reactions were performed in agitated Erlenmeyer flasks at 40 °C with an agitation speed of 200 rpm. The lipolytic biomass of Rhizopus oryzae showed better performance in the synthesis of isoamyl palmitate, achieving a maximum conversion of 83% in 24 h of reaction using 0.30 g of lipolytic biomass and the solvent heptane. In addition, it was observed that higher concentrations of catalyst biomass (0.45 g) and lower molar ratios (1:1.5) of acid to alcohol resulted in a higher conversion of isoamyl palmitate ester, reaching conversions of 48.59 and 83.11%, respectively.