Resumo em Inglês:

Lantana caatingensis Moldenke (Verbenaceae) is an endemic plant from northeastern Brazil. However, its chemical composition is almost unknown. This study aimed to characterize the chemical compounds found in L. caatingensis and investigate the antileishmanial potential of its hydroalcoholic extract and polar fractions. Compounds present in the hydroalcoholic extract obtained from L. caatingensis leaves and its polar fractions (ethyl acetate and methanolic) were analyzed by liquid chromatography with a photodiode-array detector coupled to electrospray ionization quadrupole time-of-flight mass spectrometry. An antileishmanial assay was performed in a 96-well plate against Leishmania major promastigotes using resazurin on a plate spectrophotometer and the results were expressed as percentage of growth inhibition. Nine compounds were determined in the investigated extract and fractions, classified as flavonoids, flavonoid C-glycosides and phenylethanoid glycosides. The antileishmanial activity revealed that the hydroalcoholic extract and the ethyl acetate fraction were active against L. major promastigotes with inhibitory concentration of 71.78 and 26.86 µg mL-1, respectively, while the methanolic fraction was inactive (478.40 µg mL-1). This is the first report on the chemical composition and antileishmanial activity of L. caatingensis extracts. These results contribute to further knowledge of species belonging to the Lantana genus.

Resumo em Inglês:

This work aimed to incorporate the active compounds of the jambolan leaf in sunflower seed oil, in order to increase the nutritional quality of the oil. For this purpose, ultrasound-assisted extraction was conducted to establish the process conditions related to temperature, potency, solvent:sample ratio and time to obtain the enriched sunflower seed oil (ESSO). An experimental design was applied to examine the effect of variables (temperature, power, solvent:sample ratio and time) on the extraction mass yield (EMY). The application of maximum temperature, increased power, sample:solvent ratio and time resulted in higher EMY. Maximum theoretical EMY value was 35.16% (60 °C, 100%, 1:12 g mL-1 and 15 min). The characterization of the oils obtained from ESSO and sunflower seed oil (SSO) verified a higher content of flavonoids, phenolic compounds, a large proportion of active compounds, antioxidant activity, content of phytosterols, α-tocopherol and squalene, and induction time for ESSO.

Resumo em Inglês:

The inhibition of the fatty acid amide hydrolase (FAAH), an endocannabinoid system component, emerged as a potentially new therapeutic target for a range of clinical disorders such as acute and chronic pain. Some α-ketoheterocycle derivatives demonstrated interesting analgesic and anti-inflammatory activities in vitro. Ligand-Based Drug Design techniques such as knowledge graph convolutional networks (kGCN) and hologram quantitative structure-activity relationship (HQSAR) using α-ketoheterocycle derivatives from five different datasets were generated to discover the relation between the chemical structures and the inhibition activity. Meanwhile, structure-based drug design simulations as interaction fields (MIF), molecular docking, and ligand sites studies (LSI) from FAAH were performed using Autogrid software and FTmap/FTsite servers. The results of both studies were merged to propose predictive models. The resulting kGCN model demonstrated adequate accuracy area under the curve by receiver operating characteristic (AUC-ROC 0.7922). From contribution maps of the Ligand-Based Drug Design (LBDD) models and the generated probes using MIF and LSI, it was observed that the oxazole ring, the ketone group, and the apolar chain present in the structures of the inhibitors are important, besides the evidence of the Cys269 and Val270 residues importance for the potential interaction, confirmed by carried docking studies. These fragments and structural information can be used to carry out new FAAH potential inhibitors studies and report kGCN as an accurate classification technique.

Resumo em Inglês:

A green supramolecular vortex-assisted microextraction employing a mixture of 1-decanol and tetrahydrofuran (THF) was developed for the simultaneous extraction of pesticides from different classes (insecticides, fungicides, and herbicides) from water and flour samples, followed by their determination in high-performance liquid chromatography with diode array detector (HPLC-DAD). The most favorable results were achieved at pH 6.0 in the presence of 4% (m/v) NaCl, utilizing a low volume of 1-decanol and THF (75 and 400 µL, respectively), a short vortex-assisted extraction time (120 s), and centrifugation time (120 s). These conditions yielded high preconcentration factors ranging from 50.1 to 90.3 and low limits of quantification (LOQs) ranging from 1.3 to 27.3 µg L-1. The intraday (n = 10) and interday (n =1 0) precision, assessed as the percentage of relative standard deviation (RSD), varied from 4.4 to 12.4%. The optimized method was successfully applied to determine the pesticides in water and flour samples, with recoveries ranging from 81 to 111%.

Resumo em Inglês:

Nanocomposites of GO/γ-Fe2O3 were used for magnetic dispersive solid-phase microextraction (m-d-μ-SPE) of six pesticides from river water samples, followed by the determination using high performance liquid chromatography-diode array detection. The synthesis of the nanocomposites is described and characterized using Fourier transform-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. A central composite design was used to optimize the extraction time, sample solution pH, and adsorbent amount. The solvent type and volume for desorption and the effect of the ionic strength for adsorption were also investigated. The optimum adsorption conditions were achieved at 84 min of extraction time, pH 5.4, 115 mg of absorbent, and 1% (m/v) of NaCl, while the desorption solvent selected was 1.0 mL of methanol-acetic acid (9:1, v/v). The limits of detection ranged from 0.1 to 0.9 μg L-1, and a good precision was achieved with relative standard deviation (RSD) lower than 7.6% (n = 10). The accuracy of the method was accessed by recovery tests ranging from 82 to 117% (n = 3, RSD < 8%).

Resumo em Inglês:

This study highlights the synthesis of innovative polyurethane materials derived from Moringa oleifera oils extracted from two distinct sources. The oils were converted into their respective polyols through the in situ generated performic acid method. Diverse material characteristics were observed due to different agroclimatic and cultivation conditions for the sources. Extraction yields were 45.21% (source 1) and 40.32% (source 2), with acid values of 28.70 and 26.00 mg KOH per g of oil, respectively. Oleic acid constituted 79.87 and 67.11% of the oils composition, respectively. Nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR) confirmed the hydroxylation of the oils. FTIR also identified the isocyanate structures in the synthesized polyurethane materials. Gel permeation chromatography analysis revealed a higher oligomer content in the polyol synthesized from the oil extracted from source 2. Thermogravimetric analysis demonstrated enhanced thermal stability post-oil conversion, highlighting decomposition stages for rigid and flexible segments. Differential scanning calorimetry indicated higher unsaturation in the oil extracted from source 1, resulting in an elevated crystallization temperature. Tensile testing showed increased elasticity as the [NCO]/[OH] ratio decreased in the material, emphasizing the influence of polyol and crosslinking agent concentrations on mechanical resistance of polyurethane materials.

Resumo em Inglês:

To discover new bisamide compounds with insecticidal and fungicidal activities, 19 novel cyproflanilide derivatives containing 1,2,4-oxadiazole group were designed and synthesized according to the principle of biologically active factor splicing. Preliminary biological assay data indicated that the majority of target compounds demonstrated significant insecticidal activity against Lepidopteran pests. Meanwhile, compounds 5p and 5q showed 97.22 and 100% lethality against Tetranychus cinnabarinus at 400 mg L-1, which were better than cyproflanilide (41.11% at 400 mg L-1). In addition, it is exciting that we have achieved our initial goals as some of the target compounds exhibited both insecticidal and fungicidal activities. For instance, compounds 5b and 5c showed 59.26 and 74.07% fungicidal activities against Cucumber downy mildew at 400 mg L-1, as well as 100% insecticidal activity against Plutella xylostella and armyworm at 100 mg L-1. Compound 5h showed 100% insecticidal activity against armyworm at 10 mg L-1, and also displayed 66.67% fungicidal activity against Cucumber downy mildew at 400 mg L-1. The inhibition rate of compounds 5l and 5s against Cucumber downy mildew reached 88.89 and 96.30% at 400 mg L-1. This work showed the effectively fungicidal application of 1,2,4-oxadiazole group in bisamide compounds and provides insights for optimal structural design.

Resumo em Inglês:

The essential oil extracted from Anemia tomentosa (EOAT) has shown larvicidal potential against Aedes aegypti, based on methods in vitro and in silico. Chromatographic and spectrometric techniques (gas chromatography-mass spectrometry (CG-MS), gas chromatography-flame ionization detector (GC-FID)), as well as mono and bidimensional nuclear magnetic resonance spectroscopy (NMR) were used to assess 10 essential oil components. Chemical composition of essential oil comprised 87.51% sesquiterpenes, with emphasis on presilphiperfolan-1-ol (42.13%) and silphiperfol-5-ene (19.47%). Larvicidal assay conducted in vitro with EOAT has evidenced potential cytotoxic activity up to 48 h exposure to it; mortality rate observed for A. aegypti larvae exposed to essential oil reached 100%. Study conducted in silico with chemical compounds deriving from the herein investigated plant species has evidenced its potential to inhibit acetylcholinesterase in A. aegypti. Activity of triquinane sesquiterpenes ranging from -6.8 to -8.2 kcal mol-1 stood out in comparison to that of temephos (-7.5 kcal mol-1). Chemical compounds identified in the investigated essential oil presented low human and environmental toxicity, as observed in absorption, distribution, metabolism and excretion, and toxicity (ADMETox) predictions.

Resumo em Inglês:

The genus Trichilia, belonging to the Meliaceae family, comprises ca. 102 species, some of which have been the subject of phytochemical studies. Compounds of different classes with cytotoxic, antimicrobial, and antioxidant activities were isolated from Thichilia. Trichilia pseudostipularis, a native species, is distributed along the entire Brazilian coast, from southern Santa Catarina to Bahia. Due to the inexistence of previous chemical studies, their wood and roots were investigated. Compounds 3,4-dihydro-4-isopropyl-6-methylnaphthalen-1(2H)-one (1), 3,4-dihydro-7-hydroxy-4-isopropyl-6-methylnaphthalen-1(2H)-one (2), and pseudostipulariol (3) were isolated from wood, while the lactone derivate rel-(2S,3S,4R)-3-hydroxy-4-methyl-2-(13”-phenyl-l’-n-tridecyl)-butanolide (4) was isolated from the roots. Compounds 3 and 4 are reported for the first time.

Resumo em Inglês:

Two poly(acrylic acid-b-acrylamide) copolymers, and a poly(acrylic acid) homopolymer were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization and tested for nickel removal from aqueous media. RAFT was used for better interchain composition homogeneity and to facilitate the synthesis of the block copolymers. Liquid-phase polymer-based retention (LPR) was used to compare the nickel binding capacity. Uptake tests were carried out at pH 3.0, 4.0, and 5.0. Nickel adsorption isotherms in the range of 1 to 7 mmol L−1 were achieved and the Langmuir adsorption model was applied. Maximum binding capacity (Qm) of Ni2+ at 298 K depended on the composition of the copolymers and pH. The polyacid block (PAA) was the major structural feature responsible for high values of nickel binding. All materials presented better uptake at higher pH, probably due to polyacid deprotonation and the increase in the electrostatic interactions. Up to approximately 100 mg of nickel per gram of homopolymer could be retained at pH = 5.0. Even though the presence of a poly(acrylamide) block decreases the binding capacity compared to PAA, that block has a specific contribution to nickel binding and can also provide better features to the material as better solubilization, and others.

Resumo em Inglês:

Selenium-containing compounds exhibit diverse biological activities, such as antioxidative, anti-inflammatory, and cancer preventive effects. Using Caenorhabditis elegans as a model organism, we assessed the toxicity, neuroprotective, antioxidant properties, and impact on longevity of 11 selenoacetylenes. Their toxicity and bioactivities varied based on molecular structure. Selenoacetylenes with butyl substituents were toxic to Galleria mellonella larvae. The presence of but-3-in-2-ol radical increased antiprotozoal activity against Tetrahymena pyriformis. Compared to the positive control (Nimitz® EC), selenoacetylenes were less toxic to nematode worms and eggs. Selenoacetylenes significantly reduced amyloid beta (Aβ) paralysis in C. elegans CL4176 worms, increased longevity by 18 to 22%, along with improving survival after oxidative or thermal stress. Galantamine, showed inferior results. These findings enhance our understanding of selenoacetylenes on neuroprotection, antioxidant activity, and longevity in C. elegans. Future mammalian studies will further elucidate mechanisms and explore the potential therapeutic use of selenoacetylenes in treating Alzheimer’s disease and longevity.

Resumo em Inglês:

In this study, we aimed to investigate the anticancer activity of the extract, fractions, and isolated compounds of the flowers of Fridericia platyphylla, and to characterize the bioactive compounds. The chemical diversity of the extracts and fractions was investigated using liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS). We were able to annotate 26 compounds from the classes of flavones, flavonols, flavanones, isoflavones, and cinnamic acid and its derivatives. The dichloromethane fraction showed greater cytotoxicity at a concentration of 100 µg mL−1. In addition, the inhibitory concentrations of the dichloromethane fraction were 22.14 and 30.9 µg mL−1 for MCF-7 and MDA-MB-231 cell lines, respectively, and were capable of inhibiting tumor cell migration. Brachydins A and C were isolated from the dichloromethane fraction and showed the greatest cytotoxicity. The results obtained from this study show the potential biological effect of F. platyphylla flowers as a possible antitumor pharmacological agent.

Resumo em Inglês:

Silver film is commonly used to examine the structure and composition of molecules due to its surface-enhanced Raman scattering (SERS) effect. A simple method for preparing SERS silver films is proposed in this paper by electrodeposition in an amide-based liquid mixture (urea-acetamide-LiBr). The electrochemical behavior of silver in urea-acetamide-LiBr mixture was studied by cyclic voltammetry (CV) and chronoamperometry. It was found that the nucleation mechanism of silver shifts to instantaneous nucleation under diffusion control with increasing overpotential and temperature. The energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) investigations confirmed that the obtained deposits are pure silver. Scanning electron microscopy (SEM) analysis showed that the morphology of the silver deposits depends on the deposition potential and temperature. Rhodamine 6G was used as probe molecules for SERS experiments, showing that these new active substrates have high sensitivity to SERS response with high enhancement factors, of approximately 107, and enable Raman scattering even for diluted solutions.

Resumo em Inglês:

In silico and in vitro tests can reveal promising anti-leishmania activity for natural products and their derivatives. The aim of this study was to investigate in silico the pharmacological activities of potential new chalcones and their leishmanicidal potential in vitro. The in silico study was carried out using the PASS, MolPredictX and Molegro Virtual Docker 6.0 programs. Antiparasitic activity was assessed in axenic promastigote and amastigote forms of Leishmania braziliensis. The cytotoxicity tests used the J77G8 cell line. The chalcones exhibited 50% cytotoxic concentration values (CC50) values > 50 μM. Chalcone 4 (named FERAI) presented the best activity with concentration for 50% of promastigotes and intracellular parasites forms (EC50) of 9.75 ± 1.7 and 10.13 ± 1.7 μM for promastigote and amastigote, respectively. Reactive oxygen species (ROS) testing presented increased ROS levels in the parasite at the FERAI concentrations of 10 μM (56.33%), 20 μM (61.76%) and 30 μM (67.13%). Molecular docking revealed interactions (binding energy) between FERAI and the enzymes UDP-glycosyl pyrophosphorylase (-56.8384), dihydroorotate-dehydrogenase (-132.276) and trypanothione-reductase (-151.281). Our results demonstrated the anti-leishmanial activity of chalcones, especially FERAI, with a noted raising of ROS levels in the parasite. Molecular docking revealed dihydroorotate dehydrogenase and trypanothione reductase as potential pharmacological targets for FERAI.

Resumo em Inglês:

This study presents a solution to solid waste problems, focusing on spent lithium-ion batteries (LiBs) and iron ore tailings (IOT) from the Mariana environmental accident in Brazil. The approach involves the production CoFe2O4 from LiBs and IOT, which serves as a catalyst for solar photo-Fenton reactions for methylene blue (MB) decolorization and as an electrochemical sensor for ascorbic acid (AA) detection. Chemical analysis showed recycling potential, with 45.22 ± 0.22% m m−1 Co from LiBs and 14.9 ± 1.5% m m−1 Fe from IOT, determined by inductively coupled plasma atomic emission spectroscopy (ICP OES) and flame atomic absorption spectrometry (FAAS). The sol-gel synthesized CoFe2O4 exhibited a crystallite size of 51.9 ± 1.3 nm and agglomerated crystal clusters. Recycled-CoFe2O4 exhibited a 98.1% MB decolorization efficiency in 60 min under solar irradiation and remained above 92.3% in all 7 reuse cycles. The electrochemical sensor exhibited a coefficient of determination of 0.9987, a sensitivity of 3.352 ± 0.0428 μA mol L−1, and a limit of detection of 0.5511 µM in the concentration range of 1.96 to 23.08 mmol L−1 for AA detection. This study demonstrates the potential of recycled-CoFe2O4 in an environmentally friendly dye removal and as an electrochemical sensor, offering sustainable waste management and resource utilization with solar energy.

Resumo em Inglês:

Caffeine (CAF) and nicotine (NIC) are emerging contaminants and are among the most consumed substances in the world, making it crucial to monitor these contaminants. In this work, an alternative electrolyte, 2-hydroxyethylammonium acetate (2HEAA) was used for the development of an electroanalytical method for determination and quantification of CAF and NIC, simultaneously, using differential pulse voltammetry (DPV). The system with the 2HEAA electrolyte was characterized by cyclic voltammetry and electrochemical impedance spectroscopy, and the DPV parameters were optimized for the best conditions. The method was validated from a calibration curve obtained which showed limit of detection (LOD) of 0.82 and 6.26 μmol L 1 and limit of quantification (LOQ) of 2.73 and 20.8 μmol L-1 for CAF and NIC, respectively. In the precision analyses, values lower than 10% of relative standard deviation were obtained. In the presence of concomitant inorganic and organic species, the system proved to be selective in the determination of analytes. The method was used to determine the analytes in fortified samples (river water, synthetic urine and commercial milk), obtaining recoveries between 87.25 and 111.40%. The 2HEAA demonstrated high efficiency as an alternative electrolyte with good signal-to-noise ratio, increased analytical sensitivity of the method, in addition to presenting low cost and fast electrolyte preparation.

Resumo em Inglês:

The in silico study aimed to suggest phytochemicals from Commiphora leptophloeos leaves essential oil as therapies against coronavirus disease (COVID-19) (or severe acute respiratory syndrome coronavirus 2, SARS-CoV-2). For that, we used molecular docking (MD), absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters, and pharmacokinetic analysis. MD showed the presence of hydrophobic and hydrogen bonds for nine compounds. β-Selinene and bicyclogermacrene showed the best interaction values with the protein Mpro (ID: 6Y2F) (-5.9) and chimeric receptor complexed with its receptor human ACE2 (ID: 6VW1) (-6.1 and -5.5) proteins, as well as low gastrointestinal and high epithelial absorptions, medium permeability for Caco-2 cells and high epithelial permeability, low oral excretion, and were inhibitors of CYP2C19 and CYP2C9 enzymes. On the other hand, both were not permeable to the blood-brain barrier and inhibitors or substrates for glycoprotein-D, and showed carcinogenic potential, but only β-selinene was considered mutagenic. Although little bioavailable, both presented aspects structurally adequate, being compounds with moderate synthesis difficulty. Therefore, more analyses are necessary to evaluate the mechanism of action and unsatisfactory parameters foreseen in bioinformatic assays.

Resumo em Inglês:

The present work aims to extract and test cashew nut peel oil as a natural antioxidant in the oxidative stabilization of biodiesel. Therefore, determinations of the ideal time of Soxhlet and thermal extractions, Fourier transform infrared spectroscopy (FTIR) analyses, and evaluation of the oxidative stability by Rancimat method were carried out. FTIR analyses revealed that the 3rd cycle of extraction was sufficient to extract all the oil, with an average yield of 30.0%. For the thermal extraction of the laboratory technical cashew nut peel oil, the best extraction, based on statistical analysis, was 60 min, yielding 20.0%. The FTIR analysis of the extracted cashew nut peel oil showed characteristic peaks of phenolic groups and organic acids, showing differences in the intensities of the absorption bands. The oxidative stability showed induction period of 8 h 40 min for the hydraulic press extraction, 10 h 35 min for the Soxhlet extraction, and 10 h 65 min for the industrial technical extraction of the cashew nut peel oil. All values were below the 12-h limit established by the National Agency for Petroleum, Natural Gas and Biofuels (ANP). The technical cashew nut peel oil extracted in the laboratory presented an induction period of 11 h 12 min, close to that recommended by ANP, proving to be a promising natural antioxidant. Cardanol presented satisfactory results with 25 h 22 min, double that suggested by ANP. Thus, cashew nut peel oil showed important and promising results as a natural antioxidant for biodiesel.