Resumo em Inglês:

Seaweeds have been explored by humans for thousands of years as a source of chemical compounds. This study describes the content of minerals, ash, carbohydrates, protein, lipids, and main metabolites of dichloromethane / methanol extracts of the seaweed Ulva lactuca, Padina gymnospora, Palisada perforata and Gelidiella acerosa from sandstone reefs on the Brazilian tropical coast (Pernambuco, Northeastern of Brazil). The content (% dry weight) of carbohydrates ranged from 14.35-48.52, proteins 7.49-14.98, total lipids 0.40-8.92, and ash 18.51-37.02. The concentration (mg kg dry algae−1) of Ca (900-3468), Mg (1655-4902), K (810-1707), Na (1062-4580), Mn (19-4462), and Cu (3.6-6.4) were maximum in Palisada and minimum in Padina. In turn, the lowest and highest contents (mg kg dry algae−1) of Fe (100-2312), Zn (18-43), and Cr (0.08-0.93) were recorded in Gelidiella and Ulva, respectively. Neophytadiene was the major compound. Phytol and palmitic acid were found in all seaweeds, although in low quantities. Palisada had the highest contents (% dry weight) of metabolites (neophytadiene: 23.89, phytol: 8.29; palmitic acid: 8.32), while Ulva had the lowest, except phytone, which was present only in this species. Our findings highlight the potential of these macroalgae from the coastal reefs as a source of chemical compounds.

Resumo em Inglês:

Iron is an important ion that regulates many metabolic functions in the human body, and its deficiency or overload can cause serious health problems. In view of this, the development of tools that can quantify iron in aqueous media is quite valuable. A new material based on a metal-organic framework (MOF) and a calixarene derivative (CALIX), here named CALIX@UiO-66-NH2, was successfully prepared and used as a luminescent sensor for iron ions in a water matrix containing various metal ions. The post-synthetic modification was demonstrated to be efficient on the MOF (UiO-66-NH2) modification, leading to a hybrid platform. The effect of the combination of both components (MOF and CALIX) led to a platform more sensitive to iron detection than the independent compounds. The CALIX@UiO-66-NH2 sensor shows a linear response toward Fe3+ ions with satisfactory linearity (R2 = 0.994) within the concentration range of 6.74 × 10−6−1.72 × 10−5 mol L−1. The limit of detection was determined to be as low as 1.6 mg L−1. The data demonstrate that CALIX@UiO-66-NH2 is an excellent probe for detecting Fe3+, as confirmed by almost complete fluorescence suppression.

Resumo em Inglês:

Cupuaçu (Theobroma grandiflorum Schum.) is an Amazonian fruit rich in antioxidants potential due to its phenolic compounds. Its seeds produce cupulate, a chocolate-like product, and the residue remains rich in biocompounds. This study aimed to optimize and compare microwave-assisted (MAE) and high pressure/temperature extraction (HPTE) of polyphenolic and flavonoid compounds from cupuaçu seed by-products. A Box-Behnken 33 factorial design assessed the influence of extraction time, solid/liquid ratio, and ethanol concentration. Responses included total polyphenol content, total flavonoid content, and anti-radical power via the ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) method. In optimum conditions, MAE had the highest total polyphenol content and HPTE for flavonoids. Optimal conditions for both methods were 65% (m/v) ethanol concentration, 45 min extraction time, and 0.03 g mL−1 solid/liquid ratio. MAE and HPTE achieved greater recovery of (−)-epicatechin and (−)-epigallocatechin-3-gallate compared to percolation. Both techniques proved viable for recovering polyphenols from cupuaçu seed by-products, in less time and with less solvent. Thus, cupuaçu by-products can be a sustainable and functional food source, with MAE and HPTE providing high yields and quality extracts rich in polyphenols.

Resumo em Inglês:

Brazilian Savanna biodiversity is abundant in native fruits with nutritional and sensory properties with potential technological applications. However, the information available regarding the proprieties of Brazilian native fruits is still limited. This study aimed to analyze the metabolic profile of Brosimum gaudichaudii fruits (BGF) using metabolomics approaches, besides its physicochemical and nutritional proprieties. BGF exhibited protein content at least two times higher than other native fruits. Fifty-five metabolites were identified by the metabolomics approaches, mainly fatty acids (n = 22), carbohydrates (n = 13), organic acids (n = 6), and polyphenols (n = 5). The most abundant constituents were D-fructose (42.97%) for sugars, L-asparagine (6.47%) for amino acids, succinic acid (44.11%) for organic acids, and linolenic acid (3.04%) for fatty acids. Highlighted phytochemicals included chlorogenic acid, α-amyrin, and γ-tocopherol. Additionally, this study revealed that BGF is a good source of vitamin C and dietary fiber and an excellent source of vitamin A. Future studies providing nutritional information and suggesting consumption methods and potential industrial applications are essential to familiarize consumers with these foods. Additionally, clarifying the appropriate planting and harvesting seasons can revive traditional practices, especially for native fruits like BGF.

Resumo em Inglês:

This research aims to develop a precise and efficient dispersive solid-phase microextraction (DSPE) technique using third-generation polyamidoamine (PAMAM) dendrimer-grafted nanoparticles to quantify benzoylurea pesticides in green tea, black tea, and oolong tea infusions. The extraction efficiency is optimized through single-factor adjustments of key parameters, including adsorbent quantity (5-20 mg), adsorption duration (5-20 min), desorbent identity (methanol, acetonitrile), volume (100-600 μL), sodium chloride concentration (0-10%, m/v), and sample solution pH (3-8). The optimized method demonstrates linearity in the range of 2-500 μg L-1, with limits of detection (LODs) ranging from 0.6-1.5 μg L-1 and limits of quantification (LOQs) from 2.0 5.0 μg L-1. Recovery rates of 81.2-96.0% are achieved, with intra-day relative standard deviations (RSDs) of 1.4-2.8% and inter-day relative standard deviations of 2.0-3.9%, indicating high accuracy and repeatability. The successful application of detecting residues in commercial tea samples underscores the strong potential of the technique to determine benzoylurea analyte levels.

Resumo em Inglês:

Computational predictive approaches present themselves as an attractive alternative in the search for new compounds that may present toxic or growth regulatory activity in Aedes aegypti. Aspergillus species is a producer of secondary metabolites with diverse biological activities. In this study, it was possible to evaluate the pharmacokinetic and toxicological properties in silico, as well as the prediction of the insecticidal biological activities of the juvenile hormone of natural substances produced by the genus Aspergillus. Initially, 187 molecules were cataloged from various species of Aspergillus spp., and only seven molecules of indole alkaloids were found to exhibit a toxic dose 50% (TD50) after conducting toxicity predictions. The molecular dynamic simulation trajectories were utilized to study parameters such as root mean square deviation, root mean square fluctuation, radius of gyration and intermolecular hydrogen bond to understand the behavior and stability of proposed compounds in the binding pocket of the target protein. The N-β-acetyltryptamine molecule showed a binding affinity value of –8.100 ± 0.200 kcal mol-1, which classifies the compound as a potential insecticidal agent against the Aedes aegypti vector.

Resumo em Inglês:

Serial numbers are marks present on several day-to-day objects, created by manufacturers for purposes such as quality control, product tracking and to prevent counterfeiting. In the case of firearms, these characters can be obliterated or damaged by natural processes or intentionally by criminals to prevent positive identification of stolen property. One non-destructive method employed by crime laboratories for the restoration of obliterated characters is the magnetic particle method. The present work aims to study the synthesis and application of waste-made magnetic nanoparticles in the recovery of adulterated markings. A set of analytical-grade materials and metallic waste magnetic nanoparticles were synthesized for comparison purposes. Chemical characterization tests by X-ray fluorescence, morphological tests by scanning electron microscopy (SEM), and magnetization tests by vibrating sample magnetometer (VSM) were performed. The efficacy of the synthesized nanoparticles was tested on 1020 steel plates previously engraved and adulterated by sanding. Both homemade magnetic nanoparticles demonstrated superior performance compared to commercial magnetic particles. The application of homemade magnetic particles, especially using waste as the source of production, decreases the cost of the material and is environmentally friendly. The development of this material makes magnetic serial number restoration a better option for widespread use in forensic procedures.

Resumo em Inglês:

Compared to other species, components of Combretum lanceolatum are still with few data reported in the literature. This work describes the compounds identification, antioxidant and antimicrobial activities of C. lanceolatum twigs. Ethanolic extract (EECLT) from C. lanceolatum twigs was submitted to partition obtaining: hexane (HF), diethyl ether (EEF), ethyl acetate (EAF) and hydromethanolic (HMF) fractions. They were analyzed by gas chromatography-mass spectrometry, high performance liquid chromatography coupled to mass spectrometry and direct insertion mass spectrometry and evaluated for antioxidant assay (2,2-diphenyl-1-picrylhydrazyl (DPPH) method) and antimicrobial assay. Fifty-seven compounds were identified in the fractions. In antioxidant assay, EECLT and EAF demonstrated good antioxidant potential (half maximal effective concentration (EC50): 57.9 and 45.4 µg mL–1, respectively), better than the positive control butylated hydroxytoluene (BHT) (EC50: 69.34 µg mL–1). For antimicrobial assay, all fractions presented promising minimal inhibitory concentration (MIC). EECLT presented the best values against Staphylococcus aureus (125 µg mL–1) and Escherichia coli (62.5 µg mL–1) and better than the positive control fluconazole (8 and 16 µg mL–1) against Candida albicans (3.9 µg mL–1) and Candida krusei (15.6 µg mL–1) strains. This study presents relevant chemical and biological information about C. lanceloatum expanding the knowledge of Brazilian flora.

Resumo em Inglês:

Methods used to determine pesticide residues in teas typically require several laborious steps for sample preparation before analysis. In this study, a simple method based on solid-liquid extraction with low-temperature partitioning (SLE/LTP) and analysis by gas chromatography coupled to mass spectrometry (GC-MS) was optimized and validated for the determination of pesticide residues (pirimiphos-methyl, flutriafol, cyproconazole, and bifenthrin) in dehydrated green tea leaves. After low-temperature partitioning (LTP), the extract in acetonitrile was subjected to a clean-up step using primary secondary amine (PSA) and octadecylsilane (C18) as sorbents for chlorophyll removal. The optimized SLE/LTP-GC-MS method was validated, and it proved to be effective and selective for extracting pesticides from green tea samples, presenting limit of detection (LOD) and limit of quantification (LOQ) of 0.015 and 0.050 mg kg-1, respectively. Recovery ranged between 81-111%, coefficients of variation were less than 16% and coefficients of determination (R2) were greater than 0.990. The optimized and validated method was applied to green tea and 13 other tea varieties sampled in South and Southeast regions of Brazil. The pesticides under study were detected in some of those samples at values higher than the maximum residue limits (MRLs) allowed by the European Union.

Resumo em Inglês:

A new alkaloid, named brazoide Ε (6), three known steroids (campesterol, β-sitosterol, stigmasterol), two glucosides (3-O-β-D-glucopyranosylsitosterol and 3-O-β-D-glucopyranosyl stigmasterol) and sucrose were isolated from the leaves and stems of Justicia wasshauseniana. Their structures were characterized using high-resolution electrospray ionization mass spectrometry (HRESIMS), nuclear magnetic resonance (1D and 2D NMR), and infrared (IR) spectroscopy. To reinforce the structural proposal, an acetylated derivative (6a) was obtained and its data compared to 6. Moreover, circular dichroism spectroscopy (CD) analysis was performed to determine the absolute stereochemistry, time-dependent density functional theory (TD-DFT) at the wB97X-D/def2-TZVP level, adopting functionals M06-2X and wB97X-D and base aug-cc-pVDZ, was employed to confirm the CD analysis.