Resumo em Inglês:

This study aimed to employ bibliometric methodologies to provide an overview of silver nanoparticles used as antimicrobial agents over the past decade. According to research conducted using the Scopus and Web of Science databases, a total of 2504 articles were published globally, of which 109 were from Brazilian institutions. Notably, approximately 70% of the leading article-producing countries are in Asia, with India emerging as the primary contributor with 1892 articles. Brazil ranked sixth in terms of publication volume, contributing 366 articles. Predominantly, the Southeastern region of Brazil exhibited the highest publication output, constituting 61% of the total, with the state of São Paulo playing a central role. Despite a gradual increase in the number of publications, most studies focused on synthesis methodologies, mainly producing aqueous silver nanoparticle solutions and their correlation with antimicrobial applications. The scarcity of publications addressing their efficacy in final commercialized products poses challenges for regulatory actions, quality control, and sanitary surveillance. Bibliometric studies are valuable tools for guiding future research efforts with significant potential impacts to foster a deeper understanding of this topic within the scientific community.

Resumo em Inglês:

Organic food is produced under specific regulations and must not contain residues from synthetic fertilizers, chemical pesticides, genetically modified organisms, hormones, and antibiotics. Several analytical methods were already been developed to evaluate different organic foods based on separation techniques or elemental analysis, as well as considering molecular spectroscopy. In some cases, chemometric tools were also considered. Research concerning organic food seems to have started in 1980. Until now, this has been a prominent topic of study. Thus, this review proposes a practical guide to verify which analytical techniques and organic food have already been investigated until this moment, which contributes to and facilitates the development of research in this latent topic of study.

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:

The composites of poly (butylene adipate co-terephthalate) / poly (lactic acid) (PBAT/PLA) blend and montmorillonites functionalized using imidazole-derived ionic liquids with different carbon chain sizes (butyl, octyl, and dodecyl) proved to be a promising alternative for improving the thermal and mechanical properties of the polymer blend. Functionalization of montmorillonites by ionic liquids was confirmed by increasing the basal spacing, and spectroscopical and thermal analysis evidence. The composite synthesis was carried out by casting technique generating homogeneous polymeric films. X-ray diffraction analyses suggested that montmorillonite functionalization with the ionic liquid of the butyl carbon chain fostered exfoliation and incorporation of the clay into the polymer. Furthermore, an increase in the thermal stability and mechanical properties of the material was observed. The other composites formed between the PBAT/PLA blend and the montmorillonite functionalized by ionic liquids of higher carbonic chain showed micro composites formation. Thus, their thermal and mechanical properties had no significant improvements.

Resumo em Inglês:

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stands for being the most serious epidemic (so far) of the 21st century. However, only a few computational studies have investigated the molecular mechanisms underlying the neutralization of the spike protein by antibodies of different classes. Hence, bioinformatic methods were employed to unravel the factors contributing to the remarkable neutralization capacity exhibited by specific antibodies. Initially, crystallographic structures of IgA monomeric / dimeric, IgG, and IgM antibodies binding with the receptor-binding domain region of the SARS-CoV-2 spike protein were retrieved. Subsequently, rigid molecular docking and molecular dynamic simulations were performed over 100 ns with explicit water solvation. Lastly, an energy decomposition was conducted to estimate the binding affinity using the last frames from molecular dynamics. The results revealed a higher binding affinity for both monomeric and dimeric forms of IgA antibodies against the spike protein. Additionally, a greater number of hydrogen bonds were observed during their interaction with the spike protein, as well as greater structural instability along the time and especially a more thermodynamically favorable interaction affinity. In this way, the research contributes a small piece to the complex puzzle of understanding the humoral immune response induced by the SARS-CoV-2 virus.

Resumo em Inglês:

Bredemeyera Willd. is a genus of the Polygalaceae family, occurring in Brazil. This research aims to evaluate the phytochemical and antifungal potential, in vitro and in silico, of Bredemeyera brevifolia extracts. The identification of fatty acids by gas chromatography-mass spectrometry and their quantification by gas chromatography-flame ionization detector showed that palmitic (36.55 mg g−1), margaric (3.66 mg g−1), linolelaidic (108.82 mg g−1), oleic (7.86 mg g−1), stearic (41.11 mg g−1), dihomo-γ-linolenic (85.48 mg g−1), and arachidic (209.00 mg g−1) acids are present in the hexane extract. From the chloroform extract, 1-hydroxy-3,7-dimethoxyxanthone was isolated and identified. The minimum inhibitory concentration assay with methanolic extract demonstrated antifungal activity against species of the genus Candida, Sporothrix, and Trichophyton for up to 96 h, with values ranging from 64-1024 μg mL−1. The in silico study with the chemical compounds of this species showed fungal inhibition potential of sterol-14-α-demethylase, highlighting 1-hydroxy-3,7-dimethoxyxanthone, which presented an affinity energy of -8.8 kcal mol−1, greater than that observed for fluconazole (−8.3 kcal mol−1). The fatty acids interacted with the active site of the enzyme but presented energies ≥ −7.4 kcal mol−1. Compounds isolated from this species have pharmacokinetic potential for the development of pharmaceutical formulations.

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.

Resumo em Inglês:

The first step in the synthesis of polyaniline doped with dodecylbenzene sulfonic acid is the synthesis of the anilinium dodecylbenzene sulfonate salt obtained through the reaction between aniline and dodecylbenzene sulfonic acid in aqueous medium. In this work, theoretical models were developed to simulate the formation mechanism of this salt in an aqueous medium. Changes in energy, frontier orbitals, gap energy, charge distribution and thermodynamic parameters were calculated. These theoretical results were correlated with the experimental data from the synthesis of the salt and from infrared spectroscopy. Theoretical models suggested that the solubilization of dodecylbenzene sulfonic acid and aniline in water are energetically and thermodynamically favorable processes. Interactions between the frontier orbitals indicated the formation of water-insoluble anilinium dodecylbenzene sulfonate salt. These molecular modeling results agree with experimental data indicating that the theoretical method used was efficient in simulating the reaction system.

Resumo em Inglês:

Faced with the global challenge of water treatment, the investigation of the removal of endocrine disruptor compounds (EDCs) in aquatic environments is essential to protect human and animals health. In this study, a novel nanocomposite was prepared from biochar from agricultural waste (corn cob) and maghemite (γ-Fe2O3) nanoparticles, named PCCN, to remove four EDCs (triclosan, 17α-ethinylestradiol, methylparaben, and bisphenol A) from aqueous solutions by adsorption. For the characterization of PCCN, the advanced techniques Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), pH of point of zero charge (pHpzc), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetry (TGA) were employed. Competitive adsorption equilibrium studies of EDCs were performed with PCCN and compared to unmodified biochar (PCC). The pH effect showed that optimal adsorption of EDCs was at pH 8.0 for PCC and pH 6.0 for PCCN. The salt concentration did not influence EDCs in the adsorption. In the adsorption isotherm, the results fitted the Freundlich isotherm model (R2 > 0.903) and the adsorption kinetics were well described by the pseudo-second-order model (R2 > 0.985). Furthermore, the desorption studies indicated that the PCCN can be reused. Thus, the investigation suggests PCCN has promising potential in the removal of EDCs from wastewater.

Resumo em Inglês:

Jaboticaba peel powder (JPP) is a residue that contains phenolic compounds, such as anthocyanins and gallic acid. An adsorbent-bioactive complex (ABC) was synthesized using an extract rich in compounds with antioxidant properties obtained from JPP immobilized on microcrystalline cellulose from sweet sorghum bagasse. In this work, the result of thermal degradation of anthocyanins from JPP and ABC, activation energy (Ea), half-life time (t1/2), decimal reduction time (D), temperature variation (Z), thermodynamic parameters (enthalpy (ΔH), Gibbs free energy (ΔG) and entropy (ΔS)) and degradation of antioxidant activities were investigated. Anthocyanin degradation of 35, 60 and 85% was observed for JPP and 10, 30 and 65% for ABC at temperatures of 90-130 °C. Ea of JPP and ABC were 110 and 91 kJ mol-1, respectively. ABC was able to increase from 143-690% the half-life time when compared to JPP. The Z parameter indicated that a greater temperature variation is necessary to degrade ABC anthocyanins (31 °C) when compared to JPP (25 °C). The thermodynamic parameters showed that the energy needed to be broken down to reach the transition state is higher for JPP than ABC, in addition ABC is closer to its thermodynamic equilibrium state. Thus, ABC can be used as an additive in pharmaceutical, cosmetics and food industries, maintaining bioactive and antioxidant properties.

Resumo em Inglês:

This work evaluated the use of corncob as a support for the immobilization of an extracellular fructosyltransferase (E.C. 2.4.1.9) from Aspergillus oryzae IPT-301, aiming at the synthesis of a stable biocatalyst for the production of fructooligosaccharides. The transfructosylation activity of the immobilized enzyme was maximized via experimental design. Additionally, the biochemical properties and stability of the immobilized enzyme, as well as the reaction kinetics, were determined. The enzyme immobilized on alkali-treated corncob showed the highest transfructosylation activity at 50 °C and pH 5.5. It also presented a wide pH stability and a half-life around 1.4 times greater than the soluble enzyme. Furthermore, the immobilized enzyme showed 53% of retention of catalytic activity in a second consecutive reaction cycle, showing the potential for reuse. These results suggest that alkali-treated corncob is a promising support material for the synthesis of heterogeneous biocatalysts aiming at fructooligosaccharide production, which can contribute to the valorization of this abundant agro-waste.

Resumo em Inglês:

Most goods in the world are transported by ships, which are powered by fossil fuels and responsible for atmospheric emissions. This study carries out an evaluation of particulate matter (PM) in the atmosphere of Guanabara Bay, Rio de Janeiro, Brazil. It involves using a MOUDI (Micro-Orifice Uniform Deposit Impactor) cascade impactor, followed by solvent extraction and subsequent chemical analysis by gas chromatography, for the determination of anthracene (ANT), benzo(a)anthracene (BaA), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), chrysene (CRY), fluoranthene (FLT), phenanthrene (PHE) and pyrene (PYR). Samples (57) were collected from October 2019 to January 2021 during 24 h. The average values of coarse particles ranged from 0.46 ng m-3 for FLT to 6.07 ng m-3 for PHE; in fine particles, it was from 0.518 to 4.20 ng m-3 for PHE; no FLT was detected in the ultrafine and the maximum value generated was 4.77 ng m-3 for PHE. FLT was also not detected in the nanoparticles, where the maximum value was 2.43 ng m-3 for PHE.

Resumo em Inglês:

The aim of this work was to develop and characterize nisin-loaded polyethylene oxide (PEO) nanofibers prepared by green electrospinning. The electrospinning operating parameters were optimized and nanofibers with 20,000 and 30,000 IU mL-1 of nisin were obtained. Scanning electron microscopy (SEM) imaging confirmed the formation of uniform, beadless nanofibers with diameters that ranged between 216 and 261 nm. Thermal stability studies showed that the electrospinning process led to the impairment of the crystalline structure of the polymer. Also, Raman spectroscopy tests revealed the interaction between nisin and PEO, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) showed that the addition of nisin did not alter the polymer backbone structure. In addition to this, the X-ray diffraction (XRD) analysis confirmed the semi-crystalline structure of nanofibers. Finally, the resulting nisin-loaded PEO nanofibers were tested against Staphylococcus aureus, confirming its antibacterial activity against this Gram-positive bacteria. Moreover, we also report, apparently for the first time, the antibacterial activity of nisin-loaded PEO nanofibers against Bacillus subtilis. These results expand their applications as green antibacterial biomaterials in areas such as food systems and biomedicine.

Resumo em Inglês:

Evening primrose oil supplements are rich in omega-6 fatty acids, with emphasis on linoleic and γ-linolenic acids, being taken in the treatment and prevention of diseases, but mainly for the relief of symptoms caused by premenstrual tension and menopause in women. This study aimed to evaluate the quality of the lipid profile of evening primrose oil supplements using gas chromatography techniques with a flame ionization detector and mass spectrometry with electrospray ionization. For this, eight commercially available national evening primrose oil brands were used. Of the eight samples analyzed, only two met all the standards established in legislation for fatty acids. The remaining capsules were subjected to triacylglycerol analysis and using a calibration curve the presence of soybean oil in the composition of the evening primrose oil capsules was verified. From the triacylglycerol with a mass/charge ratio of 901, it was possible to identify the addition of 31.16-85.88% of soybean oil in six of the eight capsules, leading the consumer to ingest products that did not comply with current legislation.

Resumo em Inglês:

In this research, the phytochemical study of extracts from the leaves of Siparuna cymosa, an endemic species in Brazil, was carried out for the first time, and evaluated the cytotoxic activity of this extract against leukemia cell lines. The dried leaves were powdered and subjected to extraction by exhaustive maceration with pure organic solvents. The chloroform and ethyl acetate extracts were purified by column chromatography, and the isolated compounds were identified by spectroscopic techniques. The cytotoxic activity of extracts and compounds against THP-1 (acute myeloid) and K-562 (chronic myeloid) leukemia lines was determined using 3-(4,5-dimethyl-2-thyazolyl)-2,5-diphenyl-tetrazoliumbromide (MTT) assay. The isolated compounds were 1,5,6-trimethyl-8 oxabicyclo[3.2.1]oct-6-en-3-ol, β-sitosterol-3-O-β-D-glucopyranoside, and kaempferol-3,7 di-O-α-L-rhamnoside. This is the first report of isolation of oxabicyclo-octenol in plant species. β-Sitosterol-3-O-β-D-glucopyranoside and kaempferol-3,7-di-O-α-L-rhamnoside significantly reduced the viability of tumor cells after controlled exposure for 48 h. Moreover, selectivity was at least two times higher for such lineages compared to the results found for non-tumor peripheral blood cells (PBMC). Kaempferol-3,7-di-O-α-L-rhamnoside was the most active and selective. In conclusion, metabolites from S. cymosa showed to be of scientific interest. This study shows that the biodiversity of plant species in Brazil represents an important arsenal of organic compounds and, therefore, research should be motivated aiming at the isolation of secondary metabolites.

Resumo em Inglês:

Antibiotic resistance raises concerns about their residues in food and the environment. To produce antibiotic-free dairy products, countries explore new strategies to reduce antibiotic doses in mastitis treatment. Lactoferrins (LF), iron-binding glycoproteins, exhibit species-specific glycosylation affecting their properties. While formulations of bovine lactoferrin have been tested with antibiotics showed synergistic properties increasing the antibacterial properties, other interactions of lactoferrin isoforms with antibiotics remain unclear. This study isolates, purifies, and characterizes buffalo lactoferrin (Bf-LF) and its interaction with amoxicillin. Bf-LF was purified using a Sephacryl S-100 column and monitored spectrofluorometrically. Spectroscopic analysis of Bf-LF interaction with amoxicillin reveals that increasing amoxicillin concentration reduces Bf LF fluorescence, indicating conformational changes. The Stern-Volmer quenching constant (KSV) and binding constant (Ka) measured at 298 K shows values around (2.79 ± 0.29) × 104 L mol-1 and (0.300 ± 0.04) × 104 L mol-1, respectively. UV-Vis spectroscopy shows a red shift (258.08 to 271.83 nm) implying Bf-LF-amoxicillin binding. In silico studies suggest polar interactions between amoxicillin and specific Bf-LF amino acids.

Resumo em Inglês:

This work evaluated the elemental content and toxicology of the primary materials of the e-liquids without adding nicotine and other additives. Elemental content was determined through inductively coupled plasma mass spectrometry (ICP-MS) analyses, and biological effects were evaluated in Saccharomyces cerevisiae and H9c2 cells. Elemental analysis did not detect toxic elements above the limit of quantification (LOQ). Toxic concentration with significant difference (p < 0.05) between the samples and the non-exposed cells for glycerin (7.5% m/v) and propylene glycol (12.5% m/v) and at 70/30 proportions (12.5% m/v), 50/50 (12.5% m/v), and 30/70 (6.25% m/v) were encountered. Yeast toxicity presented a concentration-dependent relation with growth inhibition and lethality. Cytotoxicity tests in mammalian cells presented significant differences (p < 0.05) at low concentrations of glycerin and propylene glycol exposition (1.25 and 0.25% m/v, respectively). High concentrations of glycerin and propylene glycol induced increased reactive oxygen species/lactate dehydrogenase, decreased catalase activity, and interference in cell viability. On acute exposure, pure glycerin and propylene glycol are toxic for yeast and H9c2 cells, increasing with proportions of glycerin/propylene glycol and the increased amount of propylene glycol in the solution. No correlation between elemental content and toxicity was observed.