Resumo em Inglês:

An unprecedented alkylresorcinol glucoside, named citrifolin A, was isolated from the leaves of Eugenia citrifolia Poir. (Myrtaceae). Its structure was elucidated by nuclear magnetic resonance (NMR) spectroscopy in combination with high-resolution mass spectrometry (HRMS), and its absolute configuration was established by electronic circular dichroism (ECD) spectroscopy supported by density functional theory (DFT) calculations. The antioxidant potential of citrifolin A was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free-radical scavenging assays, in which the compound exhibited low activity.

Resumo em Inglês:

The risk of vertical transmission of the human immunodeficiency virus (HIV), the major concern among pregnant women living with the virus, can be reduced through early diagnosis and initiation of antiretroviral therapy (ART). Although conventional tests used for HIV diagnosis are effective, they are labor-intensive and costly, highlighting the need for faster and more accessible methods. In this study, fluorescence spectroscopy in excitation-emission matrix (EEM) combined with multiway analysis techniques was employed as an alternative approach to diagnose HIV in blood plasma samples from 26 uninfected and 26 pregnant women living with HIV. The Tucker3 QDA (Tucker3-quadratic discriminant analysis) and n-PLS-DA (n-way partial least squares discriminant analysis) classification algorithms were applied, and their performances were assessed based on figures of merit: accuracy, sensitivity, specificity, F-score, and G-score The n-PLS-DA model achieved the best classification performance, with 81.25% accuracy, 87.50% sensitivity, 75.00% specificity, 80.77% F-score, and 81.07% G-score. These results demonstrate the potential of the proposed method as a rapid, simple, and low-cost alternative for HIV screening during pregnancy.

Resumo em Inglês:

N-Bromosuccinimide (NBS) is a versatile brominating reagent. It is used not only in radical bromination but also in electrophilic addition and electrophilic substitution reactions. NBS can be used to obtain aryl bromides, which are useful for further functionalization, such as coupling reactions for C/N/O/S-aryl bond formation. However, the succinimide group of NBS is poorly explored and is often treated as a waste. In this work, it is proposed the full use of NBS, both for bromination of arenes and for the incorporation of the succinimide group in a one-pot fashion. Using low-cost reagents such as Cu2O and K3PO4, N-arylsuccinimides were obtained in moderate to good yields directly from non-halogenated aromatics. It was observed that microwave irradiation was crucial to circumvent the low nucleophilicity of succinimide.

Resumo em Inglês:

The growing demand for natural ingredients and environmentally responsible solutions has driven the use of bioactive compounds obtained from unconventional edible sources in the formulation of sustainable packaging. Phenolic compounds, flavonoids, and other natural metabolites are widely recognized for their properties of delaying lipid oxidation, reducing microbial proliferation, and minimizing food spoilage processes. In this context, this study aimed to review the use of bioactive compounds from unconventional natural sources, adding them as an innovative and sustainable alternative for the food industry. The study also highlights the main valued bioactive compounds, methods for evaluating antioxidant activity, strategies for incorporating these compounds into active films, and their overall contributions to sustainability. Unconventional edible sources, including underutilized species and agro-industrial by-products, present high levels of natural antioxidants, contributing to the valorization of waste and the construction of more sustainable production chains. When incorporated into polymer matrices, these compounds enable the development of active packaging capable of releasing protective substances in a controlled manner and improving food stability. This approach strengthens the integration between materials science, food chemistry, and technological innovation, highlighting the potential of these natural sources to replace petroleum-derived polymers. The adoption of these alternatives favors practices aligned with the circular economy, promotes consumer health, and adds value to traditionally underutilized materials. Thus, this review highlights the relevance of active compounds from unconventional edible sources for the development of biodegradable packaging, reinforcing their environmental, functional, and technological importance.

Resumo em Inglês:

The synthesis of sulfur-linked glycosides, such as S-glycosides or S-glycoconjugates, has been extensively explored due to their roles as valuable tools in various biological studies. These compounds can act as glycosidase inhibitors, antibacterial agents, antitumor agents, and more. 1-Thioglycosides are characterized by a sulfur atom bonded to the anomeric position and are rare in nature. Besides their biological and pharmaceutical significance, thioglycosides serve as key substrates for the synthesis of other glycosides (O-, N-, and C-glycosides), glycoconjugates, glycoproteins, and polysaccharides. The growing interest in biologically active S-glycosides stems from their enhanced stability compared to O-glycosides, making them less prone to enzymatic hydrolysis and chemical degradation. This stability underpins their use as enzyme inhibitors and their presence in various drugs and bioactive natural products. Consequently, the development of efficient synthetic methodologies for functionalized 1-thioglycosides remains a critical focus in medicinal and organic chemistry research. This review focuses on recent advances in the synthetic methodologies for functionalized 1-thioglycosides, highlighting key strategies and their potential applications in medicinal chemistry.

Resumo em Inglês:

In 2025, the U.S. Food and Drug Administration (FDA) approved 46 new drugs comprising 31 small-molecule entities. These approvals represent significant milestones in the evolution of privileged structures and novel mechanisms of action, serving as invaluable leads for the development of next-generation therapeutics with enhanced efficacy. This article reviews the synthetic routes and clinical indications of these newly marketed drugs, highlighting their significance in the current pharmaceutical landscape.

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This study reports the development of a novel high-throughput solid-phase extraction (SPE) method using a hybrid bifunctional organic-inorganic molecularly imprinted polymer (BHMIP) for the selective preconcentration of diuron in environmental waters and soymilk. The BHMIP was synthesized with methacrylic acid and phenyltrimethoxysilane as organic and inorganic monomers. The method involves preconcentration of 50.0 mL of sample through 150.0 mg of BHMIP at a high flow rate (14.0 mL min-1), followed by elution with 6.0 mL of methanol and analysis by high-performance liquid chromatography with diode array detector (HPLC-DAD). It showed excellent linearity (0.27-200.0 μg L-1, coefficient of determination (R2) = 0.999), with limits of detection and quantification of 0.08 and 0.27 μg L-1, respectively. A high preconcentration factor of 173-fold was achieved. The method was successfully applied to surface water and soymilk samples, with recovery rates of 92-104% and 93-110%, confirming negligible matrix effects. Precision assays yielded relative standard deviations of 3.16-4.07% at two concentration levels. The BHMIP demonstrated efficient clean-up of complex matrices without loss of extraction efficiency, enabling sensitive detection of diuron at trace levels. This validates the method as a robust, selective, and reliable tool for monitoring diuron residues in environmental and food samples.

Resumo em Inglês:

Kraft lignin (KL), a major byproduct of the pulp and paper industry, is still largely under-utilized, limiting its value in advanced materials. This work investigates whether incorporating carbonized kraft lignin (CKL) into polyvinyl alcohol (PVA) films can enhance their structural and functional properties and enable their use as gas-sensor membranes. PVA films containing 0, 10, 30, and 50 weight percent (wt.%) CKL were prepared and characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), water-contact-angle (wettability) measurements, and tensile testing, followed by ammonia (NH3), ethanol (C2H5OH), and toluene (C7H8) sensing. CKL increased thermal stability (temperature at 5% mass loss, T5%, up to 135 °C vs. 80 °C for neat PVA), raised carbonaceous residue to 15%, and improved Young’s modulus while reducing elongation and water contact angle. Gas-sensing tests revealed a strong, reversible current response to NH3, with PVA/50 wt.% CKL exhibiting the highest current (ca. 23 µA), along with detectable responses to ethanol and toluene. These results demonstrate that CKL is an effective bio-derived additive that upgrades PVA films for sustainable, high-performance gas-sensing applications.

Resumo em Inglês:

Iron and manganese are important water quality parameters, as their presence can lead to undesirable color and odor. Here, hydrochars (HCs) were synthesized from banana peels via hydrothermal carbonization to produce a sustainable adsorbent for efficient iron and manganese removal from water. A 23 factorial design with a central point was carried out to evaluate the variables: (i) activating agent (H3PO4 or NaOH), (ii) temperature (100 and 200 °C), and (iii) residence time (8 and 14 h). HC9 was performed in water at 150 °C for 11 h. Optimal performance was evaluated from Fe2+ and Mn2+ removal. Fourier transform infrared (FTIR) confirmed functional groups in all HCs, while X-ray diffraction (XRD) broad peaks between 15-30° indicated an amorphous structure. HC9 showed the best performance for the adsorption of both metals. Equilibrium was reached at 200 min, and the kinetic data were best described by the pseudo-second-order model. The adsorption data were best fitted by the Langmuir model for Fe and the Freundlich model for Mn, with maximum adsorption capacities (qmax) values of 33.18 and 19.00 mg g⁻1 for Fe and Mn, respectively. Thus, adsorption using this biochar is a promising and environmentally friendly method for removing those metals from aqueous systems.

Resumo em Inglês:

Natural rubber (NR) latex from Hevea brasiliensis can be modified with functional particles to obtain advanced materials. This study evaluates the biocompatibility of two NR-based hybrid systems incorporating calcium phosphate (CaP) and silica (SiP) particles for medical and industrial use. Films (NRHS) were prepared using chloroform (CHF) and toluene (TOL) as solvents, and their physicochemical surface properties and interactions with osteoblastic cells were analyzed. Parameters included morphology, alkaline phosphatase (ALP) activity, and cell viability ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay). Hybridization altered surface energy and wettability, key factors for biocompatibility. Depending on solvent and particle combinations, NRHS modulated osteoblast responses, either preserving, impairing, or enhancing proliferation and enzymatic activity. Both NR-CaP and NR-SiP composites influenced surface energy and contact angle, while generally maintaining viability. These results highlight the tunability of NRHS via particle incorporation, and their positive cellular interactions suggest strong potential for biosensing and biomedical device engineering.

Resumo em Inglês:

Volatile terpene profiles are central to plant-insect interactions, but their characterization is critically dependent on extraction methodology. This study evaluates how extraction techniques (hydrodistillation vs. headspace) and leaf hydration states (fresh, dried, rehydrated) alter the volatile terpene profile of a Mikania sp., with a focus on the implications for chemical ecology. Gas chromatography-mass spectrometry (GC-MS/MS) analysis revealed stark methodological divergences: hydrodistillation amplified sesquiterpenes (14.34% of total terpenes), including potential thermal artifacts like trans-muurola-4(14),5-diene (4.72% in essential oil (EO) vs. < 0.83% in headspace), while headspace methods captured hydration-sensitive monoterpenes. Rehydrated leaves emitted an exclusive monoterpene profile (100%), dominated by p-cymene (26.4%), and drying shifted profiles toward sesquiterpenes (13.34% in dried leaves vs. 5.59% in fresh). Multivariate analysis confirmed strong method-specific clustering, with hydrodistillation and headspace sharing only a core set of compounds, specifically monoterpenes. These findings highlight that extraction protocols actively shape the chemical landscape, and that using multiple complementary techniques is essential in insect-plant chemical ecology to capture natural emissions accurately and distinguish genuine ecological signals from methodological artifacts.

Resumo em Inglês:

Bisphenol A (BPA) is an endocrine-disrupting chemical used in polycarbonate plastics, epoxy resins, and thermal paper, and has been linked to health problems. Human exposure occurs mainly through ingestion and dermal contact, and BPA is detected in various biological and environmental matrices. This study quantified and evaluated BPA in urine, drinking water, and thermal paper samples collected from commercial establishments in southern Brazil. The analytical method applied was liquid chromatography coupled to mass spectrometry (LC-MS/MS). BPA was detected in 100% of urine samples, with concentrations ranging from 0.11 to 63.69 ng mL-1, indicating continuous exposure. In drinking water, concentrations varied from < 0.04 to 21.66 ng L-1, remaining within European Union regulatory limits. In contrast, 15% of thermal paper samples showed BPA above the permitted limit, with values ranging from 5,035.9 to 24,218.8 ng mg-1. Toxicological risk assessment indicated that, under previously established intake limits, exposure through drinking water and thermal paper would be considered safe. However, with the new tolerable daily intake (TDI) set by the European Food Safety Agency (EFSA) in 2023 (0.2 ng kg-1 body weight per day), exposure became a concern for a significant part of the study population. These findings highlight potential health risks and regulatory gaps in Brazil, emphasizing the need for stricter measures and safer alternatives to BPA in consumer products. They also reinforce the importance of monitoring BPA exposure and aligning national regulations with international safety standards.

Resumo em Inglês:

The growing threat of antimicrobial resistance has intensified the search for new antimicrobial materials. In this work, zinc bismuthate-based nanocomposites (ZB1 and ZB4) were synthesized by a hydrothermal method and characterized using X-ray diffraction, Raman spectroscopy, zeta potential and high-resolution transmission electron microscopy. Structural analyses suggested the coexistence of a zinc oxide secondary phase and oxygen vacancies, which may influence the physicochemical and biological behavior of the materials. The antimicrobial activity was evaluated against Staphylococcus aureus, Corynebacterium diphtheriae, Klebsiella pneumoniae, Cryptococcus neoformans, and Candida albicans by disk diffusion. For C. diphtheriae and C. neoformans, additional minimum inhibitory concentration and minimum fungicidal concentration assays were performed. Both nanocomposites inhibited S. aureus, C. diphtheriae, and C. neoformans, while no inhibition was observed for C. albicans and K. pneumoniae. ZB4 exhibited superior antimicrobial activity, with growth inhibition observed up to 500 µg mL-1, whereas ZB1 was effective only at higher concentrations. Toxicity tests using Tenebrio molitor larvae revealed survival rates of approximately 70% for ZB1 and 60% for ZB4 after 10 days, with no statistically significant difference compared to the control. Overall, ZB4 presented promising antimicrobial activity with moderate toxicity, indicating its potential for biomedical applications.

Resumo em Inglês:

This work investigates the potential of Eu3+ and Eu3+-Mn2+ doped metal-organic frameworks (MOFs) of the MOF-5 type as a temperature sensor (298-393 K). The MOF-5 were synthesized via reflux and characterized using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and spectroscopic techniques. The emission spectra of the MOFs were obtained in response to temperature variations to define the thermometric configurations and sensor performance. The MOF-5 containing only Eu3+ showed low thermal sensitivity in the temperature range between 298-393 K, with a maximum sensitivity of 0.12% K-1. In turn, the addition of Mn2+ to MOF-5 (MnEu-MOF-5) was examined in a specific increase in thermal sensitivity close to 8% K-1 estimated at the temperature of 303 K. Computational calculations were important for the structural elucidation of MOF-5 with Eu3+ and understanding the energy transfer processes involved. The results show that the incorporation of Mn2+ into EuMOF-5 may be a promising candidate for application as a luminescent thermometer, since it presented high sensitivity for temperature measurement close to 303 K.

Resumo em Inglês:

Cigarette smuggling and counterfeiting undermine public health and border security. Conventional analytical methods are expensive, non-specific and often ignore multicollinearity and robust validation. No current supervised multiclass model meets forensic laboratory needs for simplicity and scalability. In this context, this study proposed a cheaper and faster novel chemometric method to confirm the origin of cigarette brands marketed in Brazil. The method employs ultrasonic extraction using dichloromethane followed by gas chromatography coupled to flame ionization detection (GC FID), and full chromatographic fingerprints (peak areas and retention times) aligned with the R package GCalignR. This method developed can captures and exploits a larger number of chromatographic peaks, thereby providing greater chemical information per sample than conventional targeted analytical approaches. The aligned data were used in a Hierarchical Cluster Analysis (HCA) for exploratory grouping and in a Linear Discriminant Analysis (LDA) for supervised classification. Model validation employed train/test partitioning and a one vs one receiver operating characteristic (ROC) analysis, yielding area under the curve (AUCs) > 0.95 for all classes and cross validated accuracy > 90%. The workflow requires under 15 min of sample preparation per batch and can be automated for high throughput screening in standard analytical laboratories. The method validation results demonstrated high sensitivity, accuracy, and AUC confirming the robustness of the model and strong potential for use as a practical, predictive, and scalable forensic screening tool in regulatory and enforcement settings. This cost effective, quick and predictive method fills a critical gap, providing agencies with a robust workflow that is both operationally practical and easily integrated into routine analytical environments.

Resumo em Inglês:

The Euphorbiaceae family is well recognized for its chemical diversity, particularly in terpenoid metabolites, while species of the genus Sapium are traditionally used in folk medicine but remain scarcely explored chemically. The phytochemical investigation of the roots of Sapium glandulosum afforded sapientrione (1), a nor-triterpene with an unprecedented carbon skeleton, featuring a seven membered ring fused to C-26. The compound was purified by chromatographic techniques and its structure was fully elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy associated with high-resolution electrospray ionization-mass spectrometry (HRESIMS) and supported by infrared and UV data. A plausible biosynthetic pathway from the multifloryl cation is proposed. Preliminary assays indicated moderate antimycobacterial activity without cytotoxicity. The discovery of sapientrione expands the structural diversity of triterpenoids and reinforces the phytochemical potential of Sapium species as a source of novel natural products.

Resumo em Inglês:

This study employed an integrated untargeted metabolomics approach to identify resistance-associated biomarkers in dwarf cashew (Anacardium occidentale L.) genotypes under black mold stress-a severe foliar disease caused by Pilgeriella anacardii Arx & Müller. Metabolomic profiling was performed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MSE) and nuclear magnetic resonance (NMR) spectroscopy. This methodology enabled a comprehensive analysis of four dwarf cashew genotypes with varying resistance to P. anacardii: ‘CCP 76’ and ‘BRS 189’ were susceptible, ‘BRS 226’ was intermediate, and ‘BRS 265’ was resistant. Orthogonal partial least squares discriminant analysis (OPLS-DA) revealed clear metabolic segregation between resistant, susceptible, and intermediate genotypes, with high predictive power (R2Y ≥ 0.98; Q2 ≥ 0.95). Resistant clones (BRS 265 and BRS 226) showed pronounced metabolic reprogramming, marked by increased accumulation of flavonoid glycosides (quercetin-3-D-glucoside, isoquercetin), flavan-3-ols ((+)-catechin, gallocatechin), galloylated glucose derivatives (pentaand tetra-O-galloyl-glucosides), and biflavonoids (amentoflavone, agathisflavone). These compounds function as antioxidants, membrane disruptors, metal chelators, enzyme inhibitors, and immune response modulators. Pathway enrichment analysis highlighted the activation of flavonoid and flavonol biosynthesis as central to resistance. Elevated sucrose levels in resistant genotypes suggest a role in energy supply and systemic signaling. Altogether, this metabolomic fingerprint supports a complex biochemical defense strategy and offers robust biomarkers for marker-assisted selection.

Resumo em Inglês:

The chocolate and cosmetics industries are interested in cocoa varieties that yield high levels of cocoa butter with low acidity, a high melting point, and thermal stability. This study aims to analyze how different cocoa varieties influence the fatty acid composition, thermal properties, and physicochemical characteristics of cocoa butter. Three cocoa varieties (BN34, CCN51, PS1319) that had already been fermented and dried were roasted, and peeled before undergoing mechanical pressure to extract cocoa butter. The fat content was then calculated. Analyses were conducted, including the almond cutting test, density measurements, fatty acid composition analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (DTA/DTG), physicochemical property assessment, and mid-infrared spectroscopy (MIR) of the butter samples. The BN34 and CCN51 cocoa varieties have a higher fat content than PS1319, but PS1319 has a higher melting point and greater thermal stability, despite having a similar fatty acid composition. Physical-chemical analyses reveal significant differences in moisture and acidity, with BN34 showing the lowest values. Acidity and refractive indices met quality standards, and MIR spectra demonstrate similar profiles among varieties. Thus, PS1319 is better suited for the chocolate industry, while the BN34 and CCN51 varieties are more appropriate for applications that prioritize a high cocoa butter yield.

Resumo em Inglês:

The correct reproduction of key vibrational circular dichroism (VCD) spectral features of furofuran lignans commonly requires the inclusion of explicit acetonitrile solvation in density functional theory calculations. This requirement, however, seems to be neither universal nor restricted to acetonitrile. In order to better understand the conformational stabilization promoted by different solvents, and consequently its effect on VCD spectra, herein, we report experimental and computational VCD investigations of kobusin, sesamin, and episesamin in acetonitrile and chloroform solutions. These molecules differ from previously reported furofuran lignans in their aromatic ring substitution, symmetry, flexibility, and H-bonding affinity. The simulation of explicit solvation using molecular dynamics combined with hybrid quantum mechanics/molecular mechanics calculations was found to be critical for the correct reproduction of VCD patterns in kobusin and sesamin in acetonitrile, whereas the VCD spectrum of episesamin was satisfactorily simulated using implicit solvation. For sesamin, simulations of explicit chloroform were also performed, leading once again to a better correlation with experiment. These results indicate that explicit solvation becomes necessary for VCD simulations as molecular symmetry and flexibility increase, which affects both conformation and vibrational coupling. Finally, some VCD spectral markers are proposed for the assignment of both relative and absolute configurations of furofuran lignans.

Resumo em Inglês:

The accumulation of advanced glycation end products (AGEs) contributes to various chronic diseases. In this study, using a lactose (Lac)-induced glycation model of β-lactoglobulin (BLG), we investigated the inhibitory effects of curcumin (CUR), demethoxycurcumin (DMC), and tetrahydrocurcumin (THC) on AGEs formation, with efficacy following the order: CUR > DMC > THC. Spectroscopic and microscopic techniques confirmed their ability to prevent glycation-induced conformational changes and aggregation of BLG. Fluorescence spectroscopy, molecular docking, and radical scavenging assays indicated a potential mechanism that might involve the occupation of glycation sites (Lysine 60 (Lys60) and Lysine 69 (Lys69)) of BLG, with inhibitory potency correlating with their binding affinity. Molecular dynamics (MD) simulations confirmed the structural stability of the complexes formed between BLG and the three curcuminoids. Furthermore, intracellular reactive oxygen species (ROS) assays showed that they not only alleviate cellular oxidative stress by inhibiting the production of AGEs, but also mitigate AGEs-induced cellular oxidative damage. These findings elucidate how minute structural differences among the three curcuminoids influence their ability to inhibit AGEs formation, suggesting potential mechanisms for their suppression of BLG glycation, providing a theoretical basis for developing natural anti-glycation agents.

Resumo em Inglês:

Differencing citrus essential oils was achieved by excitation-emission matrix fluorescence spectroscopy using hydro-alcoholic systems with low sample content. Studies were employed to assess the optimal conditions, aiming to encompass all evaluated citrus essential oils (sweet and sour orange, grapefruit, lemon, and tangerine) without compromising measurement reproducibility. In addition to low sample consumption, a significant increase in fluorescence was achieved, which can be explained by the formation of weak micelle-like aggregates in surfactant-free microemulsions. To demonstrate the potential of the proposed method for discriminating samples, fluorescence excitation-emission matrix data were utilized for clustering analysis. Unfolded principal component analysis was successfully applied, with a cumulative variance of 99.5% based on three principal components. Complementary analyses by liquid chromatography were conducted to confirm the relationship between fluorophores and the non-volatile fraction, characteristic of citrus essential oils. The combination of low sample consumption and high-water content makes the application of these systems advantageous for essential oil monitoring also attending requirements for a greener analytical method, as confirmed by an Analytical Eco-Scale score of 85.

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Corticosteroids are widely prescribed to treat inflammatory conditions. Understanding their thermal stability is essential to ensure their safety and efficacy during storage, processing, and pharmaceutical use. This study investigated the non-isothermal decomposition kinetics of prednisone, betamethasone valerate, and hydrocortisone acetate using thermogravimetric analysis. Vyazovkin Isoconversional Method was employed to evaluate the activation energy profiles, followed by kinetic model fitting to determine the pre-exponential factors. A multilayer perceptron neural network was implemented to identify the most suitable reaction mechanisms and complete the kinetic triplet for the reaction. Thermal analysis revealed three decomposition events for prednisone and betamethasone valerate and two events for hydrocortisone acetate, reflecting the influence of structural differences on their stability. The neural network provided more accurate predictions than the single kinetic models and indicated that most decomposition steps followed the Avrami-Erofeev model. In this context, nucleation and growth are interpreted as the stochastic initiation and propagation of reactive nuclei through molecular rearrangements and diffusion in the amorphous or liquid phases, rather than crystallization phenomena. Although originally developed for isothermal conditions, the Avrami-Erofeev approach has been widely and successfully applied to dynamic heating experiments as a phenomenological model for describing decomposition kinetics. These results provide unprecedented insights into corticosteroid stability, contributing to preformulation, quality control, and pharmaceutical development.

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Many efforts have been put into improving the color strength of polyamide (PA) 66. In this study, Color Index (C.I.) Acid Blue 90, a kind of triphenylmethane dye with a large conjugated structure and high molecular weight, was used to dye PA 66 fibers. The response surface method (RSM) was used to determine the optimum dyeing conditions, and the results verified its effectiveness. A color strength (K/S value) of 37.1 can be achieved, which is among the highest K/S values on PA 66, when using 4% on weight of fabric (o.w.f.) dyestuff at the optimized technological parameters. Further studies on adsorption kinetics revealed a pseudo-second-order model was more accurate, and the half-dyeing time was only 1.02 min. The diffusion coefficient of C.I. Acid Blue 90 on PA 66 increased with the rise of temperature, and was mainly in the range of (3 15) × 10-13 m2 min-1. The dyeing affinity is 815.2, 2861.6 and 5877.8 J mol-1 at 80, 90, and 100 °C, respectively. These results provide a theoretical basis for understanding the processes and mechanisms of nylon dyeing using dyestuffs with large conjugated structures and high molecular weights.

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In order to investigate the influence of substrate and additive on Bi2-xSbxTe3 thermoelectric films, Bi2-xSbxTe3 films were successfully fabricated on the surface of indium-tin-oxide (ITO) and stainless steel (SS) in HNO3 solution using constant potential technique. Meanwhile, Bi2-xSbxTe3 film was prepared on ITO substrate using the electrolyte containing thiourea as an additive. The phases of the annealed thin films were determined by X-ray diffraction (XRD). Besides, the morphologies of the annealed films were characterized by scanning electron microscopy (SEM), and the property parameters of Bi2-xSbxTe3 thermoelectric films were also tested. The results showed that the as fabricated thin films on ITO in electrolyte with or without thiourea and SS substrates were pure (Bi0.5Sb0.5)4Te3. Moreover, the films prepared on ITO or SS substrate had a granular structure, but the surface morphologies were quite different. The (Bi0.5Sb0.5)4Te3 film electrodeposited on ITO in electrolyte without additive presented walnut seed-like morphology, while the annealed film electrodeposited in electrolyte with additive presented rose-like morphology. However, the (Bi0.5Sb0.5)4Te3 film electrodeposited on SS presented cotton-like morphology. In addition, the annealed film electrodeposited on ITO in electrode with additive was denser; thereby, it has the highest electrical conductivity of 984.50 S cm-1 compared with the other two films.

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Acetylsalicylic acid (ASA) is a persistent pharmaceutical contaminant whose low biodegradability demands more efficient treatment alternatives. This study compares conventional electrocoagulation (EC-Conv) and photovoltaic-powered electrocoagulation (PV-EC) for ASA removal under identical operational conditions. PV-EC achieved higher and more stable removal efficiencies (78-85%) than EC-Conv (65-75%), maintaining zeta potential (ζ) within the optimal range for colloidal destabilization (-1.0 to -2.0 mV) and promoting the formation of macroflocs (> 10,000 nm). Response-surface analysis confirmed that slightly negative ζ values enhance particle aggregation, whereas values near 0 mV reduce process efficiency. Operational indicators showed clear advantages for PV-EC, including lower energy consumption (≤ 1.3 vs. 5.5 kWh m-3), reduced electrode dissolution (≤ 0.04 vs. 0.16 kg m-3), and substantially lower operating costs (≤ 0.73 vs. 3.13 R$ m-3). Overall, the results demonstrate that solar-powered electrocoagulation is a more efficient, economical, and sustainable alternative for ASA removal, reinforcing its potential for decentralized and large-scale applications in the treatment of pharmaceutical contaminants.

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The demand for porous sodium super ionic conductor (NASICON)-type materials with high surface area and controlled microstructure has intensified due to their potential in energy storage, sensing, and catalytic applications. However, conventional synthesis routes are often complex and poorly scalable. Here, we demonstrate that acid leaching of lithium germanophosphate-based glass-ceramics provides an efficient pathway for NASICON phase formation while enabling selective dissolution of soluble phases. The effects of acid type (hydrochloric acid (HCl) and phosphoric acid (H3PO4), 1 mol L-1) and leaching temperature (25 and 70 °C) on the phase purity, morphology, and porosity of NASICON monoliths derived from 6Li2O-24GeO2-39CaO-31P2O5 (mol%) glasses heat-treated at 658 and 750 °C were systematically investigated. Leaching in H3PO4 at 25 °C produced monoliths with high structural integrity, large interconnected pores (ca. 10 µm), and selective NASICON preservation, attributed to the phosphate-assisted removal of metaphosphate and pyrophosphate species. In contrast, HCl leaching at 25 °C generated smaller pores (ca. 1 µm) with germanium dioxide (GeO2) residues, while higher temperatures (70 °C) in either acid completely dissolved the NASICON phase. These results establish a rational framework for tuning the morphology and phase purity of porous NASICON glass-ceramics via coupled thermal and chemical processing, offering new insights for their targeted design in energy, catalytic, and sensing technologies.

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Whey, a high-volume by-product of the dairy industry, is a valuable substrate for biotechnological valorization that presents an environmental challenge. This study aimed to investigate the kinetic and rheological behavior of Kluyveromyces marxianus during lactic acid fermentation using deproteinized whey by varying initial lactose (35 and 50 g L-1) and inoculum (3 × 106 and 10 × 106 cells mL-1) concentrations and working volumes (0.6 and 0.9 L), through a full factorial (23) experimental design. Growth kinetics, lactose consumption, and lactic acid production were modeled using the Gompertz, Luedeking-Piret, and Pirt models. Rheological behavior was obtained using the Ostwald-de Waele power-law model. A rheokinetic model that integrates biomass growth with fluid properties was proposed. The results showed that high lactose and low inoculum levels significantly improved lactic acid yield (0.285 g g-1) and productivity (0.116 g L-1 h-1). Strong statistical interactions were identified between inoculum and substrate levels. The rheokinetic model demonstrated strong correlations between the consistency coefficient and the rheological behavior index, as well as microbial growth (correlation coefficient (R2) > 0.92), providing a predictive tool that eliminates the need for destructive measurements.

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This study investigates the performance of lipase B from Candida antarctica (CALB) immobilized on magnetic Fe3O4 nanoparticles (MNs) for the enantioselective esterification of racemic ibuprofen. The nanoparticles were synthesized by co-precipitation and subsequently functionalized with γ-aminopropyltriethoxysilane (APTS) and glutaraldehyde (GLU) to provide reactive aldehyde groups for enzyme attachment. CALB was covalently immobilized onto the activated support, and the resulting biocatalyst was characterized by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR), confirming successful functionalization and enzyme immobilization. The effects of stirring speed (20-250 rpm), enzyme loading (50 650 U p-nitrophenyl butyrate (p-NPB) g-1), contact time (0.5-5 h), glutaraldehyde concentration (2.5-25%), and sodium dodecyl sulfate (SDS, 0.23%) addition were systematically evaluated. The optimal immobilization conditions (45 rpm, 25 °C, pH 7.0, and 1 h of contact with an enzyme load of 80 U p-NPB g-1) yielded an immobilization efficiency of 53% and an immobilized enzyme activity of 29.1 U g-1. The MNs-CALB derivative exhibited excellent thermal stability (20-fold higher half-life than the soluble enzyme) and was successfully applied in the esterification of racemic ibuprofen with 1-propanol in cyclohexane, preferentially producing the (R)-(-)-ibuprofen propyl ester. Molecular docking simulations supported these results by demonstrating favorable interactions between the (R)-enantiomer and CALB’s catalytic triad (Ser105-His224-Asp187). These findings highlight the potential of magnetically recoverable nanobiocatalysts as efficient, stable, and enantioselective systems for green and sustainable synthesis of chiral pharmaceuticals.

Resumo em Inglês:

Araçá (Psidium guineense Sw.) fruits were collected in Belém and freeze-dried for 72 h. An ultrasound-assisted extraction method was optimized using a central composite design (23) to evaluate the effects of ethanol concentration, solid-liquid ratio (SLR), and extraction time on total phenolics content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) percentage of radical inhibition). A predictive polynomial model established at a 95% confidence level indicated optimal parameters of 25% ethanol, a 1:5 SLR, and a 10 min extraction time, yielding 304.6 ± 7.7 mg gallic acid equivalent (GAE) g-1 of TPC and 59.5 ± 1.7% DPPH inhibition. The optimized extract also inhibited β-carotene lipid peroxidation with an IC50 value (half maximal inhibitory concentration) of 20.9 µg mL-1 and presented a sun protection factor of 16.0 ± 1.0. It contained substantial amounts of total flavonoids and carotenoids: 309.2 ± 17.7 mg quercetin equivalent (QE) g-1 and 108.2 ± 11.1 µg g-1, respectively. Liquid chromatography-electrospray ionization ion trap mass spectrometry (LC-MS/MS) analysis annotated key bioactive compounds, including quinic acid, ellagic acid, valoneic acid dilactone, and caffeoyl-quinic acid, these compounds are responsible for the antioxidant potential. Additionally, the extract demonstrated a bactericidal effect against Staphylococcus aureus, highlighting its potential use as an antiseptic. The bioprospecting of extract supports the potential for new industrial applications of P. guineense fruits, particularly within the cosmetic sector.

Resumo em Inglês:

In this work, the trans[Pt(L)2(PPh3)2] complex (L: 5-heptyl-1,3,4-oxadiazole-2-(3H)-thione) was associated with a microemulsion (ME/PtII complex). The microemulsified system underwent physicochemical characterization, including pH, conductivity, rheology, zeta potential, and dynamic light scattering (DLS) measurements. The microemulsion system remained stable at a pH near 6.0, indicating biocompatibility, while the conductivity was between 7 and 8 μS cm-1, with a hysteresis area of -0.06 Pa s-1 for the ME/PtII complex. The DLS technique confirmed the presence of a microemulsion with particle sizes ranging from 10 to 200 nm. The polydispersity index for the ME/PtII complex system was close to 0.3, indicating a monodisperse system, with a zeta potential of -19.2 ± 4.49 mV. These results showed that the system containing the PtII complex and the microemulsion is thermodynamically stable. Subsequently, cell viability studies demonstrated that the ME/PtII complex system is not toxic to peripheral blood mononuclear cells (PBMCs). In the phagocytosis activity assay, the complex associated with the microemulsion showed an increase in the phagocytosis index, suggesting that the microemulsion (ME/PtII complex) has potential for new biological assays, such as antitumor and antibacterial.

Resumo em Inglês:

Human milk is the gold standard for newborn nutrition. When direct breastfeeding is not possible, donated human milk is recommended for premature or low-birth-weight infants. However, human milk banks face structural and logistical limitations, as they employ pasteurization as the standard treatment, which involves the use of temperature, and subsequently depend on a cold chain for storage and distribution. Freeze-drying appears to be a promising alternative, although still little used. It involves sublimation and water removal, extending shelf life and facilitating distribution. This study aimed to evaluate the fatty acid composition and quality of freeze-dried human milk during 90 days of storage at different temperatures (25 and 5 ºC), comparing it with raw and pasteurized human milk. The results, based on hierarchical cluster analysis of fatty acid composition, indicated that freeze-drying did not immediately alter the fatty acid profile and remained stable for up to 60 days, associated with prolonged refrigeration. Furthermore, freeze-dried human milk showed greater similarity to raw human milk. Variations in nutritional quality over time reinforce the predictions of freeze-drying, and further studies on other bioactive compounds are recommended to consolidate the technique in human milk banks.

Resumo em Inglês:

Bioactive peptides play essential roles in living organisms, acting as antioxidants, hormones, and regulators of physiological processes. The hydrolysis of chicken blood meal represents a promising strategy to enhance its nutritional and functional value by generating bioactive compounds with benefits to animal health. In this study, alkaline hydrolysate (AlkH) (NaOH ca. 1.04-2.08 M; ca. 98 °C) and enzymatic (Alcalase) protein hydrolysate (EPH) (pH 8.5; 60 °C) were optimized to maximize the release of water-soluble proteins, peptides, and amino acids while achieving a high degree of hydrolysis. After optimizing each route separately, we performed sequential combined hydrolysis (AlkH→EPH and EPH→AlkH) to test additivity/synergy. The organic nitrogen content was determined by the Kjeldahl method, and degree of hydrolysis (DH) was quantified using the o-phthalaldehyde (OPA). Peptides and amino acids were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and their potential bioactivities were evaluated through the BIOPEP database (BIOPEP). AlkH produced a broader spectrum of bioactive dipeptides, with optimal conditions of 10% NaOH and 15% substrate for maximum DH, and 5% NaOH with 30% substrate for the highest nitrogen recovery. Identified peptides included angiotensin-converting enzyme (ACE) and dipeptidyl peptidase (DPP-IV) inhibitors.

Resumo em Inglês:

The development of sustainable heterogeneous catalysts remains a significant challenge in green chemistry, particularly for reactions that are traditionally carried out under homogeneous conditions. In this context, we hypothesized that hybrid hydrogels formed by alginate (Alg) and iota-carrageenan (ι-CAR) could provide a complementary set of carboxylate and sulfate functional groups capable of efficiently immobilizing Cu2+ ions and generating an active, reusable catalytic platform. To test this concept, Alg/ι-CAR microspheres were prepared by Ca2+ ionotropic gelation followed by Cu2+ ion exchange, and their structural, morphological, and thermal properties were thoroughly characterized. The Fourier transform infrared (FTIR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), scanning electron microscopy with an energy-dispersive X-ray (SEM/EDX), and porosity analyses confirmed the successful incorporation of Cu2+ and revealed increased surface roughness and porosity after ion exchange, supporting the initial hypothesis of enhanced metal coordination within the hybrid matrix. The resulting Alg/ι-CAR-Cu2+ microspheres showed high catalytic activity in the Paal-Knorr synthesis of pyrroles, reaching 78% yield under mild conditions, and remained effective for up to three reuse cycles before gradual deactivation caused by partial Cu2+ leaching and surface densification. These findings demonstrate that the synergistic interactions between Alg and ι-CAR create a robust and efficient support for Cu2+ immobilization, highlighting the potential of biopolymer-based hybrid materials as sustainable heterogeneous catalysts for organic synthesis.

Resumo em Inglês:

Ovarian cancer is a major contributor to disease burden and fatalities globally, with earlystage cases posing substantial treatment hurdles due to restricted therapeutic modalities. Traditional Chinese Medicine (TCM) has gained attention for its diverse repertoire of natural compounds exhibiting possible antitumor effects. This research explores the therapeutic potential of oxypeucedanin hydrate (docking score of -9.75 kcal mol-1). Computational approaches were employed to assess the interaction strength between oxypeucedanin hydrate and the critical protein phosphoserine aminotransferase 1 (PSAT1) involved in ovarian cancer progression. Molecular dynamics (MD) simulations revealed the stability and conformational behavior of the compoundtarget complexes, mainly focusing on Trp107. Pharmacokinetic evaluation showed high intestinal permeability (QPPCaco = 468.389) and good oral absorption (83.94%). WaterMap analysis further supported its binding stability with a binding free energy (dG) of -15.41 kcal mol-1 and a favorable entropy contribution (-30.08 kcal mol-1). A 100 ns MD simulation confirmed the conformational stability of the OPH-PSAT1 complex, with a mean protein backbone root mean square deviation (RMSD) of 1.70 Å and ligand RMSD of 3.09 Å. MM/GBSA (Molecular Mechanics/Generalized Born Surface Area) analysis yielded an average binding free energy (dG_bind) of -63.88 kcal mol-1, outperforming reference ligand pyridoxamine phosphate (PMP) (-48.08 kcal mol-1). These findings position oxypeucedanin hydrate as a novel therapeutic candidate capable of suppressing tumor growth and triggering programmed cell death in ovarian malignancies.

Resumo em Inglês:

5,7-Dihydroxy-3-(4-hydroxybenzyl)-6-methylchroman-4-one, a biologically relevant chroman-4-one derivative previously identified from natural sources, was synthesized through a concise and efficient multi-step route starting from phloroglucinol. The synthetic sequence involves Friedel-Crafts acylation, Knoevenagel condensation, intramolecular Michael addition, and acid-catalyzed cyclization, providing practical access to this scaffold in good overall yield. The structure of the synthesized compound was unambiguously confirmed by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), Raman spectroscopy, and high-resolution mass spectrometry (HRMS). The compound exhibited notable antioxidant activity, as evidenced by its effective free radical scavenging performance in standard assays. In vitro cytotoxicity evaluation against a panel of human cancer cell lines revealed moderate to strong inhibitory effects, with halfmaximal inhibitory concentration (IC50) values of 16.7 ± 0.11 μM (HeLa), 24.6 ± 0.20 μM (HepG2), 39.2 ± 0.26 μM (A549), and 38.9 ± 0.19 μM (SGC-7901). These values represent a significant improvement compared to the parent chroman-4-one scaffold (IC50 > 96 μM for all tested cell lines) and are comparable to those of apigenin, a representative flavonoid reference compound. This study highlights an efficient synthetic approach and provides systematic in vitro antioxidant and cytotoxicity data for this chromanone derivative, supporting its relevance as a useful scaffold for further mechanistic studies and lead optimization.

Resumo em Inglês:

During the severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic, ivermectin (IVM), a broad-spectrum antiparasitic drug, was one of the medications prescribed to manage symptoms. However, its effectiveness against the virus has not been conclusively demonstrated. The increased consumption of IVM raised environmental and health concerns, including bioaccumulation and microbial resistance. To address these issues, electroanalytical methods have been explored for IVM detection, offering advantages such as low cost, portability, and high sensitivity. Super-P carbon black (SPCB) is a conductive nanomaterial used to modify glassy carbon electrodes, enhancing electrochemical performance. In this work, electrochemical sensors based on SPCB were developed using the drop-casting technique for IVM sensing. Through studies using cyclic voltammetry (CV), it was determined that the mass transport for the glassy carbon electrode modified with Super-P carbon black (SPCB/GCE) is governed by the adsorption of the species. After parameter optimization for differential pulse voltammetry technique, the sensor exhibited a linear working range of 10-100 µmol L-1, a limit of detection (LOD) of 1.3 µmol L-1, a limit of quantification (LOQ) of 4.2 µmol L-1, and a sensitivity of 0.101 µA µmol L-1. The developed method was applied to analysis of pharmaceutical tablets, tap water, and synthetic urine.

Resumo em Inglês:

Bacterial infections represent a significant public health problem. Escherichia coli (E. coli) is a bacterium capable of causing multiple types of infections; therefore, preventing bacterial adhesion and proliferation is crucial. In this report, it is presented the synthesis of polymeric films based on poly(2-vinyl-4,4’-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI), whose surface has been modified with amino acids. A bilayer consists of a first layer of PEI and a second layer of PVDMA (15 bilayers), and in the case of 15.5 bilayers, it refers to the fact that the last layer is with the PEI, and functionalized with amino acids (NH2). The present strategy is based on the preparation of covalently crosslinked thin films by the layer-by-layer method using PVDMA/PEI. The films were placed on a glass surface, and 15.5-layer films were prepared with the PEI polymer as the final layer, which contains amino groups on the surface. The final layer was functionalized with Fmoc-protected amino acids (glycine (Gly), alanine (Ala), leucine (Leu), and phenylalanine (Phe)). Finally, the Fmoc group was removed, yielding surfaces functionalized with amino acids and the free amino group (NH2). The films were characterized by Fourier transform infrared spectroscopy (FTIR), optical microscopy, and field emission scanning electron microscopy (FESEM). They were incubated with a green fluorescent protein (GFP) -modified E. coli strain for 2 h. The order of interaction of the bacteria with the modified surface is as follows: (F-Leu > F NH2 > F-Ala > F-Gly > F-Phe). The leucine-modified films effectively prevented E. coli adhesion.

Resumo em Inglês:

The aim of this study was to develop sustainable films based on collagen recovered from tanned leather waste with Hymenaea martiana stem extracts (HMEC) obtained by microextraction, with an emphasis on evaluating their physical and chemical properties. The phytochemical analysis of HMEC revealed a high content of phenolics (396.6 mg of gallic acid equivalents per gram of extract (mg EAG g-1) and flavonoids (296.2 mg of catechin equivalents per gram of extract (mg EC g-1)), with a predominance of flavonoids (74.7%). The liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-Q-TOF-MS) characterization evidenced a wide diversity of secondary metabolites, highlighting flavonoids such as fustin, isokaempferide, liquiritigenin, myricitrin, quercitrin, and quercetin derivatives, in addition to compounds such as quinic acid and glycosides. Furthermore, hydrolyzed collagen obtained from leather industry waste was combined with polyvinyl alcohol (PVA), glycerol, and different concentrations of HMEC to produce the films. The films exhibited high tensile strength (3833-4570 mPa), a significant increase in elongation at break (187.5-311.1%), and a swelling rate of up to 624.2% in samples with 3% HMEC, retaining 70% moisture after 18 h. The results highlight the great potential of these films for wound treatment and reinforce the sustainable reuse of leather industry waste.

Resumo em Inglês:

Recent years have highlighted the potential of flavonoids to enhance the efficacy and/or sensitivity of chemotherapeutics. The combination of histone deacetylase (HDAC) inhibitors with natural compounds has shown positive results. Thus, this study evaluates the association of pterocarpan and vorinostat, a potential epigenetic strategy against cancer cells, using in silico and in vitro approaches. The methodology involved using computational tools to map molecular targets and construct protein-protein interaction networks, followed by in vitro assays to evaluate cytotoxicity in cancer cell lines. The antiproliferative effects of the combination ((+)-2,3,9-trimethoxypterocarpan ((+)-PTC) + vorinostat) were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The combination index (CI) was calculated to determine synergistic effects between the compounds. Molecular target prediction followed by evaluation of up-or downregulated expression in PC-3 (prostate carcinoma), DU-145 (prostate carcinoma), KG-1 (acute myeloid leukemia), and MOLM-13 (acute myeloid leukemia) cell lines identified 36 targets, including interleukin 1 beta (IL1B), tumor necrosis factor (TNF), amyloid beta precursor protein (APP), MYC proto-oncogene, bHLH transcription factor (MYC) and Heat Shock Protein 90 (HSP90). Additionally, all vorinostat targets (HDACs 1-10) were evaluated. Docking experiments indicated stable complexes between (+)-PTC and HDAC1 (PDB: 4BKX), HDAC2 (PDB: 4LXZ), HDAC6 (PDB: 5B8D), and HDAC8 (PDB: 1T64). Minimum inhibitory concentrations varied among cell lines, with in vitro associations showing inhibitory concentrations ranging from 1.5 to 2.9 µM. The combination of (+)-PTC and vorinostat shows greater inhibition of cell proliferation than either compound alone.

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This article presents the design, synthesis, and biological evaluation of two series of piperine-based derivatives: benzyl piperate esters (12a-12d) and thiazole-acetamide hybrids (17a-17d). Scalable, low-cost synthetic routes afforded the target compounds in moderate to good yields (31-70%). Structural characterization was achieved by infrared spectroscopy (IR), one-dimensional nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). In silico absorption, distribution, metabolism, excretion, and pharmacokinetics (ADME) analysis indicated that the compounds are largely consistent with Lipinski’s and Veber’s criteria. Antibacterial activity was evaluated against clinically relevant Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. When analyzed on a molar basis, the compounds exhibited moderate intrinsic antibacterial activity, with minimum inhibitory concentrations typically in the hundreds to low thousands of micromolar range. In particular, para bromo derivatives and the meta-nitro thiazole displayed the lowest against S. aureus and selected E. coli strains. Mechanistic studies performed in multidrug-resistant S. aureus strains overexpressing NorA (nonoperating room anesthesia) or MsrA (methionine sulfoxide reductase A) efflux pumps demonstrated that the bromoand nitro-thiazole derivatives significantly reduced the minimum inhibitory concentration (MIC) of norfloxacin in NorA-expressing strains and in MsrA-expressing strains, consistent with the possibility of inhibiting the efflux pump.

Resumo em Inglês:

Water contamination from pesticides in industrial and agricultural effluents has significant environmental impacts, necessitating the development of effective treatment technologies. This article discusses the use of a combined electrochemical, photochemical, and sonochemical approach to degrade pesticides like ametryn, diuron, and hexazinone. A bench-scale electrochemical flow reactor with a Ti/Ru0.3Ti0.7O2 anode, Ti counter-electrode, and NaCl as the electrolyte was utilized. Process optimization involved varying electric current and NaCl concentration, with free chlorine species (FCS) production as the response variable. Optimal conditions were achieved at 0.88 mol L-1 [NaCl] and 0.78 A current. This photoassisted sonoelectrochemical process effectively degraded the pesticides, achieving total organic carbon (TOC) removal rates of 91, 94, and 77% for ametryn, diuron, and hexazinone, respectively. High-performance liquid chromatography (HPLC) analysis showed near-total removal for ametryn and diuron and 80.7% for hexazinone. Kinetic studies indicated that the degradation followed a pseudo-first-order model, with rate constants increasing approximately 1.8-2.5 times under the combined process compared to the electrochemical method. Additionally, this triple-combined approach enhanced current efficiency, reduced energy use, and improved overall system energy efficiency, proving to be an effective and promising treatment method.

Resumo em Inglês:

Glycerol is a co-product of biodiesel production and an important raw material for the synthesis of economically and ecologically valuable compounds. The etherification of glycerol with benzyl alcohol is a promising chemical route that leads to the formation of highly volatile monoand diethers with low viscosity and polarity. These compounds can be used as fuel additives to improve physicochemical properties, representing an alternative to increasing the biodiesel content in commercial diesel. Therefore, accurate and reliable protocols are required for the identification and quantification of the reaction products. In this study, a high-performance liquid chromatography method with ultraviolet-visible detection (HPLC-UV-Vis) was developed and validated to identify and quantify two ethers produced by glycerol benzylation. Method validation was carried out in accordance with Brazilian legislation and allowed efficient separation of the target compounds, here referred to as ether 1 and ether 2, showing satisfactory linearity in the concentration range of 150 to 400 µg mL-1, coefficients of determination of 0.9963 and 0.9990, and average recoveries of 105 and 74%, respectively. The method demonstrated accuracy, precision, and simplicity, proving suitable for monitoring the formation of glycerol ethers.

Resumo em Inglês:

This investigation aimed to identify the physicochemical traits of Paliurus spina christi Mill. seed oils gathered over the course of two years from various areas around Turkey, and to assess their applicability in vegetable oil technology. The physicochemical properties of the obtained P. spina christi oils were determined as follows: oil yield (12.45-15.76%), specific gravity (0.902-0.905 g cm-3), refractive index (1.4630-1.4705 nD), color (L* 37.39-44.87, a* -5.20-9.62, b* 45.49-57.09), viscosity (577.38-712.19 mPa), free fatty acidity (1.08-1.92%), peroxide value (0.63-0.78 O2 kg-1), iodine value (109.65-115.24), saponification (160.31-182.75 mg KOH g-1) and unsaponifiable matter (2.41-3.92) numbers. The oils exhibited moderate oil yields and were characterized by low peroxide and free fatty acid values, indicative of favorable oxidative stability. Analysis of the fatty acid profile revealed a dominance of palmitic acid (7.402-8.354%), oleic acid (37.818-45.959%), and linoleic acid (38.671-45.645%). This composition suggests a nutritionally advantageous profile, comparable to those of commonly consumed edible oils. Moreover, the existence of distinctive functional groups associated with triglyceride structures was verified by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) results elucidated thermal behavior typical of unsaturated vegetable oils. Consistent with these findings, P. spina christi seeds show potential as a novel raw material source for vegetable oil technology, based on their physicochemical properties. It is recommended that future studies investigate their refining characteristics.

Resumo em Inglês:

This study investigates the fuel properties of ethanol-butanol-gasoline emulsions prepared with varying ethanol concentrations (80, 90, and 96%) to develop stable and efficient alternative fuels. Key parameters evaluated include the research octane number (RON), Reid vapor pressure (RVP), fuel density, specific gravity (SG), distillation characteristics, and copper strip corrosion resistance, with an emphasis on stability and performance at temperatures between 15 and 30 °C. The results indicate that these fuel blends exhibit high octane ratings, with RON values ranging from 91.8 to 94.1, demonstrating strong anti-knock characteristics suitable for high-performance engines. The RVP increases from 41 to 50 kPa as ethanol content rises, supporting stability under diverse environmental conditions. Fuel density decreases from 0.798 to 0.759 g cm-3, while SG ranges from 0.770 to 0.715, reflecting the influence of ethanol content on fuel mass and volume. Copper strip corrosion tests conducted in accordance with American Society for Testing and Materials, ASTM D130 standards confirmed that all blends are non-corrosive, achieving a “Class 1” corrosion rating and ensuring compatibility with engines containing copper or other metallic components. Distillation tests revealed initial boiling points (IBP) between 41 and 45 °C and final boiling points (FBP) from 122 to 177 °C. Overall, these findings suggest that ethanol butanol gasoline emulsions offer notable benefits for enhancing engine performance, reducing emissions, and improving fuel stability.

Resumo em Inglês:

This study presents the design and synthesis of a series of quinazoline-dihydropyrimidinone hybrid compounds with potential antichagasic and antileishmanial activities, addressed to fight against neglected tropical diseases (NTDs). All compounds were evaluated against the epimastigote and trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania infantum, Leishmania braziliensis, Leishmania amazonensis, and Leishmania major. Among them, hybrids 7a and 7c showed significant activity against all parasites, surpassing the potency of the reference drugs miltefosine and benznidazole. Molecular docking simulation indicated strong interactions of hybrids 7a and 7c with key parasitic enzymes - such as cruzain from T. cruzi and sterol 14-alpha demethylase from L. infantum; dihydroorotate dehydrogenase from L. braziliensis; nucleoside diphosphate kinase (NDK) from L. amazonensis; and N-myristoyltransferase from L. major - which may underlie their observed in vitro efficacy.

Resumo em Inglês:

Global challenges such as health crises, rising sea levels, deforestation and biodiversity loss are linked to climate change, which is primarily caused by carbon dioxide (CO2) emissions. To address these issues, research into CO2 capture and reuse has gained prominence. Abundant, non-toxic to humans and inexpensive, CO2 is a promising raw material for energy and material production. However, converting CO2 into value-added products requires innovative approaches, such as the development of synthetic materials and catalytic processes. This study focuses on the use of silica extracted from rice husk ash, an agricultural residue comprising 20% of raw rice mass, as a support for metals such as cobalt (Co) and iron (Fe). The supported materials were evaluated for CO2 sorption and their catalytic performance in the direct synthesis of dimethyl carbonate (DMC) from methanol and CO2. Comprehensive characterization techniques, including field emission scanning electron microscopy (FE-SEM), surface area analysis (Brunauer Emmett Teller (BET) method), Fourier transform infrared spectroscopy with universal attenuated total reflectance (FTIR UATR), solid-state nuclear magnetic resonance (NMR-MAS), temperature-programmed oxidation-reduction (TPO), and temperature-programmed desorption (TPD), were employed. Catalytic performance was assessed using a Shimadzu GC 2014 gas chromatograph. The best CO2 sorption capacity was achieved with the sample Si-Co 10% (100 mg CO2 g-1) at 30 bar and 25 °C. The best conversion to DMC was for the sample Si-Fe 10% (22.91%), at 80 °C and 40 bar of CO2. This study demonstrates the potential of repurposing agricultural waste to extract silica and utilize it as a metal catalyst support, offering a promising solution for both CO2 capture and conversion.

Resumo em Inglês:

Compounds that inhibit the dopamine transporter (DAT) protein hold significant therapeutic potential for the treatment of various neurological disorders, including Parkinson’s disease and substance use disorders. In this context, an extensive quantitative structure-activity relationship (QSAR) study was conducted using 36 methylamine derivatives. Three modeling approaches were applied: a 2D-QSAR model based on classical descriptors, a 3D-QSAR model using molecular interaction field (MIF) descriptors, and a hybrid model combining the most relevant 2D and 3D descriptors. All models underwent the same statistical validation procedures. Although each model demonstrated high quality, the hybrid approach proved slightly superior. Furthermore, both the 2D-QSAR and MIF descriptors were found to correlate with the mechanism of DAT inhibition. These findings highlight that integrating complementary molecular information encoded in descriptors of different physicochemical origins can improve the predictive accuracy and robustness of QSAR models. The final model has the potential to serve as a tool to guide the synthesis and virtual screening of novel DAT inhibitors. It shows promising statistical performance and may assist preliminary virtual screening efforts.

Resumo em Inglês:

Long-term studies are essential to understand ecological and climatic processes in lotic ecosystems. This study analyzed the effects of changes in river discharge on hydrochemical parameters in the Lower Paraíba do Sul River (PSR) sub-basin over 11 years (2009-2019), in periods before and after a severe drought. The annual ions and particulate flow rates discharge and their relationship with the El Niño Southern Oscillation (ENSO) index were also estimated. Results revealed distinct response of hydrochemical parameters to discharge between the period before and after the severe drought. The occurrence of ENSO phenomena showed an influence on the hydrochemical dynamics at the end of the PSR basin, through changes in the local seasonality and, consequently, in the internal processes of the river channel, intensified by human activities on the soils of the basin. Our results reinforced that the increased frequency and intensity of climatic phenomena will in part affect hydrochemistry and transport patterns along the PSR. However, these effects on hydrochemical parameters prove to be contrasting. This highlights the need for further spatial and temporal scale studies on regulatory factors on hydrochemistry and its impact on water availability in the PSR basin in a scenario of anthropogenic and climate change.

Resumo em Inglês:

The aim was to verify the authenticity of commercial buffalo ricotta cheese samples by means of composition, chemical characteristics, electrophoresis and mid-infrared (MIR) spectroscopy combined with chemometric techniques. Eleven formulations with different proportions of cow whey (CW) and buffalo whey (BW), including samples with 100% CW and 100% BW, were produced and stored for 0, 15, and 30 days. A total of 14 commercial buffalo ricotta cheese samples was collected for authenticity verification. The analyses included composition (fat, protein, moisture, and ash), chemical characteristics (pH and titratable acidity), MIR spectroscopy, and electrophoresis. MIR data were subjected to principal component analysis (PCA) and analysis of covariance (ANCOVA). The composition and electrophoresis data did not identify fraud in commercial samples or distinguish between pure and adulterated samples. PCA discriminated samples primarily based on storage time. ANCOVA confirmed the relevance of time in most MIR bands, but the isolated concentration of CW was not significant, indicating the need for additional techniques to detect adulteration.

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HKUST-1 is a metal-organic framework (MOF) with the formula [Cu3(BTC)2(H2O)3]n (BTC: benzene-1,3,5-tricarboxylate), which exhibits relevant properties due to its high porosity. However, HKUST-1 is highly sensitive to water, collapsing in aqueous media or under high-humidity conditions. The modification of this MOF with metal nanostructures has seen significant growth in recent years, with gold nanoparticles (AuNPs) among the most widely used. This article reports the association between gold nanoparticles (AuNPs) and MOF HKUST-1 and investigates the influence of water from AuNPs on the degradation of HKUST-1, in addition to proposing a modification that maintains the stable structure, based on the transfer of gold nanoparticles to a non-aqueous medium (N,N-dimethylformamide) before the modification of HKUST-1. An analysis of the influence of the ethanol washing process on gold-modified HKUST-1 samples was also performed.

Resumo em Inglês:

The Fabaceae family is characterized by remarkable chemical diversity, especially alkaloids, which play a central role in taxonomic studies and drug development. Among its genera, Erythrina and Sophora stand out for the structural variety of their alkaloids and their significant pharmacological potential. This study applied self-organizing maps (SOMs) to chemotaxonomic analysis, using a database of 650 alkaloids derived from 129 species and 747 botanical occurrences. Therefore, SOMs were applied to investigate structural patterns in alkaloids from the genera Erythrina and Sophora based on molecular descriptors. A dataset composed of occurrence-based records and unique molecular structures was analyzed to evaluate the influence of structural redundancy on model performance. The SOMs showed high classification consistency, achieving overall accuracy above 90% in both approaches, with comparable precision, recall, and F1 values for the two genera. Descriptor distribution analyses suggested that Erythrina alkaloids are characterized by a higher degree of unsaturation and a greater content of sp2 carbons, whereas Sophora alkaloids tend to present a higher proportion of sp3 carbons, larger ring systems, and non-aromatic imines. The similarity between the results obtained from occurrence data and unique molecules demonstrates that SOM performance is preserved even after the removal of redundant structures. These results indicate that SOMs constitute a robust exploratory tool for the chemotaxonomic analysis of these alkaloids, although additional validation using other datasets and the integration of a larger amount of biological data are required to confirm the observed patterns.

Resumo em Inglês:

Cembratrien-diol is an important precursor of cigarette aroma, but the preparation of high-purity cembratrien-diol is still difficult. In this experiment, deep eutectic solvents were used to extract cembratrien-diol from tobacco inflorescences, and then cembratrien-diol was recovered from the deep eutectic solvent extracts by liquid-liquid extraction. The best deep eutectic solvent was synthesized to extract cembratrien-diol from tobacco inflorescence by mixing choline chloride as hydrogen bond acceptor with 1,2-propanediol as hydrogen bond donor in a molar ratio of 1:4 and with water content of 20% (v:v). The optimal liquid-liquid extraction process conditions were solid-liquid ratio of 1:30, extraction time of 24 h, petroleum ether as solvent for liquid-liquid extraction, volume of petroleum ether of 100 mL, and liquid-liquid extraction time of 6 h. The highest extraction yield of cembratrien-diol was 4.41 mg g-1, and the highest purity of cembratrien-diol was 82.3%. α-Cembratrien-diol and β-cembratrien-diol were separated and purified by semi-preparative high-performance liquid chromatography, and the purity of both cembratrien-diol exceeded 95%. In this study, deep eutectic solvents were combined with liquid-liquid extraction technique to extract and separate cembratrien-diol. This method can effectively separate and purify high-purity cembratrien-diol from tobacco inflorescences and also could be expected to be applied to the high-purity preparation of other compounds.

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This study applied an integrated in silico workflow to design and evaluate chromone-based derivatives (1-20) as selective cyclooxygenase-2 (COX-2) inhibitors with prospective anti-inflammatory activity. Computational methods included density functional theory calculations at the B3LYP/6-31G(d,p) level, molecular docking, ADMET (absorption, distribution, metabolism, excretion, and toxicity) prediction, and molecular dynamics simulations. Among all screened compounds, ligand 3 demonstrated superior binding affinity toward COX-2 (-10.9 kcal mol-1) relative to celecoxib (-9.4 kcal mol-1). Docking revealed stable interactions with critical active site residues, including Gln (glutamine), Leu (leucine), His (histidine), and Val (valine). Density functional theory (DFT) results showed a relatively low HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital) energy gap of 3.820 eV, indicating enhanced chemical reactivity and potential biological activity. Molecular dynamics simulations of the ligand 3:COX-2 (cyclooxygenase-2) complex (PDB ID: 5F19) confirmed structural stability across temperatures from 300 to 320 K, with low root mean square deviation (RMSD) fluctuations of approximately 0.4 nm and consistent radius of gyration values, and optimal stability observed at 31 K. ADMET analysis predicted good intestinal absorption and moderate lipophilicity (LogP 1.86); however, high molecular weight (623.67 g mol-1) and elevated topological polar surface area (160.03 Å2) may compromise oral bioavailability. Overall, ligand 3 appears to be a promising COX-2 selective inhibitor. However, reliance on predictions requires experimental validation.

Resumo em Inglês:

Cadmium contamination in aquatic environments poses significant environmental and health risks, reinforcing the need for sensitive and selective analytical approaches. Traditional sample preparation techniques often fall short in selectivity and sensitivity, motivating the development of alternative strategies. This study introduces a novel hybrid method that combines cloud point extraction (CPE) with magnetic solid-phase extraction (MSPE) for the efficient extraction of cadmium ions from aqueous samples. Moringa oleifera shells, modified with a ferromagnetic fluid, were employed as an eco-friendly and low-cost magnetic adsorbent and fully characterized. Key parameters such as extraction pH and adsorbent mass were optimized, establishing pH 6 and 20.0 mg. A 24 factorial design identified optimal extraction conditions with 1% Triton X-100, 1.0 mol L-1 HNO3, 5 min sonication, and 6 min heating. Selectivity was assessed via a fractional factorial design involving seven metal ions, revealing no interference from CoII, FeIII, MnII, and NiII. The method demonstrated good analytical performance, with a sensitivity of 1.8 ×10-3, linear range of 0.25 2000.0 µg L-1, limit of detection (LOD) of 3.45 µg L-1, limit of quantification (LOQ) of 11.5 µg L-1, and precision values of 7.71% (overall), 5.12% (repeatability), and 2.56% (reproducibility).

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Polymeric [CuX1(DCQ)]n (DCQ = 4,7-dichloroquinoline, X1 = Cl, Br, I) and dimeric [CuX2(DCQ)(PPh3)]2 (PPh3 = triphenylphosphine, X2 = Cl, Br) complexes were synthesized and characterized by powder X-ray diffraction (PXRD), single crystal X-ray diffraction (SCXRD), spectroscopy, and analytical methods. In the solid state, the photophysical response varied with the halide, with emission colors spanning red to yellow and showing measurable halide-dependent changes in emission energy (EPL), Stokes shift, photoluminescence quantum yield (ΦPL), and average lifetime (τ). Time-resolved measurements revealed millisecond lifetimes, suggesting the participation of long-lived excited states with charge transfer (CT) character. Density functional theory (DFT) calculations were consistent with low-energy excited states with mixed metal-to-ligand (MLCT), metal/halide-to-ligand charge-transfer ((MX)LCT) and ligand-ligand charge transfer (LLCT) characters and singlet-triplet energy state that could facilitate the intersystem crossing (ISC) within qualitative framework. Emissions of the five copper(I) complexes were observed in the solid-state, whereas no measurable luminescence was observed in common solvents. Overall, the photoluminescence reflected the combined influence of the CuI coordination environment, halide identity, and solid-state structural constraints.

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Raman spectroscopy is a powerful tool for assessing the thermal maturity of kerogen; however, its application to carbonate-rich source rocks is hampered by methodological challenges, particularly spectral interference from fluorescent mineral matrices and sample heterogeneity. This study systematically evaluates three preparation protocols: fresh (raw), macerated (ground), and decarbonated, on samples from the Formação Coqueiros (Campos Basin-RJ, Brazil) to identify the most reliable workflow, using Rock-Eval pyrolysis as a geochemical benchmark. Direct analysis of fresh samples proved unreliable, yielding inconsistent data in which the combined effects of heterogeneity and mineral fluorescence masked the true kerogen signal. While mechanical maceration successfully addressed physical heterogeneity, allowing for a basic qualitative distinction between maturity levels, it was insufficient, as the fundamental problem of spectral interference remained unresolved. The decarbonated protocol, however, yielded the optimal result. This two-step procedure, involving mechanical grinding followed by targeted chemical removal of carbonates, successfully mitigated both issues, producing stable, precise, and geologically coherent maturity data that correlates with the Rock-Eval temperature of maximum hydrocarbon generation (Tmax) benchmark. This work validates the targeted procedure as a robust, accessible workflow that avoids aggressive chemical treatments that risk altering the kerogen structure, offering a more efficient and potentially more accurate path for analysis in these common lithologies.

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In Brazil, organochlorines pesticides (OCP) were used to combat vectors until the 2000s, and their residues are still present in environmental and biological matrices. Therefore, it is essential to assess the historical exposure of vector control workers (VCW). This article has two main objectives, to describe the validation of analytical methodology, and to assess simultaneous quantification of 26 analytes, between OCP and related transformation products, in blood plasma for VCW exposure levels. The occupational exposure of 127 VCW from Rio de Janeiro State, Brazil, to 26 analytes in blood plasma samples was evaluated using solid-phase extraction (SPE) for sample preparation and gas chromatography coupled to mass spectrometry (GC-MS/MS). The method performance met acceptance criteria according to Brazilian guideline showing linearity with correlation coefficients (R) between 0.936 and 0.994 in 0.2 to 15 ng mL-1 range; recovery between 93 to 105%; limit of detection (LOD) of 0.015 to 0.468 ng mL-1, and limit of quantification (LOQ) of 0.045 to 1.419 ng mL-1; precision with coefficients of variation < 20%. VCW samples presented 52% dichlorodiphenyltrichloro-ethane (DDT) isomers and related transformation products (0.15 to 8.22 ng mL-1), and 12% contained beta-hexachlorocyclohexane (HCH) residues (0.09 to 0.28 ng mL-1). It was possible to demonstrate high prevalence of VCW with residues, even after the cessation of exposure years ago.

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Biodegradable coatings can improve fruit storage, but physical and chemical interactions might impair performance. This work coated strawberries with a blend based on cassava starch (native, oxidized, or acetylated), gelatin, sorbitol, and two antimicrobial agents (calcium propionate and potassium permanganate) to evaluate potential downsides of exposure to an acidic environment. The coatings varied in thickness (0.124-0.160 nm), opacity (1.37-4.61), solubility (29-55%), and color. Mass loss analysis indicated limited efficiency (the 10% threshold was reached within 48 h) in strawberries due to potential hydrolysis reaction. Soluble solids, titratable acidity, harvest index, and vitamin C concentration confirmed that hydrolysis under acidic conditions strongly impaired acetylated starch coating performance, performing worse than the control group. Further studies are needed to evaluate coating behavior in non-acidic fruits and under different pH conditions.

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Macrolides, a class of broad-spectrum antibiotics, are gaining attention for their potential in treating parasitic infections due to their favorable safety profiles, pharmacokinetics, and tissue penetration. This study explores the possibility of repurposing macrolides for the treatment of schistosomiasis, a neglected tropical disease caused by the trematode Schistosoma mansoni. Using computational approaches and molecular docking, including quantitative structure-activity relationship (QSAR) models, we evaluated the predicted binding affinities and inhibition probabilities of macrolides against S. mansoni thioredoxin glutathione reductase (SmTGR), a key enzyme in the parasite redox balance. The virtual screening identified eight promising macrolides, with Sorangicin A emerging as a promising hit compound due to its strong predicted interactions with SmTGR. The results suggest that Sorangicin A and other macrolides may exhibit potential antischistosomal activity, highlighting their viability as repurposed therapeutics. This study underscores the value of leveraging established drug classes for new applications, particularly in addressing neglected diseases. Combining QSAR and molecular docking, we demonstrate a costand time-efficient strategy for identifying novel treatments. It is offered a pathway to combat schistosomiasis and other parasitic infections, which must be validated experimentally.

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By comparing the carbon dioxide (CO2) absorption performance of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm]BF4), 1-propynyl-3-butylimidazolium tetrafluoroborate ([APMIm]BF4), and 1-butyl-3-methylimidazole lysine ([BMIm]Lys), [BMIm]Lys exhibits a markedly higher CO2 uptake over the range of 1-10 bar. After CO2 absorption, both [BMIm]Lys and [APMIm]BF4 display a characteristic carbamate band at 1692 cm-1 in their Fourier transform infrared spectroscopy (FTIR), indicating the involvement of chemisorption. Subsequently, zirconium 1,4-dicarboxybenzene metal-organic framework (UiO-66(Zr)) and zirconium aminobenzenedicarboxylate metal-organic framework (NH2-UiO-66(Zr)) were used as supports to immobilize [BMIm]Lys via impregnation, producing [BMIm]Lys@UiO-66(Zr) and [BMIm]Lys@NH2-UiO-66(Zr) for CO2 capture/separation. X-ray diffraction (XRD) confirms that the crystalline framework is preserved after immobilization, while Brunauer-Emmett-Teller (BET) analysis suggests partial occupation of the pore structure. NH2 functionalization increases the CO2 capacity by factors of 1.73 and 1.51 at 0.2 and 0.8 bar, respectively, and [BMIm]Lys immobilization further strengthens the low-pressure affinity for CO2. Notably, [BMIm]Lys@NH2-UiO-66(Zr) achieves a CO2 uptake of 5.18 mmol g-1 at 0.8 bar and 30 °C, accompanied by an exothermic adsorption feature. Moreover, the CO2/N2 selectivity of [BMIm]Lys@NH2-UiO-66(Zr) reaches 468.2 at 0.1 bar and 158.4 at 0.8 bar. After seven adsorption-desorption cycles, [BMIm]Lys@NH2-UiO-66(Zr) retains 94.98% of its initial CO2 capacity, demonstrating promising regenerability for practical applications.

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Strawberry fruit development is accompanied by pronounced changes in chemical composition, particularly in hormone levels and antioxidant metabolites. This study systematically characterized the temporal dynamics of abscisic acid (ABA), ascorbic acid (AsA), and phenolic compounds across nine developmental stages using chromatographic and mass spectrometric analyses. Early stages were marked by high concentrations of flavan-3-ols, including catechins, and phenolic acids. Intermediate stages exhibited a strong increase in AsA content and the initial accumulation of pigment-related phenolics. During ripening, sharp increases in ABA and its conjugated form, ABA-glucosyl ester, coincided with the accumulation of anthocyanins-predominantly pelargonidin derivatives-and enhanced phenolic glycosylation. Correlation analyses revealed positive associations between ABA and glycosylated phenolics, as well as a negative correlation between ABA and AsA. These results indicate a coordinated metabolic reprogramming during strawberry development, in which ABA accumulation is closely linked to phenolic modification and pigment formation, providing a chemical framework for improving fruit quality and postharvest performance.

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Terahertz time-domain spectroscopy (THz-TDS) was used to measure the absorption spectra of salicylic acid (SA) and acetylsalicylic acid (ASA) from 0.4 to 2.0 THz. Theoretical calculations were performed using the B3LYP-D3 and M06-2X methods within the density functional theory (DFT) framework. Comparative analysis showed that B3LYP-D3 results aligned more closely with experimental data. To understand the origins of absorption peaks, the potential energy distribution method (PED) assigned corresponding vibration modes, revealing that peaks of SA stem mainly from bond angle bending, while those from ASA arise from both bond angle bending and dihedral angle torsion. Qualitative and quantitative analyses of weak intermolecular interactions using interaction region indicator (IRI), energy decomposition analysis based on force field (EDA-FF), and electrostatic potential (ESP) methods indicated that electrostatic interactions primarily influence hydrogen bonds, while dispersion effects act on carbon and oxygen atoms, contributing significantly to total binding energy. This study links terahertz spectral differences to weak intermolecular interactions, enhancing understanding of molecular structures and guiding material applications.

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Madeira River (Rondônia State, Brazil) is known to be contaminated with mercury (Hg), which can be biomagnified and bioaccumulated through the food chain. The situation raises concern given there are riverside inhabitants that consume fish. Therefore, 18 fish species with a broad spectrum of eating habits were investigated. Mercury concentrations in fish muscle were evaluated according to the limits established by the Brazilian National Health Surveillance Agency (ANVISA) and the European Union (EU). ANVISA sets maximum limits of 1.0 µg g-1 for predator species and 0.5 µg g-1 for non-predator species (Brazil), whereas EU establishes a maximum limit of 0.5 µg g-1 (EU). Thirteen species have Hg levels above the maximum recommended (ANVISA limits). The Hg concentration ranged from 0.15 to 20.7 and 0.012 to 1.14 µg g-1 for predatory and non predatory fish, respectively. A flow batch chemical vapor generation-inductively coupled plasma mass spectrometric (CV-ICP-MS) method was used, with limit of detection (LOD) of 0.012 µg g-1, value below the maximum limit for mercury in fish established by ANVISA and the European Union. Accuracy was evaluated by analyzing certified refence material (CRM), with precision better than 5% (relative standard deviation, n = 5). The results demonstrate the current status of Hg in fish and highlight the seriousness of environmental contamination, as mercury concentrations in several species exceed expected levels. In addition, Hg levels in fish muscle are comparable to or higher than those reported in studies conducted in the same region since 2000.

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The codling moth, Cydia pomonella (L.), is a globally significant pest of apple orchards. Its developing resistance to conventional pesticides necessitates the exploration of alternative control agents, particularly for post-harvest protection. This study characterizes the chemical composition and evaluates the fumigant toxicity of an essential oil (EO) extracted from an ecotype of Artemisia herba-alba Asso. previously unstudied in the Aurès region (Algeria). The hydrodistillation yielded 0.36 ± 0.01% (v/m) of a pale-yellow oil. Gas chromatography-mass spectroscopy (GC-MS) revealed an uncommon ocimene/terpineol-rich chemotype, distinct from ordinary camphor or thujone-dominated profiles. The relative amounts (semi-quantitative) were dominated by alloocimene (31.13%), α-terpineol (23.67%), and 4 thujanol (17.12%). Bioassays against fifth-instar larvae demonstrated significant fumigant toxicity, with a 24 h LC50 (lethal concentration) value of 25.81 μg mL-1 air. This efficacy is comparable to that of other plant derived insecticides reported in the literature, confirming the oil potential as a viable botanical fumigant. The discovery of this uncommon chemotype not only expands the known chemical diversity of A. herba-alba but also positions its EO as a promising, eco friendly candidate for integration into post-harvest integrated pest management strategies against C. pomonella.

Resumo em Inglês:

Oral caries is a major global public health issue involving complex biofilm interactions and contributing to several systemic conditions. Metallic compounds have gained attention as antimicrobial agents due to their notable antibacterial activity. In this work, we investigated the anticariogenic potential of two copper(II) complexes containing Schiff base ligands, namely [CuCl(atc-Me)] (1, atc-Me = 2-acetylpyridine-N(4)-methyl-thiosemicarbazone) and [{Cu(μ atc Me)}2μ-SO4] (2). Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC50), and synergistic activity with chlorhexidine were evaluated. The in vivo toxicity of the complexes was further assessed using Caenorhabditis elegans. MBC values indicated a bactericidal effect for both complexes. Synergistic activity with chlorhexidine was observed against Streptococcus mutans and Enterococcus faecalis strains. Cytotoxic evaluation in human fibroblast cultures revealed that complexes 1 and 2 showed half maximal inhibitory concentration (IC50) values of 2.9 and 4.9 µg mL-1, respectively. Toxicity assays in C. elegans showed lethal concentration (LC50) values approximately three times higher than the MIC values for complexes 1 and 2: Molecular docking analyses revealed favorable binding energy values between the copper complexes and bacterial proteins. Overall, this investigation suggests an alternative approach for anticariogenic treatment, highlighting significant antibiofilm activity combined with low toxicity.

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Psilocybin is a molecule with significant potential for the treatment of mental disorders such as depression, anxiety, post-traumatic stress disorder, and substance abuse. In this study, it was explored the extraction of psilocybin from Psilocybe cubensis mushrooms using a factorial design approach, along with the physicochemical and phytochemical characterization of the extracted material, aiming to optimize the process. The results indicate that the optimal extraction conditions were achieved using an acidified ethanol solvent (without water addition) at pH 2 and at temperature of 25 °C. The maximum yield obtained was 50.03 mg of psilocybin g-1 of extract (ca. 1% psilocybin), which exceeds the values reported in the literature for similar studies, demonstrating the efficiency of the proposed method. Through liquid chromatography-mass spectrometry (LC-MS/MS) analysis, six compounds were annotated: the indole alkaloids psilocybin and psilocin, previously reported in the P. cubensis genus, and four additional compounds, sn-glycero-3-phosphocholine, norvaline, tetronomycin and N-(tetradecanoyl)-sphinganine, which have not previously been reported in the Psilocybe genus.

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Owing to the broad medicinal and agrochemical applications of cholinesterase inhibitors, the search for new molecules exhibiting this activity, particularly those with novel structural frameworks, is of great interest. Caffeine was selected as the base scaffold for the synthesis of new anticholinesterase compounds due to its neuroprotective effects and its favorable blood brain barrier permeability constant, which facilitates action in the central nervous system. In this study, six caffeine derivatives were synthesized (yields ranging from 51-95%), incorporating functional groups inspired by commercially available acetylcholinesterase (AChE) inhibitors. Among the compounds obtained, the brominated analog (CAF-Br (2)) stood out by exhibiting the highest inhibitory activity against AChE (55% inhibition at 50 μmol L-1). Computational studies conducted herein suggest that the formation mechanism of this derivative most likely proceeds via an electrophilic aromatic substitution (SEAr) pathway, rather than through a radical mechanism. In addition, molecular docking analyses, together with physicochemical parameter evaluations, indicate a possible association between smaller structural volumes and increased AChE inhibitory effects.

Resumo em Inglês:

Ni-Mo alloys, promising candidates as environmentally safer alternatives to Cr coatings, were electrodeposited on a copper substrate. A full 22 factorial design was conducted to evaluate the effects of electrolyte pH (ranging from 4 to 8) and cathode rotation (10 to 50 rpm) on composition, microstructure, texture, and corrosion resistance. Results indicate that only pH significantly affects molybdenum content in the alloy, ranging from 15.81 to 49.65 at%. The increase in Mo content changed the surface morphology from nodular to compact, smooth, and crackled layer. Additionally, Ni-Mo alloys with Mo contents above 40 at% exhibited an anomalous growth along the less energetically favorable (2 2 0) crystallographic plane. Electrochemical measurements were carried out in 0.1 M NaCl, revealing an abnormal result: the alloy containing 39.47 at% Mo exhibited the lowest corrosion current (1.351 µA cm-2) and the highest charge transfer resistance (5.53 kΩ cm2). Overall, corrosion behavior appears to be predominantly governed by Mo content, while surface morphology and crystallographic texture exert a secondary influence. Thus, the alloy containing 39.47 at% Mo with nanocrystalline microstructure, is a promising material for anticorrosion coatings and surfaces.

Resumo em Inglês:

In the present study, pine wood and sugarcane straw were chosen to represent the biomass classes of forest and agricultural residues. Lignocellulosic biomasses were submitted to slow and fast pyrolysis in an experimental-scale laboratory unit at temperatures ranging from 400 to 600 °C. The solid (biochar) and liquid (bio-oil) products were characterized, and physicochemical properties and chemical composition were analyzed. Experimental results revealed significant differences depending on the biomass type and the pyrolysis conditions. An increasing in heating rate and pyrolysis temperature led to higher liquid phase yields and enhanced higher heating values of the solid phase. Proximate analysis of biochar showed notable variations in moisture, ash, volatile matter and fixed carbon contents, while infrared spectroscopy indicated differences in functional groups. Bio-oil analyses showed similar water content and acid values across the investigated conditions, indicating limited sensitivity to process parameters, although significant differences were observed among biomass types. Elemental analyses covered metals, as alkaline and alkaline earth elements, as well as Cl, P and S. Results demonstrated that some elements remained in higher concentrations in biochar, being Al, Ca and, K the predominant inorganic constituents. In contrast, bio-oil presented lower concentration of elements, with Al and S as the major contaminants.

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The growing demand for renewable alternatives has driven the exploration of vegetable oils as promising raw materials for polymer production. In this study, three oils of relevance in Brazil, baru oil, macaw oil, and castor oil were characterized in terms of their iodine value, free fatty acid content, and thermal and spectroscopic properties. These oils were also structurally modified to obtain monomers suitable for 3D printing. Characterization was performed using thermoanalytical and spectroscopic techniques to evaluate thermal stability, degradation events, the presence of functional groups, fatty chain composition, and the conversion of each structural modification. The results revealed notable differences: baru oil presented significant levels of monounsaturated fatty chains, mainly oleate ester, which represents 48% of the total composition; the macaw oil showed the highest iodine value among the oils studied, while castor oil stood out for its high content of ricinoleate ester. Additionally, the results demonstrate that even low degrees of acrylation in epoxidized oils are sufficient to yield polymeric materials, underscoring the potential of these renewable resources for the development of sustainable polymers derived from natural feedstocks of Brazil.

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Benzothiazole and benzimidazole derivatives are widely recognized as important scaffolds in drug development and pharmaceutical applications. In this study, we report the microwave-assisted synthesis of a series of styrylbenzothiazoles and styrylbenzimidazoles in the presence of sodium bisulfite (NaHSO3), along with the evaluation of their cytotoxic activities against the MDA-MB-231 (human breast carcinoma) and 4T1 (mouse metastatic mammary adenocarcinoma) tumor cell lines, using MCF-10A cells to assess selectivity. With the exception of compound 2e, all thiazole derivatives exhibited cytotoxic activity to varying extents against the MDA-MB-231 cell line, whereas no activity was observed against the 4T1 cell line. Compound 2f, an amino-substituted derivative, displayed the highest cytotoxic activity (IC50 = 4.0 μM), being twice as potent as the reference drug cisplatin (IC50 = 9.6 μM) and 9-25 times more potent than the other derivatives in the series. Styrylbenzimidazole derivatives 3d, 3g, and 3k also showed promising activity against MDA-MB-231 cells, with IC50 values of 8.2, 6.6, and 5.9 μM, respectively. Notably, unlike the thiazole derivatives, styrylbenzimidazoles exhibited cytotoxic activity against the 4T1 cell line, with the methoxy-substituted derivative 3d showing the highest potency (IC50 = 8.4 μM). Competitive deoxyribonucleic acid (DNA)-binding studies involving compounds 2d, 2f, 3d, and 3f with ethidium bromide (EB) or 4’,6-diamidino-2-phenylindole (DAPI) suggested a preferential interaction with DNA via the minor groove, while interaction assays with bovine serum albumin (BSA) confirmed their protein-binding ability. These findings were further supported by molecular docking and density functional theory (DFT) calculations.

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In this study, a methodology was developed to determine Fe, Mn and Zn by flame atomic absorption spectrometry (FAAS) in soy milk samples. Samples were treated by dissolution with tetramethylammonium hydroxide (TMAH) using ultrasound energy. Doehlert design was applied in the multivariate optimization of the following variables: sonication time, TMAH volume and temperature during dissolution. The desirability function was used to find the optimum region. The methodology presented limits of quantification of 14.2, 4.7, and 0.73 mg kg-1, precision, expressed as repeatability (relative standard deviation (RSD), 2.0 mg L-1, n = 10), of 1.5, 1.3, and 0.95%, respectively, for Fe, Mn, and Zn. Accuracy was assessed by addition/recovery tests (recoveries in the range of 93 and 105%), comparison with another method adopted as a standard (acid digestion in a digester block), and analysis of a certified reference material (powdered skimmed milk, ERM-BD150). The method presented adequate accuracy for determining the elements studied in soy milk samples.

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Volatile organic compounds (VOCs), emitted by natural and anthropogenic sources, interact with solar radiation and participate in complex photochemical processes in the atmosphere. They influence air quality and climate on a local, regional, and global scale, either as greenhouse gases or through the formation of secondary aerosols. Understanding their emission sources, chemical transformations, and impacts remains a significant challenge for predicting climate change and developing environmental control and monitoring strategies. The results presented in this work correspond to the application of machine learning models, in conjunction with chemoinformatics tools, to predict the formation of organic compounds from molecules present in diesel fuel. Specific chemical oxidation reactions involving OH radicals, ozone, and atomic oxygen were studied using resources from the RDKit library in Python. The set of 261 reactant molecules in diesel were generated using a generative neural network. Multiclass classification models were also built to predict the toxicity (mutagenicity - Ames test) of these molecules using quantitative structureactivity relationship (QSAR), along with the ISSSTY database, providing good predictive results.

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The accurate determination of stamping time holds significant importance for forensic document examination and authentication. To address the critical challenge of determining the age of stamp impressions in document forensics, this study proposed a non-destructive predictive method based on hyperspectral imaging (HSI) technology and support vector machine (SVM) algorithm for estimating the stamping age. Hyperspectral data were collected from stamp impressions made with two oil-based inks at 27 time points, spanning a range of 0.42 to 205 days. A predictive model for impression age was constructed by integrating these data with SVM algorithm. This model was systematically compared against other machine learning (ML) approaches. The experimental results demonstrated that the SVM model achieved optimal performance on the test set, with a Nash-Sutcliffe efficiency coefficient (NSE) of 0.99 and a root mean square error (RMSE) of 7.69 days. This performance significantly surpassed that of the extreme learning machine (ELM) model (NSE = 0.78, RMSE = 24.64 days), the backpropagation neural (BP) network (NSE = 0.95, RMSE = 12.19 days), the partial least-squares (PLS) model (NSE = 0.84, RMSE = 20.68 days), and the long short-term memory (LSTM) model (NSE = 0.94, RMSE = 12.89 days). This study provided a novel technical reference for the accurate prediction of stamp impression age.

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The density, viscosity, electrical conductivity, and electrochemical window of aluminum chloride-1-ethyl-3-methylimidazole chloride (AlCl3-EMImCl) ionic liquid were systematically determined across a broad temperature range. The ionic liquid was functionalized with four inorganic additives (LiCl, LiBr, NaCl, NaBr) and three organic additives (ethylene carbonate (EC), tetrahydrofuran (THF), 1,2-dichloroethane (DCE)). The results demonstrate that inorganic additives increase the density of AlCl3-EMImCl, while organic additives result in a density reduction. Among all additives, DCE and THF show the most remarkable viscosity-reducing effects. Influence of additives on electrical conductivity follows the order: DCE > THF > LiCl, LiBr > NaCl, NaBr > blank > EC. Except for LiBr and NaBr, all other investigated additives do not narrow the electrochemical window of AlCl3-EMImCl. Soft-pack battery tests further validate that THF significantly enhances coulombic efficiency without obvious capacity decay. This work provides comprehensive experimental data and useful selection references for additives, supporting the potential application of AlCl3-EMImCl electrolytes in aluminum-ion batteries.

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Croton L. (Euphorbiaceae) comprises species found in tropical and subtropical regions and is known for its rich phytochemical diversity, particularly its terpenoids, which exhibit cytotoxic, antimicrobial, and antioxidant activities. Croton argyrophylloides is a species found in the Caatinga biome and occurs throughout all states of Northeastern Brazil. This study investigates the chemical diversity of compounds isolated from C. argyrophylloides from hexane (1-4) and dichloromethane/ methanol (5-13) extracts of the aerial parts. Structural characterization was performed using nuclear magnetic resonance (NMR) techniques (1H, 13C, and 2D), comparison with data from the literature, along with high-resolution electrospray ionization mass spectrometry (HR-MS), infrared (IR), and electronic circular dichroism (ECD) for the new compounds. Phytochemical investigation led to the structural elucidation of thirteen compounds (1-13), including two new diterpenes: a crotofolane-type skeleton, argyrotrienone A (3), and a rare isocrotofolane-type carbon skeleton, argyrotrienone B (4). These findings expand the structural diversity of diterpenes and highlight the phytochemical potential of Croton species as a valuable source of novel natural products.