Camu-camu (Myrciaria dubia K.), native to the Amazon region, offers significant therapeutic potential due to its high content of bioactive compounds. However, the characterisation of its seeds is still limited. The study aims to characterise the chemical composition in the seed and antioxidant potential in different extracts. The camu-camu seed flour was subjected to UHPLC-HRMS analysis and the antioxidant activity was evaluated by the DPPH, ABTS, FRAP, ORAC and FOLIN methods. The phenolic compounds coumaric acid, scopolin, 2,3-dihydroxybenzoate, 2′,4-dihydroxychalcone, dihydroxymandelic acid and isoquercetin were identified. In the antioxidant analysis, the hydroalcoholic extract showed superior capacity when compared to the aqueous extract in all methods. The compounds scopolin, 2′,4-dihydroxychalcone and dihydroxymandelic acid were identified for the first time in the camu-camu seed, and further studies are needed on the relationship between the activity of these compounds and how the structural position affects the antioxidant activity of the camu-camu.

The efficient detectionof nerve agents is paramountin civilianand war contexts. In this work, we investigated theoretically themechanisms of fluorescence quenching and charge transfer (CT) in tworecently synthesized small molecule fluorescent probes for detectingnerve agents, NMU-1 and 10-hydroxybenzo­[h]­quinoline(HBQ-AE), which are based on the pyridine group as the identifyingunit. These fluorescent molecules change their emission pattern uponbinding to an organophosphorus compound. We employed density functionaltheory (DFT), implicit methods for describing the water solvent, anda path integral approach to calculate fluorescence rates and emissionspectra from first-principles for analyzing the interaction betweenthe nerve agent simulant diethyl chlorophosphite (DCP) and NMU-1 orHBQ-AE. Upon interacting with DCP, both HBQ-AE and NMU-1 experiencestrong fluorescence quenching, with intensity reductions of ∼99.65and ∼99.95%, respectively, due to enhanced CT induced by DCP’selectron-accepting nature and formation of a positively charged nitrogenwithin the probes. Although the measured fluorescence enhancementin HBQ-AE/DCP systems was attributed to the HBQ-DCP product, our resultsshow a different picture: the true fluorescent species is the hydrolysisproduct HBQ + H, whose calculated emission differs by a blue shiftof only 0.23 eV from the experimental data, rather than the HBQ-DCPproduct as previously thought. For acetylcholinesterase (AChE) detection,fluorescence is confirmed to originate from the HBQ-Keto, with a blueshift deviation of 0.12 eV. The NMU-1 calculations also confirm theexperiments, showing a 0.24 eV deviation, thus confirming its quenching-baseddetection of DCP. Therefore, HBQ-AE is a fluorescence turn-on sensorvia its emissive hydrolysis product HBQ+H. In contrast, NMU-1 is aturn-off sensor, as both NMU-DCP and NMU+H are essentially nonemissive.Our theoretical approach is general, accurate, and can be appliedto different problems involving fluorescent probes and binding agents.

Abstract: For many applications, such as vests or parts of vests, the fibers are used in fabric, mat, or mesh. Ballistic resistance properties are also improved by the development of special fabrics architectures. It is known that heat and oxygen are the main factors in the aging process of polymers. The mechanisms of aging by oxidation can be investigated by monitoring the mechanical properties of a material exposed to prolonged aging in an oven, which is called the accelerated aging process by thermal oxidation. In previous studies, the epoxy matrix composite reinforced with 40% by volume of fique fabric, already tested and with good ballistic performance, was developed and proposed for individual ballistic protection applications. However, the impact of different environmental conditions on the dynamic properties of the composite has not been studied. Therefore, the present study, for the first time, aimed to apply accelerated weathering through high temperature to the composite, as well as to the epoxy matrix, aiming to evaluate the influence of aging.

Polymethylmethacrylate (PMMA) maxillofacial prostheses are widely used in facial bone reconstruction, providing functional restoration, aesthetic rehabilitation, and improved quality of life. However, due to its bioinert nature, PMMA exhibits limited tissue integration. This study aimed to coat PMMA maxillofacial prostheses with hydroxyapatite (HA) to enhance the material’s bioactivity and interaction with biological tissues. Two porous configurations fabricated by additive manufacturing were tested: Prototype A, with ellipsoidal pores, and Prototype B, with a regular hexagonal architecture. Mechanical evaluation demonstrated average values of 33.01 MPa for tensile strength, 3.18 MPa for impact toughness, and 62.65 MPa for flexural strength, confirming structural stability under functional demands. Structural analysis revealed the formation of calcium phosphate phases with low crystallinity, predominantly hydroxyapatite and octacalcium phosphate, while surface examination showed a continuous granular coating with pseudo-spherical agglomerates. Bioactivity assays indicated that the HA-coated prostheses were capable of inducing apatite precipitation, in contrast to uncoated PMMA, which remained bioinert. Prototype A favored permeability and surface area for potential cell adhesion, whereas Prototype B ensured uniform porosity and predictable load distribution. The integration of controlled porous architecture with HA deposition resulted in composite prostheses that combined mechanical robustness with surface bioactivity, representing a promising approach for improved maxillofacial reconstruction.

The aim of this study was to isolate and identify bioactive compounds through a bioactivity-guided analysis of extracts from Streptomyces strains. A bioactive extract from a Streptomyces species isolated from Amazonian soil, identified as S. collinus Tü 365 through the 16S rRNA and 23S rRNA genes, was selected for the study. The fermentation broth extract was partitioned and the bioactive fractions were further fractionated using chromatographic techniques (preparative TLC and HPLC). Through bioautography-guided fractionation, two actinomycins (D and X2) were isolated and identified by spectrometric (ESI-HRMSMS) and spectroscopic (NMR) techniques. The isolated substances were tested in the agar disc diffusion assay (Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis and Escherichia coli) and by the microdilution method in microplates (Staphylococcus aureus and Mycobacterium smegmatis). Actinomycins D and X2 showed activity against M. smegmatis 16.0 μg/mL for both samples and against S. aureus, 1 μg/mL and 0.5 μg/mL, respectively.

Eperua oleifera Ducke, commonly known as "copaíba-jacaré," produces oilresins traditionally used in folk medicine for wound healing and as antifungal and antibacterial agents, similar to those of Copaifera species. However, its chemical composition remains poorly characterized. This study investigated the oilresin of E. oleifera collected in the Brazilian Amazon region. After derivatization, the sample was analyzed by GC-MS, with data compared to literature, mass spectral libraries, and standards previously isolated. In addition, neutral and acidic fractions were separated using ion-exchange open-column chromatography with silica modified with KOH-impregnated silica as the stationary phase. Twelve diterpenes were identified, including nine carboxylic acids and three alcohols. Hardwickiic acid and copalic acid were the major components, fully characterized by NMR. The most abundant compound in the neutral fraction was isolated and identified by HRMS and NMR as the methyl ester of hardwickiic acid-a compound not previously reported in oilresins. The application of GC-MS enabled the identification of diterpenes based on known fragmentation patterns. In addition, the direct infusion experiment detected a methyl ester that, to our knowledge, has not been previously reported in oilresins.

While advances in material improvement are significant, actual adoption still depends on balancing cost, environmental impact, and performance. High-specification chemicals and complex processes can increase production costs, and the sustainability of new, partially synthetic systems must be examined. In this context, this study explored an alternative approach for agglomerated rocks, where the use of coupling agents enhances interface engineering. We addressed the mineral-polymer relationship by comparing two epoxy resins and two polyester resins with and without silane-based coupling agents (γ-APS for epoxies; MPTS for polyesters) in 85% by weight of granite waste. Original contributions include: a mix design selection (simplex network) for the densest packing (grain size: 66% coarse, 17% medium, 17% fine) by vibrated bulk density, validated via ANOVA/Tukey; a unified manufacturing route using vibropressing, vacuum compaction, and vacuum hot pressing (600 mmHg, 10 MPa, 90 °C). Physical indices (bulk density, open porosity, and water absorption) were evaluated in accordance with ABNT NBR 15845-2. Three-point bending tests were performed using ABNT NBR 15845-6 (for slabs) and ASTM D790 (for neat resins). Thermal behavior and fracture micromechanics were assessed through TGA/DSC (ASTM D6370) and SEM. Silanes increased bulk density and drastically reduced porosity and water absorption (by 61% and 84%, respectively), while increasing flexural strength by 16–38% in all resin families; neat epoxy with γ-APS also showed substantial strengthening. TGA indicated a higher onset of degradation and lower mass loss; SEM showed more cohesive fracture, consistent with siloxane anchoring to silicates and amine-epoxy or thiol-ene reactions. By combining particle packing optimization with targeted interfacial chemistry at moderate processing temperatures, the approach confirms the goals of agglomerated rock, such as improved qualities while mitigating the costs and environmental impacts associated with conventional designs that require higher resin percentages.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-18783-4.

Eperua oleifera Ducke (Fabaceae), commonly known as copaíba-jacaré, is traditionally used for therapeutic purposes, like Copaifera oleoresins. Previous GC-MS studies reported its chemical composition as mainly composed of diterpenic acids, consistent with species of the same genus. Although GC-MS remains widely used for comparing compound retention times and fragmentation patterns, its application to diterpenic acids requires a derivatization step to form methyl esters due to the poor chromatographic performance of carboxylic acids on methyl silicone stationary phases. This step may lead to misinterpretations, especially considering recent findings of naturally occurring methyl esters in oleoresins that may co-elute with derivatized acids. This study aimed to apply more sensitive analytical techniques to identify both target and untargeted compounds. The resin of E. oleifera was analyzed by GC-MS to assess the presence of volatile components. Additionally, UHPLC-HRMS was employed using full-scan MS, data-dependent acquisition (DDA), and parallel reaction monitoring (PRM) in both positive and negative ESI modes. GC-MS confirmed the absence of volatile sesquiterpenes, classifying E. oleifera as a resin. Targeted UHPLC-HRMS detected natural methyl esters of diterpenic acids, while untargeted analysis using Compound Discoverer 3.3 software revealed flavonoids and phenolic compounds not previously reported. These findings support the application of UHPLC-HRMS as a powerful tool in phytochemical studies.