Search Results (4,507)

To address heavy metal contamination in wastewater, this study developed a novel chelating resin (PS-2-AB) by grafting 2-aminobenzimidazole onto chloromethylated polystyrene. The resin was characterized using SEM, BET, FTIR, and XPS to confirm successful modification and analyze its structural properties. Batch adsorption tests were conducted to evaluate its removal performance for Cu(II) and Ni(II) ions. Under optimal conditions (pH 5.0–7.0, dosage: 1.0 g/L), PS-2-AB achieved maximum adsorption capacities of 125.04 mg/g for Cu(II) and 157.44 mg/g for Ni(II), which are significantly higher than those of the commercial resin D113 (44.68 mg/g for Cu(II) and 25.17 mg/g for Ni(II)) under the same conditions. Adsorption kinetics followed the pseudo-second-order model, indicating chemisorption-dominated behavior, while equilibrium data fit the Langmuir model, suggesting monolayer adsorption. Thermodynamic parameters confirmed a spontaneous and endothermic process. After five regeneration cycles, PS-2-AB retained approximately 87% (Cu) and 89% (Ni) of its original capacity, demonstrating good reusability. These results indicate that PS-2-AB exhibits markedly better adsorption performance than D113, making it a promising and cost-effective adsorbent for the efficient removal of Cu(II) and Ni(II) from aqueous media. Full article

This study evaluated the iron-chelating capacity (ICC) of Lupinus mutabilis protein hydrolysate (LMPH) and its peptide fractions obtained through ultrafiltration and purification by immobilized metal ion affinity chromatography (IMAC) and gel filtration chromatography (GFC). Peptides were identified by LC-MS/MS, and their interactions with Fe²⁺ were analysed using molecular docking. LMPH was produced by enzymatic hydrolysis with Alcalase and subsequently subjected to ultrafiltration to concentrate peptides smaller than 2 kDa. This fraction exhibited higher ICC (35.1 mg Fe²⁺·g⁻¹) than the hydrolysate (22.75 mg Fe²⁺·g⁻¹). Sequential purification by IMAC and GFC yielded peptide fractions with enhanced ICC values (45.20 and 13.51 mg Fe²⁺·g⁻¹). A total of 176 peptides were identified by de novo LC-MS/MS sequencing, from which nine were selected based on favourable structure–ICC relationships and absence of predicted toxicity. Molecular docking analysis suggested spatial proximity between Fe²⁺ and the selected peptides. Although stable multi-site binding was not predicted under the applied computational model, the results support the potential of these sequences to interact with Fe²⁺. These findings provide molecular and chemical insights supporting the iron-binding potential of LMPH-derived peptides and highlight their future potential as functional ingredients for preventing and managing iron deficiency. Full article

Ostericum palustre (Besser) Besser (synonym Angelica pancicii Vandas ex. Velen.) is a Eurasian species from the Apiaceae family, previously related to the Balkan endemic species A. pancicii. The study aims to provide a thorough profiling of methanol-aqueous extracts from O. palustre leaves, roots, and inflorescences integrated with an evaluation of antioxidant potential and enzyme inhibitory activity towards some therapeutic targets. For the first time, a series of simple coumarins and furanocoumarins alongside phenolic and acylquinic acids, and flavonoids were annotated/dereplicated in the O. palustre of Bulgarian origin by liquid chromatography coupled with quadrupole—Orbitrap high resolution mass spectrometry acquisition platform. According to the discriminant analysis (sPLS-DA) of the biological potential, radical scavenging activity (47.9 mg TE/g in DPPH and 61.8 mg TE/g in ABTS), reducing power (102.2 mg TE/g in CUPRAC and 57.4 mg TE/g in FRAP), and metal-chelating capacity (20.1 mg EDTAE/g) accounted mainly for the stronger antioxidant activity of inflorescences extract than roots and leaves. Root extracts exhibited anti-collagenase, anti-elastase, and anti-hyaluronidase effects with lower IC₅₀ values (IC₅₀ 37.22, 42.47 and 32.09 μg/mL, respectively). Pearson relationship analysis revealed potent antioxidants including furanocoumarins (oxypeucedanin hydrate, xanthotoxol/bergaptol, byakangelicin/isobyakangelicin, ostruthol) and phenolic acids, while a series of angelols alongside feruloylquinic and dicaffeoylquinic acids, and flavonol glycosides hold significance for the neuroprotective activity of the leaves extract. The enzyme inhibitory activity of the root extracts towards collagenase, elastase and hyaluronidase, related to the anti-aging activity, was ascribed to simple hydroxylated/methoxylated coumarins. The study suggests the potential health benefits of O. palustre extracts as antioxidant, anti-aging, and neuroprotective agents. Full article

Picnomon acarna (L.) Cass. is a Mediterranean medicinal plant with limited phytochemical and bioactivity characterisation. In this study, methanolic extracts obtained by maceration (MAC), Soxhlet (SOE), and ultrasound-assisted extraction (UAE) were comparatively investigated to determine their phytochemical composition and biological potential. Liquid chromatography–electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis identified and quantified 24 phenolic compounds, with hesperidin, chlorogenic acid, and hyperoside as the dominant constituents. The maceration extract exhibited the highest total phenolic content (29.06 mg GAE/g extract) and showed superior antioxidant performance across six complementary assays [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), phosphomolybdenum, and ferrous-ion chelation), reflected by the highest relative antioxidant capacity index (RACI = 0.93). Enzyme inhibition assays revealed extraction-dependent activity patterns: Soxhlet and ultrasound extracts demonstrated stronger acetylcholinesterase inhibition (IC₅₀ ≈ 1.23 mg/mL), while Soxhlet extract showed the most potent tyrosinase (AChE) inhibition (IC₅₀ = 1.48 mg/mL). α-Amylase inhibition was comparable among extracts (IC₅₀ = 1.90–2.03 mg/mL). Pearson correlation analysis indicated strong relationships between major phenolics and antioxidant activity. Molecular docking further supported these findings, showing favourable binding affinities of hesperidin, hyperoside, and chlorogenic acid toward α-amylase and acetylcholinesterase, while only chlorogenic acid and hyperoside demonstrated favourable interactions with tyrosinase-related protein-1 (TYRP1), whereas hesperidin did not exhibit a meaningful binding affinity. Overall, the results demonstrate that the extraction strategy significantly influences the phenolic composition and multi-target bioactivity of P. acarna, highlighting its potential as a source of natural antioxidant and enzyme-modulating compounds. Full article

Cadmium (Cd) is a potentially toxic element that impairs plant growth and threatens food safety and human health. This study aimed to investigate the effects of sulfur (S) supplementation on Cd uptake and tolerance in rice under hydroponic conditions. Rice seedlings were exposed to Cd stress and treated with S at different concentrations. Physiological traits, oxidative damage markers, thiol compounds, and ionomic profiles in rice plants were assessed. S supplementation reduced Cd-induced growth inhibition, restoring plant biomass. Although Cd accumulation increased with S treatment, it was accompanied by enhanced antioxidant responses, scavenging reactive oxygen species (ROS) and malondialdehyde. S application increased the production of thiol-containing compounds, including γ-glutamylcysteine, glutathione, and phytochelatins, which helped chelate Cd and sequester it in vacuoles, particularly in roots. Additionally, S supplementation altered the essential nutrient composition in rice tissues, particularly the uptake of N, P, and K, while influencing levels of Ca, Mg, and other essential elements. S supplementation enhanced rice tolerance to Cd stress by reestablishing ROS balance, activating thiol-based detoxification pathways, and regulating mineral nutrient balance. Furthermore, sulfur (S) exhibited a dual effect in plants, enhancing cadmium (Cd) uptake while also promoting its detoxification, underscoring its role in improving crop resilience in contaminated soils. Full article

Ferroptosis is an iron-dependent cell death driven by lipid peroxidation and failure of cellular antioxidant defenses. It is triggered by oxidative stress and can be aggravated by aging, inflammation, and dysregulation of iron homeostasis. In the central nervous system, iron dyshomeostasis, mitochondrial dysfunction, and membrane lipid remodeling can amplify oxidative injury and increase susceptibility to ferroptotic damage, particularly in vulnerable neurons. There is growing evidence that ferroptosis-related processes are linked to Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and Amyotrophic Lateral Sclerosis. This review addresses novel approaches to track ferroptosis in vivo, such as imaging and biomarker techniques, and important molecular mechanisms linking iron metabolism, reactive oxygen species, and PUFA-driven lipid peroxidation to neuronal damage. We also explore upstream transcriptional control via NRF2, iron chelation and iron-handling modulation, inhibition of lipid peroxidation, and reinforcement of the System Xc-GSH-GPX4 and CoQ10-linked defense pathways. Subsequently, we highlight translational issues that need attention to further progress ferroptosis-targeted therapies for neurodegenerative disease. Full article

Background: Campylobacter jejuni, a leading foodborne pathogen in poultry, relies heavily on iron for survival and colonizes the gastrointestinal tract (GIT). Iron supplementation in poultry diets can inadvertently promote pathogen growth, particularly when excess or poorly absorbed iron accumulates in the lower GIT. Encapsulated iron products, such as SQM^® Iron, offer a controlled-release mechanism that may mitigate this risk by reducing iron availability to microbes. Objective: This study evaluated the effects of free (FeSO₄) versus polysaccharide–iron complex (PIC) on C. jejuni growth under iron-limited conditions, hypothesizing that encapsulated iron would support slower and more limited bacterial proliferation due to delayed iron release. Methods: Growth kinetics of C. jejuni ATCC 700819 were assessed in chelated Mueller–Hinton broth supplemented with three iron concentrations (10, 20, and 50 ppm) of FeSO₄, PIC, or PIC matrix without iron. Optical density was measured every 20 min over 48 h under microaerophilic conditions. Maximum growth rate (µmax) and carrying capacity (K) were derived using non-linear curve modeling. ANOVA evaluated statistical significance with Tukey’s HSD post hoc comparisons. Results: Free iron (FeSO₄) consistently supported the highest µmax and K values across both trials, indicating rapid and robust C. jejuni proliferation. The effect of encapsulated iron was variable: at higher concentrations (50 ppm) it approached FeSO₄ performance, but at lower concentrations (10 ppm) its effect differed markedly between trials, sometimes supporting growth comparable to free iron and sometimes supporting substantially slower growth. The PIC matrix alone did not promote growth. These variable results indicate that the relationship between encapsulated iron and C. jejuni proliferation is complex and concentration-dependent. Conclusions: Free iron consistently promotes robust C. jejuni growth due to immediate bioavailability. The impact of encapsulated iron on C. jejuni proliferation is nuanced and variable, particularly at lower concentrations, suggesting its role in pathogen control is not straightforward and requires further investigation under controlled conditions. Furthermore, in vivo research is warranted to validate its utility in poultry pathogen management strategies. Full article

Bidentate ligands, derived from the 1,3-dicarbonyl framework, play a central role in coordination chemistry, catalysis, and materials science due to their tuneable donor properties and structural versatility. This review examines and compares three closely related ligand classes, β-diketones (O,O′ donors), imino-β-diketones or enaminones (N,O donors), and di-imino-β-diketones or β-diketiminates (N,N′ donors), to elucidate how systematic substitution of oxygen by nitrogen affects structure and properties. The discussion integrates spectroscopic data (NMR and IR), crystallographic findings, electrochemical measurements, and density functional theory (DFT) calculations reported in the literature. Across these systems, tautomerism plays a decisive role, with conjugation-stabilized enol or enamine forms generally preferred in solution and the solid state. Frontier molecular orbital analyses show extensive delocalization over the chelate backbone and, when present, aromatic substituents. Electrochemical studies reveal consistent correlations between experimental reduction potentials and calculated LUMO energies for O,O′-, N,O-, and N,N′-bidentate ligands. Overall, the comparison demonstrates that donor atom substitution within a conserved conjugated scaffold provides a systematic approach to tuning acidity, coordination behaviour, and redox properties, offering a coherent framework for understanding structure–property relationships in 1,3-dicarbonyl-derived chelating ligands. Full article

The invasive brown macroalga Rugulopteryx okamurae has rapidly expanded across the Mediterranean–Atlantic region, generating severe ecological impacts. Nevertheless, the considerable amount of biomass available creates opportunities for valorisation within circular bioeconomy frameworks. This study provides an integrated characterization of the chemical profile and bioactivities of freshly collected floating biomass of R. okamurae from southern Portugal. Proximate composition was determined, and lipophilic (hexane) and hydrophilic (water) extracts were analyzed by GC–MS and spectrophotometric methods. Antioxidant activity was assessed using complementary radical-scavenging, reducing power, and metal-chelation assays, and enzyme inhibition was evaluated against targets associated with neurodegenerative, metabolic, and dermatological disorders. The lipophilic fraction was dominated by long-chain alkanes (≈101 mg/g extract) and sterols, particularly fucosterol (≈43 mg/g extract), but exhibited low radical-scavenging capacity (no EC₅₀ reached in DPPH or ABTS assays), and no relevant enzyme inhibition. In contrast, the water extract contained measurable phlorotannins (6.61 mg PGE/g extract) and showed moderate antioxidant (ABTS: EC₅₀ = 5.17 mg/mL; FRAP: EC₅₀ = 0.78 mg/mL) and enzyme inhibition activities (BChE: IC₅₀ = 5.17 mg/mL; tyrosinase: IC₅₀ = 0.78 mg/mL). Compared with previous studies on R. okamurae, this work applies a systematic fractionation of biomass from southern Portugal into polar and non-polar fractions and, for the first time, correlates the resulting detailed chemical profiles with multiple bioactivities. This approach revealed a clear functional differentiation between fractions, with bioactivity being mainly associated with polar metabolites. Overall, these findings highlight the value of structured extraction strategies for biomass valorisation and support the sustainable management of R. okamurae. Full article

Gold nanoparticles (AuNPs) have been extensively studied in cancer treatment research since they have special physicochemical characteristics such as facile surface functionalization with various chemical groups, low toxicity, favorable biocompatibility, and the ability to passively accumulate in tumors through the enhanced permeability and retention (EPR) effect. Prostate cancer cells exhibit an overexpression of the Prostate-Specific Membrane Antigen (PSMA), which therefore represents an ideal candidate for the development of nanoplatforms targeting PSMA overexpressed on these cells. Lutetium-177 (¹⁷⁷Lu) is a β-particle emitter with a half-life of 6.7 days. This radionuclide is very promising for the development of theranostic platforms as it emits β⁻ particles, which are suitable for therapy, and γ-photons, capable of SPECT imaging. The combination of ¹⁷⁷Lu with AuNPs functionalized with PSMA for targeted delivery offers a promising tool for both diagnosis and therapy of prostate cancer. In this study, we focused on the synthesis and in vitro evaluation of PSMA-targeted AuNPs radiolabeled with ¹⁷⁷Lu. The AuNPs were functionalized with the TADOTAGA chelator, which enables effective radiolabeling with the radiometal, as well as with a PSMA molecule, which comprises the PSMA targeting moiety (vehicle) of the nanoconstruct. Radiolabeling of the functionalized AuNPs with ¹⁷⁷Lu was fast and robust. Subsequent studies focused on the in vitro stability and cellular interaction with two prostate cancer cell lines with different PSMA expression levels, in both 2D and 3D cell cultures, to assess effective targeting. Results indicate that radiolabeled AuNPs exhibit selective interaction with PSMA-expressing cells and present a stronger in vitro cytotoxic effect when functionalized with the PSMA molecule, confirming their potential as theranostic agents and warranting further investigation in LNCaP tumor-bearing mice. Full article

Normal steps in uptake of non-heme iron by the gastrointestinal tract include ferrireduction and import across the apical enterocyte membrane by divalent metal transporter 1 (DMT1), responsible for the uptake of non-transferrin bound iron (NTBI). This metal import by the intestinal epithelium requires an acidic milieu generated by the proton pump H(+)/K(+) ATPase (ATP4). Gastrointestinal uptake of metal can be affected by altering the acid milieu (e.g., proton pump inhibitors). After metal uptake by enterocytes, ferroxidation and export of the metal by ferroportin (FPN) at the basolateral membrane leads to the export of iron bound to transferrin (Tf). In peripheral tissues, cellular uptake of circulating iron is mediated by receptor-mediated endocytosis of Tf-bound iron, with DMT1 transporting the metal out of the endosomal compartment under acidic conditions generated by the vacuolar H⁺-ATPase. Acidosis is frequently associated with inflammation. The two derangements have relevant consequences like improved solubilization of iron, increased expression of Dmt1, elevated Fe²⁺ uptake due to DMT1’s ability to cotransport H⁺, dissociation of Fe-Tf and hepcidin decreasing Fe export via FPN. These changes result in intracellular iron sequestration that frequently becomes noxious. Pharmacological strategies to inhibit NTBI transport are proposed to protect against iron overload associated with acidosis and inflammation. Full article

To reduce staining, paper conservators have increasingly treated artworks on paper with enhanced washing using chelating agents, which form complexes with metallic ions, thus facilitating the removal of stains. However, questions remain regarding the efficacy of the method and its impact on the long-term preservation of paper. A treatment of enhanced washing was undertaken on a nineteenth-century mezzotint printed using the chine collé technique, by David Lucas after a painting by John Constable, which was disfigured by significant foxing stains. This intervention provided the opportunity to investigate the mechanism and efficacy of the treatment and whether an alkali reserve could successfully be reintroduced. The print was analysed before, during, and after treatment with a Bruker M6 Jetstream scanning X-ray fluorescence (XRF) spectrometer. The results provided spatially resolved information on the effects of the treatment and gave new insights into the heavily debated causes of foxing on paper, challenging the link with iron contamination. Instead, the distribution of foxing stains showed a correlation with the presence of potassium and calcium, and their reduction during washing corresponded with an improvement in appearance. Calcium replenishment proved only partially successful. Finally, scanning XRF has rarely been used for the analysis of artworks on paper; this study proves its value for research. Full article

Microplastics can bind with toxic metals via surface complexation and chelation, forming combined pollutants. However, research regarding the toxicological impacts of these combined pollutants on soil fauna remains limited. This study employed Folsomia candida in a 28-day incubation experiment to investigate the ecotoxicological effects of combined pollution by polylactic acid microplastics (PLA-MPs) and thallium (Tl) on the functional traits of Folsomia candida, including biology, morphology, and gut microbiota. The results showed that the combined effects of PLA-MPs and Tl on these functional traits were characterized by amplified toxicity and trait-specific responses. Morphological traits exhibited lower sensitivity to the pollution treatments compared to other indicators. Exposure to high-concentration PLA-MPs (10%) significantly affected mortality and fecundity, and reduced gut bacterial diversity. Conversely, low-concentration Tl (1 mg/kg) significantly inhibited body length and antenna length while increasing gut bacterial diversity. Structured equation modeling further revealed that the pollution treatments exerted significant negative effects on the functional traits of Folsomia candida, both directly and indirectly by altering soil properties and soil microbiota. These findings provide valuable insights into the ecotoxicological effects of combined PLA-MPs and Tl pollution on soil fauna, contributing to ecological health risk assessments of microplastics and toxic metals in terrestrial ecosystems. Full article

Ethylene–propylene–diene monomer rubber (EPDM) is commonly used as a gas-tight sealing material in electrical equipment. Factors such as media exposure, thermal oxidative stress, and abrasion frequently cause deterioration of EPDM’s mechanical properties, significantly compromising the reliability of electrical equipment. Traditional activator ZnO provides limited enhancement to the properties of EPDM. The reaction between Zn²⁺ on the surface of zinc oxide interacts with the accelerator during curing of rubber, forming zinc chelates, which interact with sulfur to form zinc polysulfide complexes. But the release of zinc complexes has adverse effects on humans and ecosystems. To reduce ZnO usage and further improve the performance of EPDM in terms of mechanical properties and aging resistance, zeolitic imidazolate framework-8 (ZIF-8) is developed as a multifunctional additive in this work. Mechanical testing demonstrates that the incorporation of ZIF-8 enhances the mechanical performance and resistance to thermal oxidative aging of EPDM. Crosslink density testing, FTIR, and XPS show that ZIF-8 promotes the crosslinking reaction during rubber curing, resulting in improved mechanical performance for EPDM. Analysis of crosslinking density testing and SEM images shows that EPDM-ZIF-8 composite exhibits a slower increase in crosslinking density during thermal oxidative aging. TGA results indicate that ZIF-8 enhances the thermal stability of EPDM, which leads to improved aging resistance properties. This study provides new insights for the design and development of rubber composite materials, offering a reliable solution to the challenge of seal failure in electrical equipment. Full article

The use of one-step products and their applications in sensory applications has gained much importance. Herein, Schiff’s base fluorescent turn-on sensor, namely FBTS, was synthesised via a condensation reaction between 6-fluorobenzo[d]thiazol-2-amine and 2-hydroxybenzaldehyde. The probe FBTS exhibits an intense “turn-on” blue fluorescence upon binding to Al³⁺ ions in a dimethyl sulfoxide–water (DMSO–H₂O (8:2, v/v)) medium. From photoluminescence (PL) titrations, the detection limit (LOD) for Al³⁺ is estimated to be 0.14 microM, and the Benesi–Hildebrand plot-based association constant (K_a) of 5.4 × 10⁴ M⁻¹ confirm a strong association between FBTS and Al³⁺. Negligible interference is observed in the presence of other metal ions. From the pH effect studies, the optimal pH range for Al³⁺ detection is 7–9. The recyclable reversibility of FBTS + Al³⁺ complex has been demonstrated via the sodium salt of ethylenediaminetetraacetic acid (Na₂-EDTA) chelation. A Job’s plot and interrogations, such as high-resolution mass spectrometry (HR-MS), ¹H-nuclear magnetic resonance (NMR) titration, and density functional theory (DFT), verified the 1:1 stoichiometry of binding between FBTS and Al³⁺. Based on multiple analyses, the binding mode and mechanism have been detailed. In addition, the practical application of FBTS for detecting Al³⁺ is demonstrated using the strip paper method, fish analysis, spiked real sample analysis, and cellular imaging. Full article