Search Results (9,816)

Background: Alzheimer’s disease (AD) is largely linked with oxidative stress, the accumulation of amyloid-β plaques, and hyperphosphorylated τ-protein aggregation. Alterations in dopaminergic and serotonergic neurotransmission have also been implicated in various AD-related symptoms. Methods: To explore new therapeutic agents, a series of bicyclic and tricyclic thieno-oxazepine derivatives were synthesized as potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The resultant compounds were purified via HPLC and characterized using spectral analysis techniques. Histopathological examinations, other antioxidants, and anti-inflammatory biomarkers were evaluated, and in silico ADMET calculations were performed for synthetic hybrids. Molecular docking was utilized to validate the new drugs’ binding mechanisms. Results: The most powerful AChE inhibitors were 14 and 16, with respective values of IC₅₀ equal to 0.39 and 0.76 µM. Derivative 15 demonstrated remarkable BChE-inhibitory efficacy, on par with tacrine, with IC₅₀ values of 0.70 µM. Hybrids 13 and 15 showed greater selectivity towards BChE, despite substantial inhibition of AChE. Compounds 13 and 15 reduced escape latency and raised residence time, with almost equal activity to donepezil. Conclusions: According to these findings, the designed hybrids constitute multipotent lead compounds that could be used in the creation of novel anti-AD medications. Full article

The existence of dissolved organic matter (DOM) in aquatic environments presents significant challenges to both the environment and public health. This study examines the adsorption efficacy of six organic adsorbents, such as three commercial (coconut shells [CS], palm kernel shells [PKS], and graphite [GR]) and three waste-based materials (plantain peels [PP], water hyacinth leaves [WHL], and corn cobs [CC]) for DOM removal. The waste-derived adsorbents were prepared using thermal and chemical activation techniques, while the commercial adsorbents were used in their standard forms. Adsorption experiments were conducted and analyzed using both kinetic and isotherm models to evaluate removal efficiency and underlying mechanisms. Kinetic modeling revealed that CS, PP, CC, and GR followed pseudo-second-order kinetics, PKS conformed to pseudo-first-order kinetics, and WHL exhibited intra-particle diffusion dominance. The Freundlich isotherm model effectively characterizes the adsorption equilibrium for every material, indicating the multilayer adsorption and heterogeneity of the adsorbent surfaces. Among all tested materials, GR showed the highest DOM removal efficiency (up to 96%) and excellent thermal stability, making it the most effective adsorbent overall. WHL also showed competitive performance, while CS emerged as the most economically viable option despite having slightly lower removal efficiency. Surface area alone does not guarantee adsorption efficiency. Pore accessibility (governed by size/distribution) and surface chemistry (functional group diversity) are equally critical. The findings suggest that both commercial and waste-derived adsorbents hold promise for sustainable and cost-effective water treatment applications. Integrating such materials could enhance the circular economy and offer scalable solutions for addressing water quality issues in developing regions. Full article

Human fungal infections comprise systemic mycoses as well as various skin diseases. Rising case numbers along with inefficient therapies and the appearance of drug-resistant strains unleashed a considerable health problem over the last years. Thus, the identification and development of new antifungal drugs is mandatory, which can include the design of new antifungals, or, more time saving, the repurposing of known drugs already applied for the therapy of other human diseases. The orally applicable gold-based drug auranofin has been used for the treatment of rheumatoid arthritis since the 1980s. However, auranofin also showed marked activity against various cancers, microbes, parasites, and viruses. Facing a pressing need to find new drug candidates against mycoses, especially against those listed in the WHO fungal pathogen priority list, we have summarized the eminent antifungal activities of auranofin in this review. Given its established safety profile and broad-spectrum activity, auranofin represents a promising candidate for repurposing in antifungal therapy. The mechanism of action of auranofin was correlated with thioredoxin reductase inhibition, but other modes of action such as interference with mitochondrial protein import and NADH kinase were also described and discussed. A selection of promising antifungal gold complexes was also provided. Pertinent literature is covered until 2025. Full article

Novel polyester–polyurethane polymeric materials were formulated by combining a natural aliphatic polyester, poly(3-hydroxybutyrate) (P3HB), with a synthetic aliphatic polyurethane via melt blending. The resulting fully biodegradable compositions were functionally modified through the incorporation of urea, with the aim of enabling post-consumer utilization of the material residues as nitrogen-rich fertilizers. The fabrication process was systematically established and optimized, focusing on homogeneous blending and processability. Comprehensive mechanical characterization—including tensile strength, impact resistance, and Shore hardness—was performed. Among the tested formulations, composites containing 1 wt.% urea demonstrated superior mechanical performance and optimal processing behavior. Fourier-transform infrared (FTIR) spectroscopy was employed to investigate molecular-level interactions between polymeric phases and urea, while scanning electron microscopy (SEM) was utilized to assess the morphological characteristics of the resulting biocompositions. Comparative analyses of the physico-mechanical properties and biodegradability were conducted among the urea-modified compositions, binary P3HB–polyurethane blends, and neat P3HB. The observed improvements in mechanical integrity and functional biodegradability suggest that the developed urea-enriched compositions are promising candidates for the fabrication of eco-friendly seedling pots via injection molding technology. Full article

The aim of this paper is to obtain ethyl (2-(methylcarbamoyl)phenyl)carbamate and its metal complexes as promising antimicrobial agents. The title compound was synthesized using the ring-opening of isatoic anhydride with methylamine and further acylation with ethyl chloroformate. All metal complexes were successfully obtained after mixing the ligand dissolved in DMSO and water solutions of the corresponding metal salts and sodium hydroxide, in a metal-to-ligand-to base ratio 1:2:2. As a result, mixed ligand complexes of ethyl 2-(methylcarbamoyl)phenyl)carbamate and 3-methylquinazoline-2,4(1H,3H)-dione were obtained. The obtained complexes were characterized by their melting points, FTIR, NMR spectroscopy, and MP-AES. Then, the antimicrobial effect of the compounds against both Gram-negative and Gram-positive bacteria, yeasts, and fungi was studied. Only the Co(II) complex showed antimicrobial activity against almost all Gram-positive and Gram-negative bacteria. The cobalt complex exhibited promising antimicrobial activity against Gram-positive Micrococcus luteus with inhibition zones of 20 mm, Listeria monocytogenes (15 mm), Staphylococcus aureus (13 mm), as well as Gram-negative Klebsiella pneumoniae (13 mm) and Proteus vulgaris (13 mm). Given the potential of metal complexes as antimicrobial agents, understanding their cytotoxic effects is crucial for evaluating their therapeutic safety. To assess the in vitro biocompatibility of the experimental compounds, a range of cell viability assays was conducted using human malignant leukemic cell lines (LAMA-84, K-562) and normal murine fibroblast cells (CCL-1). The Ni(II) complex shows IC₅₀ = 105.1 µM against human malignant leukemic cell lines LAMA-84. Based on the reported results, it may be concluded that the mixed cobalt complex of 2-(methylcarbamoyl)phenyl)carbamate and 3-methylquinazoline-2,4(1H,3H)-dione can be attributed as a promising antimicrobial agent. Future in vivo tests will contribute to establishing the antimicrobial properties of this complex. Full article

The stereoselective synthesis of trisubstituted alkenes has become a key topic in modern organic chemistry. At the same time, trisubstituted alkenes also serve as valuable starting materials for a wide range of transformations. However, it remains unclear to what extent these alkenes are utilized in comparison to their mono- and disubstituted counterparts. This review aims to provide a comprehensive overview of fundamental transformations involving all-carbon-substituted trisubstituted alkenes. The first section focuses on additions of carbon, oxygen, and nitrogen nucleophiles, as well as halogenation and carboxylation reactions. The second part discusses oxidative cleavage processes, while the final section addresses the cyclization and cycloisomerization reactions of trisubstituted alkenes. Full article

Camelina (Camelina sativa L.) is a valuable source of seed oil, which contains above 30% of essential omega-3 fatty acid (alpha-linolenic acid, 18:3). On the one hand, this high content of linolenic acid is healthy and hence preferable, but on the other hand, highly unsaturated oils are easily deteriorated. The stabilization of such oils with respect to their oxidative changes is a significant problem in oil technology and is directly related to the quality of food, pharmaceutical and cosmetic products. Therefore, the aim of this work was to evaluate the effect of ascorbyl palmitate in various concentrations (0.1–2.0 mM) as an additional antioxidant in camelina seed oil during its autoxidation, by determination of oil induction periods and initial rates of oxidation. The results revealed that the added ascorbyl palmitate caused a decrease in oxidation rate, but in terms of oil stability, opposite effects were observed depending on its concentration. Thus, at low levels (0.1–0.2 mM), ascorbyl palmitate had a pro-oxidant effect and the induction period decreased; no effect was observed in its presence of 1.0 mM, whereas 2.0 mM ensured a much higher protective effect. Rosmarinic acid as an individual antioxidant (at 0.2 mM) increased the stability of camelina oil, while in a mixture (1:1) with ascorbyl palmitate at the same concentration, its effect/activity was significantly reduced. Full article

Advances in drug development continue to play a critical role in addressing diseases, including those with unmet medical needs. In 2024, the FDA approved 50 novel drugs, 16 of which were biologics. For context, during the first half of 2024 alone, the agency approved six biologics. By mid-2025, six additional biologics have received the green light, indicating that the pace of approvals of this class of drugs this year may be on par with 2024. This paper analyzes all biologics that received FDA authorization in 2024, examining their mechanisms, clinical trials, and expedited review pathways. Key approvals included the highest number of monoclonal antibodies (mAbs) since 2015 (13 mAbs, 6 indicated for oncology), while no antibody–drug conjugates were authorized—continuing with the trend in 2023. In addition, a new chimeric mAb has been approved since the last chimeric mAb approved in 2022, and a new mAb for Alzheimer’s disease. Nine biologics are first-in-class therapies, while ten received Orphan Drug Designation. The biologics considered herein fall into the categories of mAbs and proteins. Full article

Inspired by naturally occurring bis-isochromans such as penicisteckins, we envisaged the first synthesis of biaryl-type bis-1-arylisochromans containing a stereogenic ortho-trisubstituted biaryl axis. We achieved the stereoselective synthesis of 5,5′-linked heterodimeric bis-isochromans containing both central and axial chirality elements by performing diastereoselective Suzuki–Miyaura biaryl coupling reactions on two optically active 1-arylpropan-2-ol derivatives, followed by two oxa-Pictet–Spengler cyclizations with aryl aldehydes or methoxymethyl chloride. We studied the diastereoselectivity of the cyclization step, separated the stereoisomeric products with chiral preparative HPLC and determined the absolute configuration through a combination of vibrational circular dichroism (VCD), NMR and single-crystal X-ray diffraction analysis. We demonstrated that different aryl groups could be introduced into the two isochroman subunits, since the dimethoxyaryl subunit reacted faster, enabling the two oxa-Pictet–Spengler cyclizations to be performed separately with different aryl aldehydes. We also explored the acid-catalyzed isomerization and oxidation to axially chiral ortho-quinones in order to produce stereoisomeric and oxidized analogs, respectively. We identified the antibacterial activity of our target bis-isochromans against Bacillus subtilis and Enterococcus faecalis with minimum inhibitory concentrations down to 4.0 and 0.5 μg/mL, respectively, which depend on the stereochemistry and substitution pattern of the bis-isochroman skeleton. Full article

Background: In adhesive dentistry, debonding-on-demand is attractive for situations where no permanent attachment is required. Due to its destructive nature, ultraviolet (UV) light may be of interest for attenuating bond forces. The aim of this study was to investigate the impact of UV light on the shear bond strength (SBS) of etch-and-rinse (n = 4) and universal adhesives (n = 3). Methods: Glass-ceramic samples were bonded to bovine enamel surfaces (n = 10/adhesive) and subjected to shear bond testing before and after exposure to UV light (320–390 nm, 126 Jcm⁻²). Data was statistically analyzed by Mann–Whitney U test. Results: Initial photopolymerized etch-and-rinse adhesives showed superior SBS compared to universal adhesives. Highest values were recorded for iBOND^® Total etch (15.48 MPa) and Syntac classic© (17.60 MPa). Lowest SBS was obtained for Ecosite Bond^® (2.63 MPa). Additional UV exposure caused a significant decrease in SBS among iBOND Total etch (5.24 MPa, p = 0.009) and Solobond M© (3.65 MPa, p = 0.005), while for Syntac classic©, an increase (24.12 MPa, p = 0.047) was recorded. Among all other tested adhesives, no significant changes were observed. Conclusions: UV radiation impacted SBS of etch-and-rinse adhesives only (decrease: iBOND Total Etch, Solobond M; enhancement: Syntac classic©). Further research should focus on introducing sufficient light-triggered debonding mechanisms. Full article

The search for new antimicrobial agents is one of the major challenges in contemporary medicinal chemistry due to the global issue of increasing drug resistance. In our efforts to identify chemical structures with antibiotic activity that differ from commonly used antibiotics, we focused our research on (thio)semicarbazides and hydrazones. Guided by literature reports, we designed and synthesized a series of novel semicarbazides, thiosemicarbazides, and hydrazones based on the structure of 4-(morpholino-4-yl)-3-nitrobenzohydrazide. The obtained derivatives were subsequently evaluated in in vitro assays for their activity against reference strains of Gram-positive and Gram-negative bacteria. Among the studied groups of compounds, the semicarbazide derivatives exhibited the highest activity. The most active compound identified in the study was a semicarbazide containing a 4-bromophenyl moiety. This compound showed antibacterial potential against Enterococcus faecalis, with a MIC value of 3.91 µg/mL. Among the thiosemicarbazides, the most active compound contained a 4-trifluoromethylphenyl group, with MIC values against Gram-positive bacterial strains (excluding Staphylococcus aureus) ranging from 31.25 to 62.5 µg/mL. None of the tested hydrazones exhibited antimicrobial activity against the examined bacteria. Additionally, the structures of the new compounds were confirmed by single-crystal X-ray analysis, which enabled the investigation of their properties using advanced quantum chemical calculations. Full article

As a rich source of biologically active compounds, pomegranate peel is a valuable by-product with applications in the food, pharmaceutical and cosmetic sectors. The present study aimed to investigate the phytochemical composition, antioxidant and antimicrobial activity, photoprotective activity and application in a cosmetic emulsion of extracts obtained from pomegranate peel by different solvents. The analysis of phenolic compounds was determined by high-performance liquid chromatography (HPLC); the total phenolic content (TPC) and the total flavonoid content (TFC) were evaluated using standard spectrophotometric methods; the antioxidant activity was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging, ferric-reducing antioxidant power (FRAP) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays; antimicrobial screening was performed against twenty test microorganisms; the ultraviolet (UV) protection effect of extracts and cosmetic emulsion was assessed spectrophotometrically in the wavelength range of 290–320 nm. HPLC analysis revealed fourteen phenolic compounds, including four phenolic acids (ellagic, gallic, p-coumaric, and ferulic), two tannins (pedunculagin and punicalagin), six flavonoids (myricetin, hesperidin, quercetin, luteolin, kaempferol, and apigenin), and two quercetin glycosides (rutin and hyperoside). The four pomegranate peel extracts demonstrated high TPC, TFC and antioxidant potential (DMSO > 70% ethanolic > methanolic > aqueous), and significant antimicrobial activity. The four extracts showed a remarkable UV protection effect. When applied in a cosmetic emulsion, the ethanolic extract showed sun protection factor (SPF) values from 13.59 (0.5 mg/g) to 50.65 (5 mg/g). Based on the results obtained, we can conclude that pomegranate peel is a promising source of bioactive compounds, which can be successfully utilized by integration into various pharmaceutical and value-added skin health products. Full article

In the present study, the changes in the groundwater quality in a Hungarian settlement, Báránd, were examined, nine years after the construction of a sewerage network. The sewerage network in the study area was completed in 2014, with a household connection rate exceeding 97% in 2023. In the summer of 2023, water samples were taken from 37 dug groundwater wells. Changes in the water quality were assessed using three water quality indicators (the Water Quality Index (WQI), Contamination degree (Cd), and Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI)) and geographic information (GIS), data visualization systems, and artificial intelligence (AI). During the evaluation of the quality of the groundwater, eight water chemical parameters were used (pH, EC, NH₄⁺, NO₂⁻, NO₃⁻, PO₄³⁻, COD, Na⁺). Based on interpolated maps and water quality indices, it was established that while an increasing portion of the area exhibits adequate or good water quality compared to the pre-sewerage period, a deterioration has occurred relative to recent years. Even nine years after the sewerage network construction, elevated concentrations of inorganic nitrogen forms and organic matter persist, indicating the continued presence of accumulated pollutants, as confirmed by all three water quality indicators to varying degrees and spatial patterns. The interactive data visualization and cloud-based sharing of the data of the water quality geodatabase were made freely available with the help of Tableau Public. A Feed-Forward Neural Network (FFNN) was developed to predict the groundwater quality, estimating the water quality statuses of three water quality indicators based on water chemistry parameters. The results showed that the applied training algorithms and activation functions proved to be the most effective in the case of different network structures. The most accurate prediction of the WQI and CCME WQI indicators was provided by the Bayesian control algorithm (trainbr), which achieved the lowest mean-squared error (RMSE_WQI = 0.1205, RMSE_{CCME WQI} = 0.1305) and the highest determination coefficient (R²_WQI = 0.9916, R²_{CCME WQI} = 0.9838). For the Cd index, the accuracy of the model was lower (RMSE = 0.1621, R² = 0.9714), suggesting that this indicator is more difficult to predict. With regard to our study, it should be emphasized that data visualization is a particularly practical tool for the post-processing of spatial monitoring data, as it is suitable for displaying information in an intuitive, visual form, for discovering spatial patterns and relationships, and for performing real-time analyses. AI is expected to further increase visualization efficiency in the future, enabling the rapid processing of large amounts of data and spatial databases, as well as the identification of complex patterns. Full article

Photoelectrochemical (PEC) sensors have garnered increasing attention due to their high sensitivity, low background signal, and rapid response. The incorporation of hydrogels into PEC platforms has significantly expanded their analytical capabilities by introducing features such as biocompatibility, tunable porosity, antifouling behavior, and mechanical flexibility. This review systematically categorizes hydrogel materials into four main types—nucleic acid-based, synthetic polymer, natural polymer, and carbon-based—and summarizes their functional roles in PEC sensors, including structural support, responsive amplification, antifouling interface construction, flexible electrolyte integration, and visual signal output. Representative applications are highlighted, ranging from the detection of ions, small biomolecules, and biomacromolecules to environmental pollutants, photodetectors, and flexible bioelectronic devices. Finally, key challenges—such as improving fabrication scalability, enhancing operational stability, integrating emerging photoactive materials, and advancing bio-inspired system design—are discussed to guide the future development of hydrogel-enhanced PEC sensing technologies. Full article