Natural gas sweetening, involving removal of CO2 and H2S from CH4, is conventionally carried out by amine scrubbing, which is highly energy intensive. In the present study, we report the synthesis of poly(vinyl alcohol-co-acrylic acid) (PVA-co-AAc) based nanocomposite membranes incorporated with surface-stabilized magnesium nanoparticles (MgNPs) through a simple aqueous route. The MgNPs act as Lewis basic sites providing reversible chemisorption for CO2/H2S, while the polymer matrix ensures hydrophilic pathways for solution–diffusion along with mechanical robustness. The prepared membranes were characterized by FTIR, XRD, SEM, TEM, AFM, TGA/DSC, DMA and tensile strength. Gas permeation studies at 25–60 °C and 1–10 bar revealed improved CO2/CH4 and H2S/CH4 selectivity, with CO2/CH4 selectivity reaching 20.8, without loss in permeance. The synergistic effect of polymer–nanoparticle interaction enhanced both stability and separation performance. Process analysis indicates potential energy savings compared to conventional amine processes, showing promise for industrial scale natural gas sweetening.
A series of novel 2-(1-(4-(4-chlorophenyl)thiazol-2-yl)-1H-pyrazol-4-yl)benzo[d]oxazoles 5 were synthesized from 2-[(E)-{1-[4-(4-chlorophenyl)-1,3-thiazol-2-yl]-1H-pyrazol-4-yl}(hydroxyimino)methyl]phenol 4 through Beckmann rearrangement. All the synthesized compounds were characterized with the help of IR, 1H and 13C NMR and LCMS techniques. All the synthesized compounds were screened for their in vitro anti-inflammatory and antioxidant activities. Among the newly synthesized compounds, compound 5c and 5e showed good anti-inflammatory activity and compounds 5c and 5d showed good antioxidant activity. Molecular docking study could provide valuable insights into the mechanism of anti-inflammatory activity. Furthermore, molecular docking studies into the active site of COX-2 enzyme indicated that compound 5c binds with good affinity, which is consistent with its considerable efficacy in the in vitro tests.
The present study investigated chemical composition and in vitro bioactivities of the essential oil (EO) of Macaranga trichocarpa leaves. The EO was analyzed using gas chromatography–mass spectrometry. The results showed the identification of 61 volatile constituents representing 97.54% of the total oil content. Sesquiterpene hydrocarbons were the predominant class (52.58%), with (E)-β-caryophyllene (17.66%), α-curcumene (16.04%), β-pinene (13.83%), linalool (9.52%), and β-caryophyllene epoxide (5.19%), identified as the major constituents. The EO showed weak antioxidant activity in both DPPH and ABTS radical scavenging assays. The EO demonstrated potent α-amylase inhibitory activity (IC50 = 120.70 ± 0.47 µg/mL), comparable to acarbose. Cytotoxicity evaluation using the MTT assay revealed that the EO exerted a dose-dependent inhibitory effect against the human hepatocellular carcinoma (HepG2) cell line. These findings provide the first report on the chemical composition of M. trichocarpa leaf EO, along with preliminary in vitro screening of its enzymatic and cytotoxic properties.
This study provides a comprehensive assessment of Ozoroa insignis Delile leaves in terms of their phytochemical, biological, and computational features. The extract showed substantial amounts of alkaloids (57.59 mg/g), flavonoids (141.48 mg/g), saponins (61.72 mg/g), and phenols (142.15 mg/g). DPPH and H2O2 scavenging activities reached 64.53% and 70.56%, respectively, at a concentration of 50 µg/mL. Fraction A showed the strongest inhibition, with the IC50 values of α-amylase and α-glucosidase of 53.61 and 78.5 µg/mL, respectively. Molecular docking showed that all six GC-MS-identified compounds exhibited binding affinities ranging from –4.6 to –6.0 kcal/mol. Overall, O. insignis is considered a promising source of bioactive compounds with antioxidant and enzyme-inhibiting properties for future pharmacological investigation.
A simple, precise UV-spectroscopy method using isosbestic point detection was developed for simultaneous analysis. The developed method exhibited good linearity over the concentration range of 0–12 μg/mL at both 269.7 nm and 252 nm. At 269.7 nm, the R2 values were 0.9963 and 0.9964 for ascorbic acid and resveratrol, with LOD/LOQ values of 1.597/4.838 μg/mL and 1.563/4.737 μg/mL, respectively. At 252 nm, the corresponding R2 values were 0.9922 and 0.9995, while the LOD/LOQ values were 2.537/7.688 μg/mL for ascorbic acid and 0.584/1.771 μg/mL for resveratrol. Percentage recovery rates of 50%, 100%, and 150% ranged from 98.6% to 100.6%, 98.5% to 100.4%, and 100.1% to 99.9%, respectively, with low %RSD values. %RSD of ascorbic acid and resveratrol combination, obtained during intra-day analysis, was 0.866% at λ1 and 0.486% at λ2. Inter-day test revealed a %RSD of 0.976% at λ1 and 0.664% at λ2, while repeatability was measured at 0.879 for λ1 and 0.411 for λ2, respectively. The developed UV method was simple, precise, and accurate for quantifying ascorbic acid and resveratrol in pure drugs in methanolic solution.
Aroylhydrazones have attracted considerable attention owing to their diverse biological properties and strong coordination ability toward metal ions. In the present study, two novel copper(II) complexes, [CuL(MeOH)]NO3·MeOH (1) and [CuBrL(MeOH)]·MeOH (2), derived from the aroylhydrazone ligand N’-(3-bromo-5-chloro-2-hydroxybenzylidene)-4-methylbenzohydrazide (HL), were successfully synthesized and comprehensively characterized using various physicochemical techniques. Single-crystal X-ray diffraction analyses revealed that the ligand coordinates to the copper(II) center in its deprotonated form (L⁻). Complex 1 exhibits a square planar geometry, and complex 2 exhibits a distorted square-pyramidal geometry around the Cu(II) ions. In complex 1, the coordination polyhedron is formed by the three donor atoms of the aroylhydrazone ligand and one methanol oxygen. In complex 2, the basal plane is defined by the three donor atoms of the aroylhydrazone ligand and one methanol oxygen, and the axial position is occupied by a bromide ligand. In addition, one methanol molecule is present as a solvent of crystallization in each complex. The supramolecular architectures of the complexes are further reinforced through intermolecular hydrogen-bonding interactions. Biological evaluation demonstrated that both copper(II) complexes possess remarkable inhibitory activity against Jack bean urease, with IC50 values of 0.5 and 1.1 μmol L⁻1 for complexes 1 and 2, respectively, indicating their potential as potent urease inhibitors.
Two cobalt(II) coordination compounds with 3-hydroxypyridine, [Co(3-pyOH)4(NCS)2] (1) and [Co(3-pyOH)2(μ-3-pyO)2]n (2), were synthesised from aqueous solution and characterised by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, and magnetic susceptibility measurements. Compound 1 is a discrete centrosymmetric complex in which the Co(II) ion adopts a slightly distorted octahedral N6 coordination environment formed by four neutral 3-pyOH ligands and two terminal N-bonded thiocyanate ligands. Compound 2 is a two-dimensional coordination polymer containing both neutral 3-pyOH and deprotonated μ-3-pyO- ligands, with the Co(II) ion in a distorted octahedral N2O4 donor environment. The crystal packing of both compounds is supported by hydrogen-bonding interactions and π–π stacking between pyridine rings. Hirshfeld surface analysis was used to evaluate the main close contacts contributing to the crystal packing. Infrared spectroscopy supports the structural assignments, particularly the presence of terminal N-bonded thiocyanate ligands in 1, while magnetic measurements indicate high-spin octahedral Co(II) centres in both compounds. The structures are compared with isostructural Ni(II), Mn(II) and Cd(II) coordination compounds.
This study reports the green synthesis of pristine, single-doped, and Fe/Co co-doped CuO nanoparticles using Bryophyllum calycinum extract. Doping was applied as a strategy to modulate the physicochemical and biological properties of CuO NPs. The NPs were characterized by EDX, XRD, FTIR, SEM, and UV–Vis spectroscopy, confirming crystallinity with a monoclinic phase and dopant-induced changes in band gap and lattice vibrations. SEM showed rough, irregular morphology. Biological assays revealed that Fe/Co co-doped CuO NPs exhibited superior antimicrobial activity 33 mm against S. enterica, 35 mm against A. niger, enhanced antioxidant efficiency, and minimal cytotoxicity at lower concentrations 0.3 mg/mL, 9% haemolysis. These findings demonstrate that Fe/Co co-doped CuO NPs synthesized via this eco-friendly approach possess promising bio-medicinal potential.
Neurosteroids modulate the function of γ-aminobutyric acid type A (GABAA) receptors in the brain. We showed that GABAA receptors modulate neurosteroid interactions with VDAC. GABA enhanced [3H]6-AziP labeling of VDAC in a concentration-dependent manner. This effect of GABA was prevented by the GABAA receptor antagonists gabazine and picrotoxin. Studies with brain tissue from mice deficient for VDAC showed that GABA enhanced [3H]6-AziP labeling of VDAC2 and VDAC1. GABA enhanced photolabeling of VDAC in HEK cells expressing γ2L-subunit, suggesting that the γ2L-subunit is required for the interaction of GABAA receptors with VDAC. VDAC1 and VDAC2 both co-immunoprecipitated with GABAA receptors in rat brain membranes. Collectively, the data provide evidence for a direct signaling pathway between the synaptic plasma membrane GABAA receptor and VDAC, a mitochondrial outer membrane protein.
A new series of 1,3,4-thiadiazole-2,5-dithiol-based acetohydrazide derivatives 6a–f has been designed and synthesized via a multi-step procedure that includes esterification and condensation reactions. Target compounds 6a–f were synthesized using various substituted aryl aldehydes and hydrazide intermediate 3. FT-IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis were used to characterize the synthesized compounds. The cytotoxic activity of the target compounds 6a-f against Caco-2 colorectal cells was evaluated at different concentrations using the MTT assay. The results showed that derivative 6a, which has a p-NO2 group on the phenyl ring, displayed good activity with an IC50 of 262.5 µg/mL. Molecular docking studies of compound 6a revealed a remarkable binding affinity towards HDAC1 and FGFR, with docking scores of –7.7 and –9.3 kcal/mol, respectively, facilitated by several hydrogen bonds and hydrophobic interactions. The DFT analysis revealed a high energy gap (9.882 eV), indicating good electronic stability, moderate electrophilicity, and significant molecular polarity, suggesting a favorable interaction potential in biological settings. Additionally, the drug-likeness and ADMET properties of the lead compound were predicted to be favorable based on in silico drug-likeness and ADMET evaluations.
Thiosemicarbazones have broad biological activities and play important role in coordination chemistry. In this work, three new copper(II) complexes, [Cu2LCl(µ-Cl)(EtOH)2]Cl (1), [CuL(OH2)]NO3·H2O (2), and [CuL(EtOH)]NO3·EtOH (3), where L is the deprotonated form of 2-hydroxy-3-methoxybenzaldehyde thiosemicarbazone (HL), were prepared and characterized by physico-chemical methods. Crystal structures of the complexes are further confirmed by single crystal X-ray determination. Complex 1 has a dinuclear copper(II) structure, and complexes 2 and 3 have mononuclear copper(II) structures. Inhibitory effect of the complexes on Jack bean urease was assayed. The complexes have remarkable activity with IC50 values of 0.3–1.1 μmol L–1.
A mechanistic explanation is central to scientific inquiry; however, learners often struggle to link macroscopic observations with submicroscopic interactions. This study investigated the mechanistic reasoning of 218 preservice science teachers (PSTs), enrolled in the second, third, or fourth year at a public university in eastern Türkiye, regarding boiling point elevation. Data were collected in a 60-minute session using a hypothetical scenario-based open-ended form requiring written explanations and visual representations, including drawings, particulate depictions, and causal arrows. Responses were analyzed through qualitative content analysis. The framework included explanatory components and reasoning levels. Most PSTs identified the target phenomenon, entities, and static properties, but struggled with submicroscopic activities, causal sequencing, and organization. Their reasoning remained mainly relational or simple causal, suggesting the need for tasks that foster multilevel mechanistic explanations.
Monocyclic β-lactams are valuable scaffolds for the development of novel antibacterial agents, and synthetic flexibility at the C3 position of the β-lactam ring is of particular interest. In this study, we evaluated multiple procedures for the deprotection of the tert‑butyldimethylsilyl (TBDMS) group in model azetidinone derivatives to enable early-stage functionalization of the C3 hydroxyl group. Given the sensitivity of the strained β-lactam ring and the presence of additional labile functionalities, careful selection of reaction conditions was required. Two optimized deprotection protocols were identified that successfully afforded the corresponding free alcohols, even in the presence of an acid- and base-sensitive dithiocarbamate moiety. In contrast, several literature-reported procedures proved ineffective under the tested conditions. Although the isolated yields were modest, the results demonstrate the feasibility of selective TBDMS removal in structurally complex monocyclic β-lactam systems. These findings establish a foundation for further optimization and provide a basis for expanding C3 functionalization strategies in the synthesis of novel β-lactam derivatives.
Thymol (TM), a monoterpenoid phenol with diverse antioxidant and antimicrobial properties, is of significant interest to the pharmaceutical, food, and agricultural sectors. Due to its importance, this study developed an electrochemical method for its quantification using a 3D-printed electrode made from a conductive carbon black/PLA filament (CB/PLA electrode). Electrochemical measurements were performed using square-wave voltammetry (SWV) in 0.1 mol L⁻1 Na2SO4 (pH 13). The potential was scanned from 0 to +0.80 V, exploiting the oxidation process of TM at approximately +0.30 V (vs. Ag|AgCl|KCl(sat.)). Under the optimized SWV conditions, a linear response was obtained in the concentration range of 75.00 to 337.50 µg/mL (r = 0.99). The proposed method demonstrated excellent analytical characteristics, including high stability (RSD < 9%; n = 6) and a satisfactory recovery value (89%). These results suggest minimal matrix interference, confirming the method's accuracy for analyzing real samples. This work highlights that the combination of 3D-printed electrodes and the SWV technique offers a selective approach for TM analysis. The reliability of the proposed method for quality control in thyme essential oil is confirmed, presenting a promising strategy for monitoring other bioactive compounds with a rapidly manufactured, reproducible, and low-cost electrode.
The two symmetric Schiff bases, 3,3′-((1E,1′E)-((4-methyl-1,3-phenylene)bis(azanylylidene)) bis(ethan-1-ylidene))bis(2-hydroxy-6-methyl-4H-pyran-4-one) (DL) and (N1E,N3E)-4-methyl-N1,N3-bis(pyridin-3-ylmethylene)benzene-1,3-diamine (PL), were synthesized and characterized using UV-Vis, FT-IR, 1H NMR, 13C NMR and LC-MS techniques. The infrared and UV-Vis spectral modelling using DFT for DL and PL showed good agreement between theory and experiment. The results of the antibacterial activity tests indicate that PL was more active against all bacterial strains than DL, which exhibited moderate antibacterial activity. Moreover, both compounds DL and PL exhibited significant antifungal potency against Botrytis species. Additionally, in silico ADME-T studies suggest that these compounds may have favourable oral bioavailability and pharmacokinetic properties. In addition, molecular docking studies were conducted to evaluate how these compounds interact with the active-site residues of TEM-1 β-lactamase, an enzyme responsible for the hydrolysis of β-lactam antibiotics. The docking results suggest that the synthesized DL and PL Schiff bases may serve as preliminary scaffolds for the development of new antimicrobial agents.
A promising strategy for preventing epileptogenic processes involves the development of modified aza-Michael adducts, which demonstrate a range of biological activities, including antioxidant, anti-inflammatory, and antiviral effects. In the present study, compound 3, administered at a dose of 50 mg/kg, prevented pentylenetetrazole-induced clonic seizures in 60% of mice (ED50 = 37.5 mg/kg), while compound 4 achieved seizure prevention in 40% of mice. With an ED50 value of 155.5 mg/kg, compound 3 was approximately four times more potent than ethosuximide. Importantly, neither the tested compounds nor ethosuximide (50–500 mg/kg) produced muscle relaxation or impaired motor coordination. Furthermore, derivatives of compound 3 exhibited not only anticonvulsant activity but also anxiolytic and antidepressant effects, surpassing ethosuximide in the conducted assays. Ongoing research aims to further explore and optimize this series of compounds for potential therapeutic use.
A new hydrazone compound 3-hydroxy-N’-(2-hydroxy-4-methoxybenzylidene)benzohydrazide (HL) and its isostructural cobalt(II) and nickel(II) complexes [M2Cl2L2(EtOH)2] (M = Co for 1, Ni for 2) were synthesized and characterized by physico-chemical methods such as elemental analysis, infrared and electronic spectroscopy. The free hydrazone HL was also characterized by 1H and 13C NMR spectroscopy. Structures of HL and the two complexes were further confirmed by single crystal X-ray determination. The hydrazone ligand in the complexes coordinates to the metal atoms through phenolate oxygen, imino nitrogen and carbonyl oxygen atoms. The metal atoms in the complexes are in octahedral coordination. The hydrazone and both complexes were assayed for antibacterial activities on the bacterial strains Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and on the fungal strains Candida albicans and Aspergillus niger, and gave interesting results.
This study evaluates the photodynamic inactivation potential of a coumarin-functionalized zinc(II) phthalocyanine derivative against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591. The antimicrobial and cytotoxic effects of the derivative were assessed under dark and laser-irradiated (658 nm) conditions. Minimum inhibitory concentration (MIC) values were determined, and the photodynamic response was further explored in MRSA-infected HT-29 (human colorectal adenocarcinoma) and HUVEC (human umbilical vein endothelial) cell models. While the derivative exhibited dose-dependent antibacterial activity, the light-induced reduction in colony-forming units (CFU) was moderate, remaining below a tenfold (1-log10) under the tested conditions. In cell-based assays, the compound showed detectable dark cytotoxicity, which was further enhanced upon laser irradiation. The photodynamic cytotoxic response was more pronounced in infected HT-29 cells than in infected HUVEC cells, with flow-cytometric profiles consistent with predominantly necrotic/late apoptotic cell-death patterns. These findings indicate that the compound exhibits light-enhanced effects in complex infection models; however, further optimization of formulation, photophysical properties, and light dosimetry is required to improve antimicrobial efficacy and selectivity.
This study investigates a series of zingerone 2-thiohydantoins for anticancer activity towards human breast adenocarcinoma and explores possible mechanisms of anticancer action. Cytotoxicity was tested on highly invasive triple negative breast cancer MDA-MB-231 cells and healthy MRC-5 cells. The most active compound 2e exerted a significant cytotoxic effect on breast cancer cells, while exhibiting no measurable toxicity on healthy cells. Fluorescence measurements of interactions with human serum albumin, combined with molecular docking, showed strong binding and transport capabilities, suggesting good bioavailability. Fluorescence and hydrodynamic measurements with DNA displayed lower binding affinity, suggesting that protein targets are responsible for anticancer action. Thorough molecular docking screening on 36 possible breast adenocarcinoma protein targets was performed and results suggest competitive inhibition of DNA methyltrasferase 1 as the mechanism of anticancer action. ADMET analysis predicted favorable physicochemical and pharmacokinetic properties.
