The present study aimed to synthesize and characterize biogenic silver nanoparticles (AgNPs) using an aqueous leaf extract of Leucas aspera and evaluate their antibacterial and anticancer activities. Phytochemical screening revealed flavonoids, phenols, alkaloids, tannins, saponins, carbohydrates, glycolysis-related compounds and steroids. GC-MS analysis identified 25 phytoconstituents, including lupeol, β-sitosterol, γ-linolenic acid, palmitic acid, stearic acid and retinyl palmitate, which may contribute to AgNPs formation and biological activity. UV-Visible spectroscopy confirmed AgNPs formation through a characteristic SPR band at 415 nm, while XRD revealed a face-centered cubic crystalline structure with an average crystallite size of 86.08 nm. FTIR analysis indicated the involvement of phenolic and flavonoid functional groups in Ag+ reduction and nanoparticle stabilization. SEM, EDX, DLS and zeta potential analyses revealed near-spherical nanoparticles with an average particle size of 65.82 nm, hydrodynamic diameter of 118.74 nm, negative surface charge of -26.78 mV and 64.27 wt.% Ag composition. The synthesized AgNPs exhibited concentration-dependent antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, with MIC and MBC values of 100 and 125 µg/mL, respectively. Furthermore, AgNPs showed enhanced cytotoxicity against HEp-2 laryngeal carcinoma cells with an IC50 value of 236.63 µg/mL.
Bis-indole derivatives represent an important class of indole-based compounds with substantial structural diversity and broad pharmacological potential. The presence of two indole units, connected through direct bonds or diverse linkers, provides opportunities to modulate molecular conformation, target interactions and biological activity through systematic structural modification. This review provides a critical overview of recent advances in bis-indole chemistry, with emphasis on synthetic methodologies, biological activities, structure-activity relationships and emerging therapeutic applications. Conventional synthetic approaches, such as acid-catalyzed condensation, oxidative coupling and stepwise functionalization, are discussed together with more recent developments in transition-metal catalysis, multicomponent reactions, microwave-assisted synthesis, photoredox and electrochemical transformations and sustainable catalytic systems. These approaches have expanded the accessible structural diversity of bis-indoles and improved reaction efficiency, selectivity and, in several cases, sustainability. Biologically, bis-indole derivatives have been investigated across diverse therapeutic areas, including cancer, infectious diseases, inflammation, neurological and metabolic disorders. Reported mechanisms include modulation of protein kinases, topoisomerases, microtubule dynamics, inflammatory signalling, oxidative stress and drug-efflux pathways, although the strength of mechanistic evidence varies among individual compounds. Beyond conventional pharmacological applications, bis-indole frameworks have also been explored in photodynamic therapy, molecular imaging, drug-resistance modulation and drug-delivery systems. Despite extensive research, most bis-indole candidates remain at the preclinical or experimental stage. Poor aqueous solubility, limited bioavailability, metabolic instability, off-target interactions and potential toxicity remain significant barriers to clinical development. In addition, regioselective and stereoselective synthesis, scalability and reproducibility require further improvement. Future progress will depend on establishing clearer relationships among molecular structure, target engagement, biological activity, pharmacokinetic behaviour and toxicity. Integration of sustainable synthesis, medicinal chemistry, structural biology, computational modelling and data-driven approaches, supported by standardized biological evaluation, may facilitate the identification of better-characterized candidates. Such efforts could help translate the broad chemical and biological potential of bis-indoles into therapeutically relevant applications.
Titanium dioxide (TiO2) is a widely studied photocatalyst, although its broad band gap restricts its response mainly to the ultraviolet region. This study investigates the effect of cobalt doping on the optical properties and photocatalytic activity of TiO2 under ultraviolet (UV), visible and solar irradiation. Co-doped TiO2 containing 0.5 mol% Co was synthesized by the sol–gel method. The crystal structure, morphology, particle size and elemental composition were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDX). Optical absorption characteristics were evaluated by UV-visible diffuse reflectance spectroscopy (DRS) and the band gap energy was estimated from Tauc plots. The photocatalytic activity of the materials was evaluated using Alizarin dye as a model pollutant under UV, visible and solar irradiation, with the degradation kinetics analyzed using a pseudo-first-order model. XRD analysis confirmed the formation of highly crystalline, single-phase anatase TiO2. TEM images revealed nearly spherical nanoparticles with particle sizes of approximately 30-40 nm, while SAED patterns were consistent with the crystalline anatase structure. EDX analysis confirmed the presence of Co and TiO2 constituents without detectable extraneous elements. Co doping reduced the optical band gap from 3.2 eV for pristine TiO2 to 2.0 eV for Co-doped TiO2, extending the light absorption toward the visible region. After 60 min of irradiation, Alizarin red S (ARS) degradation reached 73.53%, 48.44% and 63.46% under UV, visible and solar light, respectively, with corresponding pseudo-first-order rate constants of 0.01819, 0.01073 and 0.01608 min–1. The reduced band gap and enhanced reaction kinetics under visible and solar irradiation establish Co-doped TiO2 as an effective photocatalyst for light-assisted wastewater treatment.
The present study evaluates the stability of netupitant under various environmental stress conditions and identifies the degradation products formed during the degradation process. In addition, the study predicts the pharmacokinetic and toxicological properties of these degradation products using advanced analytical and computational approaches. Isocratic liquid chromatography was used to separate stress samples, high-resolution quadrupole time-of-flight mass spectrometry was used to elucidate the structure of these samples. Computational platforms were used in making predictions of toxicity and molecular docking simulations were performed to assess the relative binding affinities of the parent drug and its degradants to the human neurokinin-1 receptor. Netupitant was susceptible to oxidative and hydrolytic stress, mainly through oxidative cleavage of the piperazine ring. Molecular docking showed that netupitant has the best neurokinin-1 receptor binding affinity (-12.1 kcal/mol) and structural loss in the degradants slightly alters the binding affinity towards the receptor (between -11.3 and -10.2 kcal/mol). Shifting the degradation products through software screens comprising the pkCSM webserver, ToxTree and OSIRIS property explorer yielded predictions for various pharmacokinetic and toxicity-related parameters. The computational predictions highlighted high intestinal absorption and hepatotoxicity across all compounds, with specific mutagenic structural alerts identified in one degradation product and a tumorigenic alert in another.
A series of ten 1,2,4-triazole-3-yl-sulfanyl-acetamide derivatives bearing a mercapto (-SH) group were synthesized and characterized using FTIR, 1H NMR, 13C NMR, UV, mass spectrometry and DSC. The compounds were prepared within two structural frameworks: (i) N-(p-toluoyl)-{[4-phenyl-5-(pyridin-4-yl)-4H-1,2,4-triazol-3-yl]sulfanyl}acetamide and (ii) N-[4-(1-oxo-3-phenyl-propenyl)phenyl]-2-(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-ylsulfanyl)acetamide. Molecular docking against COX-2 (PDB ID: 5F1A) highlighted compound 4a from framework I (binding energy -12.09 kcal mol–1) and compound 5e from framework II (binding energy -13.15 kcal mol–1) as the most promising compounds with favourable interactions, supporting their potential as lead molecules for further biological evaluation. In addition, physico-chemical, pharmacokinetic and HOMO-LUMO (ΔEH-L = 9.985 and 9.986 eV) also suggested that 4a and 5e are two lead candidates with positive drug-ability profiles (0.60 and 0.68). Prior to selecting safe/non-toxic doses of both leads for biological activity, the acute oral toxicity was investigated following the OECD-423 guidelines, where 200 and 400 mg/kg were selected as non-toxic doses for in vivo biological activity. The analgesic activity of the lead compounds 4a and 5e was evaluated in Wistar albino rats using the Eddy’s hot plate method. Anti-inflammatory effects were investigated through both in vitro protein denaturation assays (employing hot and cold-water extracts) and the in vivo carrageenan-induced paw edema model. The antioxidant potential of 4a and 5e was evaluated using the DPPH radical scavenging assay. Structural variation from the simple aryl scaffold of 4a to the chalcone framework of 5e provided insight into the structure–activity relationship. The ortho-hydroxy substituent in 5e enhanced radical-scavenging capacity and may contribute to its activity against oxidative stress, pain and inflammation. In silico, in vitro and in vivo findings identified 4a and 5e as promising derivatives with favourable analgesic, anti-inflammatory, antioxidant and drug-likeness profiles.
In the present study, we report the green synthesis of Barleria acuminata extract mediated copper phosphate nanohybrids (BAE-CuPNHs) by a simple one-pot co-precipitation approach. Aqueous extracts of six different Barleria species were prepared by using ultrasonication and microwave-assisted extraction methods and evaluated for total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity. Among the tested species, B. acuminata showed highest phytochemical content and DPPH radical scavenging activity and was selected for nanohybrid preparation. The formation of nanohybrid was screened for different metal ions. Copper ions formed well-defined flower-like nanostructures with high efficiency of phytochemical immobilization. Optimization studies showed 4 mM CuSO4, 2.0 mL PBS, static incubation and an incubation period of 72 h as the optimum conditions for the synthesis. FESEM, EDX, FTIR and XRD characterization confirmed the formation of crystalline BAE-CuPNHs with marigold-like morphology. The synthesized BAE-CuPNHs displayed antioxidant activity, indicating their promising prospects for antioxidant delivery and bioactive applications.
A detailed investigation of charge transport, encompassing direct-current (DC) and alternating-current (AC) conduction, was performed for samarium-doped manganite nanoparticles and their polypyrrole (PPy)-based nanocomposites. The electrical transport characteristics of the pristine manganite and nanocomposite systems were examined as a function of temperature, magnetic field and samarium concentration. The pristine manganite exhibits characteristic polycrystalline magnetoresistance (MR), with MR increasing from ~55% for the lowest samarium concentration (M1) to ~75% for the highest concentration (M5) at 50 K. Spin-polarized tunneling across grain boundaries constitutes the dominant MR mechanism, with the temperature dependence supporting the role of suppressed spin fluctuations. The nanocomposites exhibit anomalous, fluctuation-like field-dependent MR behaviour that varies with temperature and samarium concentration, with the effect being most pronounced at lower samarium concentrations over the 50-250 K temperature range. This behaviour is attributed to the competition between weak localization and charge-carrier delocalization within a core-shell architecture, mediated by intermediate exchange coupling and the incorporation of polypyrrole. The distinct transport and magnetoresistance responses of the manganite nanoparticles and PPy-based nanocomposites provide insight into the interplay between grain-boundary effects, magnetic exchange interactions and polymer-mediated charge transport.
A novel racemization process was developed for the conversion of (S)-tolterodine, obtained as a byproduct during the resolution of racemic tolterodine, into racemic (R,S)-tolterodine. The process involves protection of the phenolic hydroxyl group with benzyl chloride, followed by racemization using potassium tert-butoxide in DMSO at 60-65 ºC. Subsequent debenzylation with Raney nickel afforded racemic tolterodine, which was resolved with L-(+)-tartaric acid to obtain tolterodine tartrate. The racemization of the undesired (S)-enantiomer enables its recycling into the resolution process, thereby reducing material loss and providing a practical approach for improving the yield of the desired (R)-tolterodine.
The homoleptic ruthenium(II) complex [Ru(bbp)2]2+ (bbp = 2,6-bis(benzimidazol-2-yl)pyridine) has been synthesized and characterized by elemental analysis, UV-Visible, FTIR, 1H NMR, 13C NMR and MALDI-TOF-MS techniques. The spectroscopic data support coordination of the tridentate bbp ligand to the ruthenium center and formation of the proposed complex. Its electronic absorption profile features a characteristic metal-to-ligand charge-transfer (MLCT) transition arising from excitation of metal-centered orbitals to ligand-centered π*-orbitals. DFT calculations at the B3LYP/LANL2DZ level were used to examine the optimized molecular structure, frontier molecular orbitals and electronic properties, while TD-DFT calculations with an acetonitrile solvation model were employed to interpret the observed absorption features. The frontier orbital distribution places the occupied states mainly on the ruthenium center and the low-lying unoccupied states on the coordinated ligands, supporting the MLCT character of the complex. Conceptual DFT descriptors provide insight into its electronic stability, charge-transfer propensity and chemical reactivity. The combined experimental and computational study establishes a coherent relationship between the molecular structure, electronic configuration and optical response of the [Ru(bbp)2]2+ complex.
Dye-sensitized solar cells (DSSCs) are considered as third-generation photovoltaic technology due to single-device architecture, simple fabrication and good performance. Metal-free organic dyes having a donor-π-acceptor (D-π-A) architecture, have attracted major attention of researchers due to the facts that their electrochemical and optical properties can easily be tuned. In this work, two carbazole-based organic dyes, M1 and M2, were computationally designed and tested as potential DSSC sensitizers using density functional theory (DFT) and time-dependent DFT (TD-DFT) methodology. Ground-state geometry optimization at the B3LYP/6-31G(d,p) level which revealed that M1 possesses a more planar molecular structure compared to M2, thereby facilitating enhanced π-conjugation and intramolecular charge transfer. Frontier molecular orbital analysis in both gas and solvent phases revealed that M1 exhibits slightly greater electronic delocalization and excitability compared to M2. Simulated UV-Vis absorption spectra showed strong visible-light absorption, with M1 displaying a red-shifted maximum absorption wavelength (λmax) at 458.81 nm and good light-harvesting capability. Further studies of molecular electrostatic potential (MEP), natural bond orbital (NBO), density of states (DOS), partial density of states (PDOS), reorganization energy and photovoltaic parameters confirmed the favourable charge-transfer characteristics of M1 and M2. Although M2 has lower reorganization energy than M1, the other calculated properties favour M1, which exhibits more favourable optical and electronic characteristics and may be a promising candidate for further experimental evaluation.
α-Glucosidase is an intestinal membrane-bound enzyme that catalyzes the final step in the digestion of carbohydrates. It cleaves the glycosidic bonds of oligosaccharides to release glucose and its inhibition results in delayed glucose absorption, thereby inhibiting post-prandial hyperglycemia and hyperinsulinemia in patients with type 2 diabetes. Therefore, in view of the biological role of α-glucosidase as an antidiabetic drug target, a series of 5-(substituted)-1,3-thiazolidine-2,4-diones (C1-C6) were designed, synthesized and characterized by FT-IR, 1H NMR, 13C NMR and mass spectral analyses. All the compounds were subjected to in vitro α-glucosidase inhibitory evaluation. Among the compounds tested for α-glucosidase inhibitory activity, compounds C1 and C3 exhibited significant inhibition, with IC50 values of 0.1363 ± 0.00085 µM and 3.63780 ± 0.00005 µM, respectively. Structure-activity relationship (SAR) analysis of the test compounds revealed the positive contribution of the 1,3-thiazolidine-2,4-dione moiety and the phenyl ring substituents at the 5-position of the 1,3-thiazolidine-2,4-dione scaffold towards the observed activity.
Triazine–sulfonamide hybrids offer a versatile scaffold for antimicrobial drug, with the triazine core enabling structural modification and the sulfonamide group supporting target interactions. DHFR inhibition by these hybrids provides a rational strategy for developing new antimicrobial agents against the growing challenge of AMR. Hence, the present study focuses on the synthesis, structural characterization and evaluation of triazine–sulfonamide hybrids (A1–A12) for DHFR binding, supported by integrated in silico modelling and in vitro antimicrobial studies. Molecular docking with DHFR (PDB ID: 1RX3) showed good binding affinities (-8.5 to -10.2 kcal/mol), with key hydrogen-bonding interactions involving Asp27, Arg52, Arg57 and Ile94. Compounds A1 and A12 showed stronger binding than ciprofloxacin (-9.1 kcal/mol) and trimethoprim (-7.6 kcal/mol), which support its potential as DHFR-targeting antimicrobial candidates. In vitro antimicrobial screening via the tube dilution method demonstrated broad-spectrum potency across bacterial and fungal strains: compound A1 exhibited the lowest MIC against Escherichia coli (1.05 ± 0.06 µg/mL), compound A10 against Staphylococcus aureus (2.11 ± 0.08 µg/mL), compound A4 against Bacillus subtilis (2.14 ± 0.08 µg/mL) and Candida albicans (1.11 ± 0.05 µg/mL), compound A12 against Pseudomonas aeruginosa (1.19 ± 0.05 µg/mL) and compound A5 against Aspergillus niger (2.41 ± 0.09 µg/mL). Molecular dynamics (MD) simulations confirmed the dynamic stability and structural integrity of the top performing ligand DHFR complexes under simulated physiological conditions. DFT calculations provided insight into the frontier molecular orbitals and chemical reactivity descriptors, supporting the electronic stability and reactivity of the active scaffolds.
Nitrosamine impurities, particularly N-nitrosodimethylamine (NDMA), are potent genotoxic and carcinogenic compounds that can pose significant risks even at trace concentrations. Their occurrence in pharmaceutical products, including cardiovascular, antidiabetic and gastro-retentive drugs, has raised major regulatory concerns, leading to recalls and restrictions on affected products. This study presents an electrochemical sensor for the trace-level detection of NDMA using a polymer-modified glassy carbon electrode (GCE). Silver nanoparticles embedded in polycystamine were integrated onto the GCE surface to enhance the analytical response, sensitivity and selectivity toward NDMA. The electrochemical behavior and quantitative detection of NDMA were investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square-wave voltammetry (SWV). Surface morphology and modification of the electrode were examined by scanning electron microscopy (SEM). Interference studies were performed to assess the selectivity of the sensor in the presence of potentially coexisting species. The developed silver nanoparticle–polycystamine/GCE platform provides a sensitive and selective electrochemical approach for NDMA detection, with potential application in pharmaceutical quality control and analysis of complex industrial matrices.
Benzothiazole and isatin scaffolds possess considerable biological importance and their molecular hybridization may provide a promising approach for enhancing anticonvulsant activity. The present study focused on the design, synthesis and evaluation of a novel series of 6-substituted-N'-(5-substituted-2-oxoindolin-3-ylidene)benzo[d]thiazole-2-carbohydrazide derivatives (IBS01-IBS08) using computational and experimental approaches. Molecular docking studies were performed using AutoDock 1.5.6 against γ-aminobutyric acid (GABA) aminotransferase (PDB ID: 1OHV) to investigate the binding interactions of the synthesized derivatives. The compounds were synthesized and characterized by IR, NMR and mass spectrometry. Their anticonvulsant activity was evaluated in vivo using the maximum electroshock seizure (MES) model at doses of 30 and 100 mg/kg, with hind-limb tonic extension (HLTE) used as the primary endpoint. Phenytoin (25 mg/kg, i.p.) served as the reference standard. The rotarod test was employed to assess motor coordination deficits. The docking results shows the valuable binding interactions of the synthesized hybrids with GABA-aminotransferase. All derivatives markedly decreased the duration of MES-induced HLTE without causing death. Phenytoin demonstrated significant anticonvulsant efficacy (***p < 0.0001) throughout all convulsive phases. The Rotarod test revealed no significant neurotoxic effects at the tested active doses. The synthesized benzothiazole-isatin hybrids exhibited significant anticonvulsant activity, favourable in silico binding affinity and low neurotoxicity, supporting their potential as lead structures for further development of antiepileptic agents.
Wastewater generated by the textile industry contains substantial amounts of organic pollutants, particularly synthetic dyes, which pose serious risks to human health and aquatic ecosystems. The removal of these contaminants from water bodies is essential, necessitating the development of cost-effective and efficient treatment strategies. The present study focuses on the development of cost-effective nanostructured materials for dye removal from wastewater and antibacterial activity against both Gram-positive and Gram-negative bacteria. A NiFe2O4/rGO heterojunction was synthesized via a one-pot hydrothermal method and characterized to assess its structure, morphology and optical properties. The synthesized material was evaluated for its catalytic removal of methylene blue (MB) and malachite green (MG) dyes and NiFe2O4/rGO (10%) showed 98.01% and 98.53% removal of MB and MG dyes, respectively, in 120 min. The catalytic removal rate of NiFe2O4/rGO (10%) heterojunction was much faster (98.01%; 98.53%) than the pure NiFe2O4 (73.43%; 73.16%) under visible light illumination. The substantial stability and reusability of the heterojunction were assessed through repeated photocatalytic degradation cycles. Its antibacterial activity was evaluated against the selected multidrug-resistant microorganisms, with NiFe2O4/rGO exhibiting significant zones of inhibition against both bacterial strains. These findings support the potential application of NiFe2O4/rGO in wastewater treatment, particularly for the removal of organic dyes and bacterial contaminants.
This study focuses on the synthesis and evaluation of the antimicrobial, anti-inflammatory and antipyretic activities of novel thiazole-based Schiff base derivatives (S1-S6). The compounds were synthesized through condensation reactions between 2-aminothiazole and several aromatic aldehydes. Structural characterization of the synthesized derivatives was carried out using FTIR, 13C NMR, 1H NMR, mass spectrometry techniques and elemental analysis. Initially, thiazole-based Schiff base derivatives therapeutic activities were assessed from AutoDock score after the successful binding with Staphylococcus aureus DNA gyrase B and cyclooxygenase 2. The synthesized derivatives were also evaluated for antimicrobial, anti-inflammatory and antipyretic activities using in vitro and in vivo methods. Compounds S6 and S1 showed the highest activity, possibly due to the thiazole nucleus linked to furan and substituted aromatic rings. The experimental findings were consistent with the in silico molecular docking results.
The 4f-4f absorption spectra of Pr3+ were employed as sensitive probes to investigate the interaction of Pr3+ with L-leucine in the presence and absence of Mg2+ in various aquated organic solvents, namely DMF, acetonitrile (ACN), dioxane and methanol. The interaction of Pr3+ with L-leucine was evaluated through the determination of spectroscopic energy parameters, including the Slater-Condon parameters (Fk), spin-orbit coupling parameter (ξ4f), bonding parameter (b1/2), nephelauxetic ratio (β), percentage covalency (δ) and Racah parameter (Eᵏ). These parameters were used to assess changes in the electronic environment and the nature of metal–ligand interactions. Variations in the absorption intensity parameters, including the oscillator strengths (P) of the individual 4f-4f transitions and Judd-Ofelt intensity parameters (Tλ), provided further evidence for the coordination of L-leucine with Pr3+. Upon addition of L-leucine, the characteristic absorption bands of Pr3+ exhibited bathochromic shifts accompanied by hyperchromic effects, which confirmed the changes in the coordination environment and electronic structure of the metal ion. The influence of Mg2+ on the Pr3+–L-leucine interaction was further examined to elucidate its role in the complexation process. Kinetic and thermodynamic investigations were subsequently performed to determine the mechanism, stability and energetics of complex formation in the different solvent systems. The combined spectroscopic, kinetic and thermodynamic results provide insight into the nature of Pr3+–L-leucine interactions and the influence of Mg2+ and solvent environment on their complexation behaviour.
Eggshell waste, an inexpensive and abundant material, serves as an eco-friendly adsorbent for wastewater treatment. This study evaluates its efficiency in removing methylene blue (MB) dye and ofloxacin (OFX) antibiotic from aqueous solutions. The adsorbent was characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to assess its surface morphology and composition. Batch adsorption experiments identified the optimal conditions as 0.04 g of adsorbent, a contact time of 120 min, an initial MB concentration of 4 mg/L and an initial OFX concentration of 6 mg/L. Under these conditions, the removal efficiencies reached 73.01% for MB and 85.34% for OFX, with maximum adsorption capacities of 9.95 mg/g and 0.93 mg/g, respectively. Methylene blue (MB) dye adsorption was strongly affected by solution pH and electrostatic interactions, whereas OFX adsorption involved electrostatic attraction, hydrogen bonding and surface complexation. Kinetic studies revealed that MB adsorption followed a multi-step diffusion mechanism, while OFX adsorption was best described by the pseudo-second-order kinetic model. Thermodynamic analysis indicated that the adsorption of both pollutants was spontaneous and endothermic, accompanied by positive entropy changes. The adsorbent exhibited good regeneration performance, retaining more than 50% of its MB and OFX removal efficiencies after five adsorption-desorption cycles. These findings demonstrate that the eggshell waste calcined at 600 ºC is an efficient, reusable and sustainable adsorbent with considerable potential for the treatment of dye- and antibiotic contaminated wastewater.
ZnO nanoparticles have attracted considerable interest owing to their structural stability, wide band gap, high exciton binding energy and diverse functional characteristics. Their practical performance, particularly in photocatalytic applications, is constrained by rapid electron–hole recombination and limited absorption in the visible region. In the present study, the pristine ZnO (Z1), Cu-doped ZnO (Z2) and Co-doped ZnO (Z3) nanoparticles were synthesized through a controlled co-precipitation route. The prepared materials were characterized by X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence (PL), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), photocatalytic dye degradation and vibrating sample magnetometry (VSM). XRD analysis confirmed the retention of the hexagonal wurtzite ZnO phase after Cu and Co incorporation, accompanied by changes in crystallite characteristics and lattice parameters associated with dopant-induced strain and defect formation. SEM analysis indicated modifications in particle morphology, surface texture and aggregation behaviour upon metal-ion incorporation. The optical characteristics were strongly influenced by doping, with a shift in light absorption toward the visible region and a reduction in charge-carrier recombination, with the Co-doped sample (Z3) exhibiting the most pronounced response. The photocatalytic activity was influenced by the dopant-induced electronic states, which facilitated the separation of photogenerated electron–hole pairs and improved their participation in the photocatalytic process. VSM measurements further established changes in the magnetic response following transition-metal incorporation. The findings establish Cu and Co doping as effective approaches for tailoring the structural, optical, morphological and magnetic characteristics of ZnO nanoparticles, with Co incorporation providing a particularly notable modification of the investigated properties.
A series of new indole-pyrazole-linked isoxazole hybrids (5a-o) were synthesized using Cu(I)-catalyzed 1,3-dipolar cycloaddition and assessed for antibacterial and antibiofilm activities against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) pathogens. Biological evaluation showed that the dihalogenated derivatives, particularly 3,5-dichloro (5g) and 2,4-dichloro (5i), exhibited pronounced antibacterial activity comparable to dicloxacillin. Both compounds substantially inhibited biofilm formation. Molecular docking studies against penicillin-binding protein (PDB ID: 1MWT) supported the experimental findings, with favourable binding interactions and high predicted affinity. Structure-activity relationship analysis indicated that dichloro substitution enhanced antibacterial potency. These hybrid compounds may serve as potential candidates for further investigation against resistant Staphylococcus aureus infections.
