Abbottabad University of Science and Technology

This work introduces a low-cost and straightforward approach for fabricating metal nanoparticle-based catalysts using chitosan-coated cellulose tissue (CS-CTP) as a flexible support. Metal ions (Ni and Co) were adsorbed onto the biopolymer-coated squares and subsequently reduced to their metallic state via sodium borohydride treatment. Structural and functional characterization techniques, including Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), confirmed the successful nanoparticle deposition and interaction with the polymer matrix, highlighting the composite’s structural integrity and potential for catalysis. The as-prepared materials were efficient catalysts for hydrogen evolution. The influence of key operational variables, including metal content, NaBH4 concentration, temperature, and catalyst reusability, was thoroughly examined. Among the tested systems, Ni-loaded chitosan-coated cellulose tissue paper (Ni@CS-CTP) exhibited remarkable hydrogen production efficiency, achieving up to 420 mL of H2 within 30 min using 10 mg / 10 mL in methanol–NaBH4 solution. Additionally, the same catalyst was tested for environmental remediation by targeting Congo red dye, achieving complete reduction in only 7 min. Notably, the catalyst maintained high performance across five cycles, demonstrating its practical potential in green energy production and water treatment technologies.

Pyrazole-linked 1,3,4-oxadiazole hybrids 8-11 were synthesized and evaluated for in vitro alpha-amylase inhibition. Among all the newly synthesized scaffolds, compound 9 was found to exhibit the most potent inhibitory profile against alpha-amylase, with an IC50 = 3.10 +/- 0.80 mu M, comparable to the standard acarbose (IC50 = 1.48 +/- 0.30 mu M). The elevated inhibitory profile of the 9 scaffold might be due to the presence of an ortho-hydroxyl substitution on the oxadiazole ring, enhancing activity via probable hydrogen bonding. In contrast, the reduced activity of 10 was attributed to steric hindrance and the lack of hydrogen bond donors. Spectroscopic techniques such as 1H- and 13C-NMR spectroscopy were used to confirm the structures of all the newly developed scaffolds. Molecular docking results were consistent with the experimental IC50 values and support these findings, with 9 showing the highest binding affinity (-4.944 kcal/mol) compared to acarbose (-2.506 kcal/mol). ADMET predictions and drug-likeness evaluations indicated favorable pharmacokinetic properties, while DFT studies provided electronic insights correlating with bioactivity. These results highlight 9 as a promising alpha-amylase inhibitor scaffold.

A novel series of thiadiazole-based Schiff base derivatives (1-16) was synthesized via an efficient multi-step route and characterized using 1H NMR, 13C NMR, and HREI-MS. These compounds were evaluated for their anti-Alzheimer's and anti-urease potential. Among them, compounds 8 and 9 exhibited the most potent inhibition with IC₅₀ values of 6.60 ± 0.40 and 8.10 ± 0.10 μM for AChE, 7.40 ± 0.20 and 8.80 ± 0.40 μM for BChE, and 9.75 ± 1.60 and 10.15 ± 0.50 μM for urease, respectively. Donepezil and thiourea were used as standard inhibitors for comparative evaluation. Molecular docking and pharmacophore modeling supported the inhibitory potential of these compounds. ADMET profiling confirmed favorable drug-likeness and pharmacokinetic properties, while DFT and molecular dynamics simulations validated their stability and reactivity. These results highlight compounds 8 and 9 as promising leads for further development as multifunctional therapeutic agents against Alzheimer's disease and urease-related pathologies.

This research focuses on the design, synthesis and biological evaluation of imidazopyridine-based thiadiazole derivatives incorporating benzoxazole moieties. These compounds were investigated as dual inhibitors of acetylcholinesterase (AChE) and butyrylcholineesterase (BuChE), crucial for neurotransmission. Targeting these enzymes presents a viable strategy for controlling neurological conditions, particularly Alzheimer's disease (AD). A total of 18 derivatives (1- 18) were synthesized and structurally characterized using 1H NMR, C-13 NMR and HREI-MS techniques. The in vitro enzyme inhibition assays demonstrated significant activity, with IC50 values ranging from 1.10 +/- 0.70 mu M to 35.80 +/- 7.60 mu M for AChE and 2.40 +/- 0.90 mu M to 37.50 +/- 7.80 mu M for BuChE. In comparison, the reference drug Donepezil exhibited IC50 values of 10.30 +/- 1.10 mu M and 15.60 +/- 1.80 mu M for AChE and BuChE, respectively. Derivatives 14, 10, 4 and 9 showed the strongest inhibitory effects among the synthesized compounds. Furthermore, molecular docking studies were performed to elucidate the interaction of these derivatives with the active sites of AChE and BuChE. The computational findings aligned with the experimental data, confirming strong binding affinities and favorable interaction profiles. These findings underscore the therapeutic potential of these compounds as potential anti-AChE and BuChE agents, particularly in the context of Alzheimer's disease treatment.

Rare-earth doping offers a powerful route to transform chemically robust oxides into multifunctional materials with coupled electronic, optical, and magnetic responses. Here, we present comprehensive first-principles studies of pristine and Tm-doped Ca2SnO4, exploring how localized 4f states change structural, electronic, magnetic, and optical properties. Pristine Ca2SnO4 is confirmed as a mechanically stable, wide-bandgap insulator with predominantly ionic-covalent bonding and diamagnetic character. Upon substitution of Ca2+ by Tm3+, profound modifications emerge: (i) localized Tm-4f bands introduce intermediate states within the wide gap, narrowing the effective optical band gap; (ii) strong exchange and spin-orbit coupling generate robust local magnetic moments and spin asymmetry in the conduction band; (iii) ELF analysis reveals enhanced covalency and localized electron pockets that stabilize luminescent centers; and (iv) the optical spectra are enriched with visible-range absorption, refractive index resonances, and low-energy plasmon features, while preserving the host's high-energy dielectric robustness. These orbital-engineered modifications establish Tm-doped Ca2SnO4 as a mechanically resilient, optically tunable, and magnetically active phosphor, suitable for red emission in solidstate lighting, intermediate-band photovoltaics, and spin-photon coupling in photonic devices. Our results demonstrate how site-specific rare-earth substitution can unlock multifunctionality in wide-gap stannates, providing a roadmap for designing next-generation spintronic-photonic oxides.