Elvan Hasanoğlu Özkan

Herein, novel heterocyclic thiosemicarbazone compounds (Hb ₁ , Hb ₂ , Hb ₃ ) containing pyrimidine, imidazole, pyridine, and phenyl rings were synthesized via the condensation method as potential therapeutic agents for the treatment of non-small cell lung cancer. The structure of novel heterocyclic compounds was elucidated by using some spectroscopic techniques (organic elemental analysis, fourier transform infrared spectroscopy, proton/carbon nuclear magnetic resonance spectroscopy, scanning electron microscopy and energy dispersive X-ray image, and molar conductance measurement). The antiproliferative activity of novel heterocyclic thiosemicarbazone compounds using CVDK-8 cell viability assay. The viability assay was examined against A549 human non-small cell lung cancer cell line. All heterocyclic thiosemicarbazone compounds exhibited varying degrees of dose-dependent cytotoxic activity against A549 NSCLC cells. The results showed that the pyridine-based heterocyclic compound (Hb ₃ ) was the most potent antiproliferative agent, demonstrating a dose-dependent reduction in cell viability at concentrations of 50 µg/mL and higher.

Pyrazole derivatives have attracted considerable interest in medicinal chemistry as adaptable frameworks for developing cholinesterase inhibitors, owing to their advantageous physicochemical properties and structural flexibility. The heteroaromatic characteristics of the pyrazole core allow for various substitution patterns, promoting selective interactions with both the catalytically active site (CAS) and the peripheral anionic site (PAS) of cholinesterase enzymes. These attributes enable pyrazole-based drugs to be viable candidates for the therapy of cognitive disorders, especially Alzheimer’s disease. This study aims to systematically describe medicinal chemistry studies on pyrazole-based cholinesterase inhibitors conducted from 2020 to 2025. The focus is on structural alterations of the pyrazole core and their impact on the inhibitory action against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using structure–activity relationship (SAR) analysis. Recent advancements in in vitro enzymatic inhibition studies, molecular docking, kinetic analysis, ADME predictions, and multi-target-directed ligand (MTDL) techniques are rigorously evaluated to elucidate trends in potency, selectivity, and drug-like characteristics based on information retrieved from three search engines: Scopus, PubMed, and Google Scholar. This review addresses significant challenges in pharmacokinetics, blood–brain barrier permeability, and safety while delineating prospects for integrating rational design, computational modeling, and biological validation to expedite the development of clinically relevant pyrazole-based cholinesterase inhibitors for Alzheimer’s disease.

Herein, a novel amperometric biosensor was developed for the sensitive determination of cholesterol. For this purpose, silane-modified graphene oxide/polymer hybrid nanocomposite (SiGOP _nc ) was obtained by the reaction of 3-chloropropyl functionalized silica gel, 4-formyl-3-methoxy-phenoxymethyl polystyrene, and 4-methyl-3-thiosemicarbazide. The novel SiGOP _nc hybrid nanocomposite was characterized using spectroscopic methods, including elemental analysis, FT-IR, GPC, SEM-EDX, and XPS. Then, the GCE/SiGOP _nc @CS@AuNPs modified electrode was prepared, and the electrochemical properties of GCE/SiGOP _nc @CS@AuNPs were characterized using Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Cholesterol oxidase enzyme (ChOx) was immobilized on the GCE/SiGOP _nc @CS@AuNPs electrode by cross-linking with glutaraldehyde and BSA. The determination of ChOx was carried out based on the oxidation of hydrogen peroxide at 0.5 V, formed as a result of the enzymatic reaction on the surface of the prepared biosensor (GCE/SiGOP _nc @CS@AuNPs/ChOx). The cholesterol biosensor exhibited a linear working range of 0.5 μM to 100 μM. The LOD value was found to be 0.18 μM. After 17 measurements, it was also determined that the performance of the electrochemical biosensor was preserved at 72.5%. The developed novel electrochemical biosensor was successfully applied to the selective and sensitive detection of cholesterol.

The emergence of antibiotic‐resistant bacteria represents one of the most pressing challenges in global healthcare. In this study, metal oxide–based nanomaterials are gaining prominence due to their antimicrobial and anticancer potential. In the present study, six new zinc oxide nanoparticles (ZnO‐NPs) synthesized via the hydrothermal method using different surfactants were characterized, and their biological activities were evaluated. ZnO‐NPs, whose structural properties were determined by a range of analytical methods including BET, FT‐IR, SEM‐EDX, XRD, and XPS, exhibited significant antibacterial and antifungal effects on a range of bacterial and fungal strains. The study revealed that variations in the morphology and surface area had a direct impact on antimicrobial efficacy. In antimicrobial assays, the inhibition zones ranged from 10.5 mm to 25.5 mm, with ZnO‐6 exhibiting the highest efficacy against S. epidermidis (25.5 mm). In cytotoxicity assays, ZnO‐6 demonstrated the strongest anticancer potential against H460 cells with the lowest IC ₅₀ value of 31.9 µg/mL. Furthermore, a strong correlation was revealed between the physicochemical properties of ZnO‐NPs and their anticancer activity, as evidenced by the results of tests conducted on H460 lung cancer cells. Specifically, ZnO‐6, which possesses a flower‐like morphology and the highest surface area, exhibited the strongest anticancer effect with an IC ₅₀ value of 31.9 µg/mL. The parallel enhancement in both antimicrobial and anticancer activities observed in ZnO‐6 suggests a common underlying mechanism, likely driven by the high surface area and specific flower‐like morphology that facilitates increased interaction with cell membranes and ROS generation. The findings demonstrate that the controlled design of ZnO‐NPs in terms of morphology and surface area offers significant potential in both antimicrobial and anticancer applications.

Nanoparticles are often referred to as miracle materials with extensive applications in various fields, especially in biomedicine, and in cancer treatment. Regarding vast applications of nanoparticles in biomedicine, photothermal therapy (PTT) also attracts the attention of researchers in various fields, since PTT is noninvasive and can provide localized therapy. We provide an extensive review that explores the use of various nanoparticles, including carbon-based, metallic, semiconductor, and composite nanostructures, in PTT and theranostic applications. The work also illustrates the mechanisms underlying the photothermal conversion process in nanomaterials, which were discussed in detail. Moreover, the review demonstrates recent advancements in photothermal nanoparticles such as surface modifications, PEGylation, polydopamine coating, composite nanoparticle formations, core@shell formations, and biomolecule functionalization. Such advancements and modifications enhance their drug delivery behaviors, tumor-targeting efficiency, biocompatibility, and multimodal characteristics. Furthermore, such modifications lead to combined imaging and therapeutic functionalities, which were often referred to as theranostics where magnetic resonance imaging (MRI), X-ray computed tomography (CT) and photoacoustic imaging (PAI) enables precise monitoring and treatment of tumors simultaneously. The review gives an insight into the potential of photothermal nanoparticles and enables researchers to truly discover the potential of the photothermal nanoparticles for future research directions where photothermal nanoparticles can find practical applications in nanomedicine and cancer therapy.

A new magnetic solid phase extraction method was developed utilizing magnetically enhanced zinc oxide (ZnO@Fe₃O₄) nanoparticles for the separation and enrichment of lead (II) and cadmium (II) before sample determination through flame atomic absorption spectrometry. The ZnO@Fe₃O₄ nanoparticles synthesized by the hydrothermal method were characterized by x‐ray diffraction, scanning electron microscopy, and energy‐dispersive x‐ray spectroscopy. The experimental factors like pH (6.0), eluent type and concentration (1 M nitric acid for lead (II), 1 M hydrochloric acid for cadmium (II)), adsorbent amount (150 mg for lead (II), and 200 mg for cadmium (II)), sample volume (5 mL), and extraction time (5 min for lead (II), and 10 min for cadmium (II)) were optimized. Under the optimization conditions, limits of detection of 2.36 and 7.86 µg/L for lead (II) and cadmium (II) were obtained with a wide concentration range from 50 to 5000 µg/L, respectively. The presented method was successfully applied to real water samples with spiked recoveries in the range of 99.2%–101% for lead (II) and 99.6%–100% for cadmium (II).

In this paper, eight novel α-N-heterocyclic thiosemicarbazone complexes were synthesized in search of new biologically active compounds, and characterized via¹H-NMR, IR, TGA, UV-Vis, molar conductance and magnetic susceptibility measurements.

In the present work, novel heterocyclic thiazole-based thiosemicarbazone Ag(I) complexes (Hc1, Hc2, Hc3) were obtained using the template method. The structures of synthesized thiosemicarbazone compounds were determined by some spectroscopic techniques (element analysis, infrared spectra (IR), thermogravimetric analysis (TGA), organic elemental analysis, and magnetic susceptibility measurements). The biological activities of novel heterocyclic thiazole-based thiosemicarbazone Ag(I) complexes werev screenedv in vitro against selected disease-causing pathogens (Micrococcus luteus ATCC9341, Staphylococcus epidermidis ATCC12228, Bacillus cereus RSKK863, Pseudomonas aeroginosa ATCC27853, Klebsiella pneumonia ATCC27853, Enterobacter aerogenes ATCC51342, Salmonellav typhi H NCTC9018394, Shigella dysenteria NCTC2966, Proteus vulgaris RSKK96026, Candidav albicans Y-1200-NIH) were as potential antimicrobial agents. It was determined that the thiazole-based thiosemicarbazone Ag(I) complexes exhibited high or moderate antibacterial and antifungal activity.

Free enzymes cause difficulties in many applications due to their insufficient stability, loss of activity in a short time, and most importantly, although they are costly, they are used only once in reactions, lose their effect and cannot be recovered from the environment. Magnetic nanoparticles coated with biocompatible polymeric material are potential candidates for promising enzyme carriers due to their multifunctional pore surfaces, easy removal from the environment provided by the magnetization, ability to main stability under various harsh conditions. This study prepared a biosensor candidate based on the inhibiting acetylcholinesterase enzyme by organophosphate pesticides from chitosan-coated magnetic nanoparticles doped with gold. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction diffractometry, and Fourier transform infrared spectroscopy analysis confirmed the structure of synthesized nanocomposites. Magnetic characteristics of the nanocomposites were assessed using VSM. Bio-nanocomposite (Fe3O4@Cht/Au/AChE) was used to determine environmental pollutants qualitatively. Remediation of organophosphate-containing wastewater is an essential issue for environmental sustainability. In this work, Dichlorvos and Chlorpyrifos were selected as organic pollutants to assess the enzymatic activity of immobilized Fe3O4@Cht/Au/AChE. Optimum conditions for AChE enzyme were immobilized nanostructures (Fe3O4@Cht/Au/AChE) were determined. The optimum pH for the immobilized enzyme was found to be 8, and the optimum temperature was found to be 60 degrees C. Retained immobilized enzyme activity is found to be around 50% for the 20th reuse. In the presence of 150 mu L pesticide, retained immobilized enzyme activity is found to be around 25%. Method validation was performed for pesticides. When using immobilized AChE, the LOD (limit of detection)-LOQ (limit of quantitation) values for Dichlorovos and Chlorpyrifos was obtained in the range of 0.0087-0.029 nM and 0.0014-0.0046 nM, respectively. The relative standard deviation (RSD%) values, which are indicators of precision, were found to be below 2%.