Mustafa Yilmaz

In this study, covalent organic frameworks (COFs) were synthesized from triazine and 2-aminoterephthalic acid, and their amino groups were functionalized with S-naproxen (S-NPX) to produce chiral COFs (COF/NPX) for the first time. Candida rugosa lipase (CRL) was immobilized onto the chiral COF, yielding COF/NPX/CRL, and its catalytic performance was evaluated through the hydrolysis of p-nitrophenyl palmitate (p-NPP) and the kinetic resolution of racemic naproxen methyl ester. To investigate the effect of chiral modification, a non-functionalized control biocatalyst (COF/CRL) was also prepared and comparatively evaluated. The synthesized COFs and immobilized lipase systems were characterized using FTIR, SEM, EDX, XRD, and BET analyses. Under optimized reaction conditions, COF/NPX/CRL exhibited significantly improved enantioselectivity and conversion, achieving 94% enantiomeric excess (ee_s) and 50% conversion, compared with 72% ee_s and 40% conversion for COF/CRL. Kinetic analysis further revealed that COF/NPX/CRL possessed a higher Vmax and lower Km than the control system, indicating enhanced catalytic efficiency and substrate affinity. The improved performance was attributed to the chiral environment introduced by S-NPX functionalization, which positively influenced the immobilized enzyme’s catalytic behavior and enantioselectivity. Moreover, the chiral biocatalyst maintained good stability under demanding reaction conditions, demonstrating the robustness of the COF support. Overall, these findings show that S-NPX-functionalized COF provides an effective, stable, and chiral support for CRL immobilization, significantly enhancing catalytic activity and enantioselectivity. COF/NPX/CRL therefore represents a promising platform for enzymatic kinetic resolution, production of chiral compounds, and advanced biocatalyst design.

Introduction: Calix[n]arenes can be selectively functionalized more easily than other cyclic supramolecules such as crown ethers and cyclodextrins. 1,8-Naphthalimide derivatives of calix[ 4]arenes are very important and versatile fluorophores widely used in fluorescence detection due to their high absorption coefficients, strong fluorescence, high quantum yields, large Stokes shifts, excellent photostability. Materials and Methods: Two Calix[4]arene-based fluorescent probes were synthesized for the detection of Cu2+ and F-. The fluorescence properties of the compounds were evaluated in the presence of various cations and anions using spectroscopic techniques. Their cytotoxicity was tested in Hep-2 and HeLa living cells. Results: The synthesized calix[4]arene derivatives were evaluated in the presence of various cations and anions using different spectroscopic and analytical techniques. In the tests, the fluorescence intensity of 7 decreased significantly in the presence of Cu2+ or F-. A similar quenching effect was observed for 6 only in the presence of Cu2+. The cytotoxic properties of calix[4]arene derivatives were evaluated against Hep-2 and HeLa living cells. The results showed significant cytotoxicity of compounds 6 and 7. Discussion: Confocal microscopy studies revealed that these compounds exhibited strong intracellular fluorescence, indicating efficient cellular uptake by cells. In the presence of Cu2+ or F-, the fluorescence intensity of the diamide derivative decreased significantly, which was attributed to the complexation effect between the ligand and the corresponding ions. Conclusion: Monoamide derivative 6 has the potential to be a fluorescent sensor for Cu2+, and diamide derivative is a fluorescent sensor for Cu2+ and F- ions. Cells treated with compounds 6 or 7 exhibited high intracellular fluorescence.

Introduction: This study introduces a previously unreported sulfonated Naphthalimide derivative (NAP) designed as a multifunctional molecular scaffold for integrated fluorescence sensing and antimicrobial applications. Following functionalization with 3-(methylthio)propylamine, the compound was successfully immobilized onto silver nanoparticles (AgNPs) via thiomethyl anchoring, yielding a stable and highly functional nanohybrid system. The photophysical characteristics and selective metal ion sensing behavior of the resulting NAP-AgNPs were systematically evaluated. Importantly, this work constitutes the first example of sulfonate-bearing naphthalimide-functionalized AgNPs that simultaneously act as nanoparticle stabilizers, fluorescent sensing elements, and antimicrobial agents, thereby establishing a new multifunctional strategy for naphthalimide-silver nanomaterials Methods: NAP was synthesized via the reaction of 4-sulfo-1,8-naphthalic anhydride with 3- (methylthio)propylamine and subsequently immobilized onto AgNPs through its thiomethyl groups. Structural and morphological characterizations were performed using NMR, FTIR, SEM, XRD, and DLS techniques. Photophysical properties were investigated by UV-Vis and fluorescence spectroscopy. Interaction studies with Cd2+, Mn2+, Cu2+, Co2+, Ni2+, Zn2+, Fe2+, Fe³⁺, Pb2+, Hg2+, and Ag⁺ ions were carried out. Antimicrobial activity was assessed against Gram- positive and Gram-negative bacteria. Results: NAP exhibited strong fluorescence emission at 520 nm, while NAP-AgNPs showed surface plasmon resonance with complete fluorescence quenching. Selective optical responses to Fe2+, Fe³⁺, Hg2+, and Ag⁺ were observed in both UV-Vis and fluorescence spectra, indicating promising sensing ability. Additionally, NAP-AgNPs displayed significant antimicrobial activity Discussion: The study demonstrates that sulfonated NAP derivatives can serve as sensitive and selective probes for specific metal ions. The incorporation into AgNPs provided unique plasmonic properties, which may enhance sensing applications and enable dual-functional materials with antimicrobial capability. Conclusion: This work highlights the potential of NAP and NAP-AgNPs as photofunctional materials for selective metal ion sensing and as effective antimicrobial agents, suggesting future applications in environmental monitoring and biomedical fields.

Naproxen is a widely used Non-Steroidal Anti-Inflammatory Drug (NSAID) and is notable for its analgesic, antipyretic and anti-inflammatory properties. It shows its pharmacological effect by inhibiting Cyclooxygenase (COX) enzymes and suppressing prostaglandin synthesis. This mechanism plays an important role in reducing inflammation and controlling pain. The pharmacokinetic properties, bioavailability and side effect profile of naproxen are the determining factors in the selection of synthesis methods. In recent years, factors such as environmental sustainability and stereoselectivity have become increasingly important in the synthesis of S-naproxen, and enzymatic synthesis methods have gained prominence. Enzymatic processes offer high stereoselectivity, providing the advantage of producing S-naproxen in the preferred enantiomer form. Moreover, the use of biocatalysts reduces energy consumption by making the reaction conditions milder and avoiding the use of toxic reagents for an environmentally friendly production process. The review focuses on the chemical structure, pharmacological effects, biotransformation mechanisms, and enantiomeric properties of naproxen. The review also includes current formulation approaches to address solubility and bioavailability issues of naproxen. This review contributes to the understanding of current strategies to enhance the therapeutic efficacy of naproxen and highlights potential areas for future research.

Summary Breast cancer remains a leading global health challenge, driving the urgent need for innovative therapeutic strategies. This study presents the initial results of the design, synthesis, characterization, and in vitro evaluation of a novel fluorescent agent for breast cancer treatment, focusing on its subcellular localization and molecular docking. Seven novel fluorescent compounds (3a–g) were synthesized via isatin derivatives and 4-bromo 1,8-naphthalimide conjugation. The compounds were spectroscopically characterized and tested in MDA-MB-231 and MCF-7 cells using viability assays, Annexin-V and propidium iodide flow cytometry to define cytotoxic mechanisms, confocal microscopy with nuclear and mitochondrial markers for subcellular localization, and molecular docking to VEGFR2 (4AGD) and KIT (3G0E) as co-crystals. 3a (3,85 µM and 2,99 µM) and 3c (1,77 µM and 77,31 µM) emerged as two candidates with high cytotoxic potential, exhibiting the lowest IC₅₀ values in MCF-7 and MDA-MB-231 cell lines, respectively, at the 24^th hour. Several conjugates, particularly 3a (87.47 %) and 3 g (96.62 %) in MCF-7, induced late apoptosis, and 3c (98.57 %) in MDA-MB-231 induced the highest early apoptosis. Across both proteins (3G0E and 4AGD), 3c consistently shows stronger predicted binding than sunitinib, with more negative binding energies and lower Ki values in each case, supporting its promise as a lead together with 3a.