The present study reports the synthesis and structural, photophysical and electrochemical properties of five new Schiff bases containing hydantoin rings. The compounds were synthesized via condensation reactions between 3-amino-5,5′-dimethylhydantoin and five different aromatic aldehydes. All compounds were characterized using different spectroscopic and electrochemical tools as well as single crystal X-ray diffraction analysis. The photochromic and molecular switching behaviours of the switchable –CHN– groups of Schiff bases were investigated by real time UV-vis spectroscopy in DMF under long wavelength UV light at λ = 365 nm for 90 min (mostly E → Z) and dark relaxation at room temperature for 60 min (mostly Z → E) in the spectral region of 250 nm to 600 nm at equal concentrations. The electrochemical properties of the compounds were investigated on a glassy platinum electrode (Pt-) in DMF using the cyclic voltammetric (CV) technique before and after UV irradiation. The effects of functional groups on the reduction potential of the Schiff bases are discussed. Electrochemical studies showed that the reduction of –CHN groups is mostly quasi-reversible, with adsorption-controlled processes for (E)-3-((2-hydroxybenzylidene)amino)-5,5′-dimethylimidazolidine-2,4-dione (SB2) and (E)-3-((4-(dimethylamino)benzylidene)amino)-5,5′-dimethylimidazolidine-2,4-dione (SB4) and intermediate processes for the remaining compounds.

Six novel quaternary ammonium derivatives of 4-pyrrolidino pyridine were prepared and isolated via a facile one-pot synthesis and a simple purification procedure. The purity and the molecular structure of the 4-pyrrolidino pyridine derivatives were confirmed with ¹H and ¹³C NMR spectroscopy and powder X-ray diffraction techniques. The crystal structures of the compounds were characterized by single crystal X-ray diffraction (SCXRD) and their thermal properties were studied by Differential Scanning Calorimetry (DSC) analyses. The antibacterial properties of the title compounds against five bacterial strains were evaluated using Kirby–Bauer disk diffusion susceptibility test. The compounds crystallize in the monoclinic or orthorhombic crystal systems (space groups: P2₁/c, P2₁/n, or P2₁2₁2₁) and their crystal structures are stabilized by a combination of intra- and intermolecular halogen bonding interactions, short contacts and π-π interactions. Above interactions, they contribute to the thermal stability and lack of phase transition effects up to 350 °C. Two of the compounds possess antibacterial effect against E. coli or S. aureus bacterial strains—similar or better than the kanamycin reference.

Textile dyes are persistent water pollutants, requiring effective treatment strategies. This study reports the adsorption performance of embryonic zeolite precursors (EZPs) synthesized with tetrapropylammonium hydroxide as a structure-directing agent. The materials were prepared with different Si/Al ratios (50, 100, and 200) in the starting gel and tested for the removal of methylene blue (MB) from aqueous solutions. Comprehensive characterization (PXRD, SAXS, BET, FTIR, EDXRF, N₂ physisorption, and TGA/DSC) confirmed their micro/mesoporous and amorphous nature. Among them, EZTPA50 displayed the highest surface area (915 m² g⁻¹) and hierarchical porosity. Adsorption experiments revealed that EZTPA50 and EZTPA100 outperformed the crystalline counterpart H-ZSM-5. Their monolayer capacities reached 146.08 mg g⁻¹ and 122.62 mg g⁻¹, respectively. Langmuir isotherm modeling indicated monolayer coverage, while Elovich kinetics suggested heterogeneous surface chemisorption. Thermodynamic analysis showed spontaneous, endothermic, and entropy-driven adsorption for both materials. Intraparticle diffusion analysis revealed a multi-stage adsorption mechanism influenced by pore accessibility and surface heterogeneity. Thermal regeneration studies demonstrated that EZ_TPA50 retained ∼90% removal efficiency over four cycles, highlighting its structural stability and reusability. These findings position EZPs – particularly EZ_TPA50 – as promising, regenerable adsorbents for efficient dye removal, offering advantages over conventional microporous zeolites in terms of adsorption capacity, kinetics, and thermal robustness.

Two series of polydentate N,O,S-ligands containing thiourea fragments attached to a p-cresol scaffold, unsymmetrical mono-acylated bis-amines and symmetrical bis-thioureas, are obtained by common experiments. It is observed that the reaction output is strongly dependent on both bis-amine and thiocarbamic chloride substituents. The products are characterized by 1D and 2D NMR spectra in solution and by single crystal XRD. A preliminary study on the coordination abilities of selected products is performed by ITC at around neutral media.

Here, we describe the synthesis, characterization, and biological activities of a series of 26 new styryl-2(3H)-benzothiazolone analogs of combretastatin-A4 (CA-4). The cytotoxic activities of these compounds were tested in several cell lines (EA.hy926, A549, BEAS-2B, MDA-MB-231, HT-29, MCF-7, and MCF-10A), and the relations between structure and cytotoxicity are discussed. From the series, compound (Z)-3-methyl-6-(3,4,5-trimethoxystyryl)-2(3H)-benzothiazolone (26Z) exhibits the most potent cytotoxic activity (IC₅₀ 0.13 ± 0.01 µM) against EA.hy926 cells. 26Z not only inhibits vasculogenesis but also disrupts pre-existing vasculature. 26Z is a microtubule-modulating agent and inhibits a spectrum of angiogenic events in EA.hy926 cells by interfering with endothelial cell invasion, migration, and proliferation. 26Z also shows anti-proliferative activity in CA-4 resistant cells with the following IC₅₀ values: HT-29 (0.008 ± 0.001 µM), MDA-MB-231 (1.35 ± 0.42 µM), and MCF-7 (2.42 ± 0.48 µM). Cell-cycle phase-specific experiments show that 26Z treatment results in G2/M arrest and mitotic spindle multipolarity, suggesting that drug-induced centrosome amplification could promote cell death. Some 26Z-treated adherent cells undergo aberrant cytokinesis, resulting in aneuploidy that perhaps contributes to drug-induced cell death. These data indicate that spindle multipolarity induction by 26Z has an exciting chemotherapeutic potential that merits further investigation.