Proper management of wastewater contaminated with heavy metals through biosorption supports climate change mitigation, green growth, and the circular bioeconomy by generating innovative, biodegradable biosorbents. In this study, lignocellulosic materials derived from residual fennel seeds ( Foeniculum vulgare ), in both virgin (FS) and modified (MFS) forms, were employed for the simultaneous adsorption of Cd, Cr, Cu, and Pb ions from simulated and real wastewaters, for the first time. Physicochemical and instrumental characterisations confirmed the presence of diverse functional groups, high cation exchange capacity, and favourable morphology essential for efficient adsorption. The influence of pH, biosorbent mass, initial concentration, and contact time on the adsorp - tion kinetics and capacity was evaluated. Under optimal conditions (solution pH: 5 (FS)/4 (MFS), initial individual analyte concentration: 50 mg/L, contact time: 20 min with 300 mg of biosorbent), maximum adsorption capacities reached 5.1/7.5 (Cr), 6.1/10.2 (Cu), 3.6/6.7 (Cd), and 7.9/14.7 mg/g (Pb) for FS/MFS, with corresponding removal efficiencies of 50-87.5% (FS) and 50–97.5% (MFS). The metal binding affinity followed the order: Cd < Cr < Cu < Pb. Kinetic analysis revealed a strong correlation with the pseudo-second-order and intraparticle diffusion models (average fit of the removal efficiency values: 99.60% (FS) and 99.85% (MFS), with determination coefficients (R 2 ) close to 1). Overall, the developed biosorption process is cost-effective, environmentally benign, and technically applicable, fully aligning with the principles of green chemistry.

A novel heterobimetallic ruthenium(II)–gold(I) complex featuring a bridging bis(diphenylphosphino)butane (dppb) ligand was prepared and fully characterized. Single-crystal X-ray diffraction revealed a piano-stool geometry around Ru(II) with η6-cymene, two chlorido ligands, and one phosphorus atom from dppb, while the Au(I) center adopts a linear P–Au–Cl coordination. Structural integrity in the solution was confirmed by 1D and 2D NMR spectroscopy, while solution behavior was further monitored by variable solvent 31P NMR and UV/Vis spectroscopy, indicating that the organometallic Ru–arene core remains intact, whereas the chlorido ligands coordinated to Ru exhibit partial lability. Complementary characterization included elemental analysis, FTIR, and UV/Vis spectroscopy. Spectrofluorimetric and FRET analyses showed that Au(dppb), Ru(dppb), and the heterobimetallic AuRu complex bind to BSA with apparent constants of 1.41 × 105, 5.12 × 102, and 2.66 × 104 M−1, respectively, following a static quenching mechanism. In vivo biological evaluation in Wistar rats revealed no significant hepatotoxicity or nephrotoxicity, with only mild and reversible histological alterations and preserved hepatocyte nuclear morphology. Hematological analysis indicated a statistically significant reduction in leukocyte populations, suggesting immunomodulatory potential, while elevated serum glucose levels point to possible endocrine or metabolic activity. These findings highlight compound structural stability and intriguing bioactivity profile, making it a promising platform for further organometallic drug development and testing.

The need for a systematic approach in developing new metal-based drugs with dual anticancer-antimicrobial properties is emphasized by the vulnerability of cancer patients to bacterial infections. In this context, a novel organometallic assembly was designed, featuring ruthenium(II) coordination with p-cymene, one chlorido ligand, and a bidentate neutral Schiff base derived from 4-methoxybenzaldehyde and N,N-dimethylethylenediamine. The compound was extensively characterized in both solid-state and solution, employing single crystal X-ray diffraction, nuclear magnetic resonance, infrared, ultraviolet-visible spectroscopy, and density functional theory, alongside Hirshfeld surface analysis. The hydrolysis kinetic was thoroughly investigated, revealing the important role of the chloro-aqua equilibrium in the dynamics of binding with deoxyribonucleic acid and bovine serum albumin. Notably, the aqua species exhibited a pronounced affinity for deoxyribonucleic acid, engaging through electrostatic and hydrogen bonding interactions, while the chloro species demonstrated groove-binding properties. Interaction with albumin revealed distinct binding mechanisms. The aqua species displayed covalent binding, contrasting with the ligand-like van der Waals interactions and hydrogen bonding observed with the chloro specie. Molecular docking studies highlighted site-specific interactions with biomolecular targets. Remarkably, the compound exhibited wide spectrum moderate antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, coupled with low micromolar cytotoxic activity against human colorectal adenocarcinoma cells and significant activity against human leukemic monocyte lymphoma cells. The presented findings encourage further development of this compound, promising avenues for its evolution into a versatile therapeutic agent targeting both infectious diseases and cancer.

Solution synthesis afforded five novel neutral heteroleptic octahedral paramagnetic mononuclear oxidovanadium(IV) complexes of general composition [VO(bpy)L], where L is a dianionic tridentate ONO-donor hydrazone ligand derived from 2-furoic acid hydrazide and salicylaldehyde and its 5-substituted derivatives. Characterization was carried out by elemental analysis, mass spectrometry, infrared, electron, NMR, and EPR spectroscopy, cyclic voltammetry and conductometry. The molecular and crystal structure of the complex with 5-chloro-salicylaldehyde 2-furoic acid hydrazone (2) was determined. The quantum chemical properties of the vanadium complexes were studied at B3LYP and M062X levels with the lanl2dz basis set using Gaussian. Additionally, Swiss-ADME analysis was performed and complex (4), featuring a 5-nitro substituent on the hydrazone ligand, was selected for further investigation. The effects of the in vivo application of the complex on selected biochemical parameters in healthy and diabetic Wistar rats were investigated. Strong antidiabetic effect associated with moderate hypoalbuminemia was observed. Furthermore, the interaction of complexes with BSA was studied by spectrofluorimetry. A significant conformational change of BSA in the presence of vanadium complexes was found. Synchronous fluorescence spectra revealed significant changes in the tyrosine microenvironment of BSA. The FRET analysis was also used and the non-radiative process of energy transfer is elucidated. Thermodynamic data suggest van der Waals forces and hydrogen bonding as predominant binding modes of complexes to BSA.

Black cumin (Nigella sativa L. [N.sativa]) seed extracts demonstrated numerous beneficial biological effects including, among others, antidiabetic, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, antihypertensive, and antioxidant activity. To better understand the phytochemical composition of N. sativa seeds, methanol seed extracts were analyzed for phenolic acid and flavonoid content. Furthermore, we tested N. sativa methanol, n-hexane, and aqueous seed extracts for their inhibitory activity against butyrylcholinesterase (BChE) and catalase (CAT) as well as for antimicrobial activity against several bacterial and a yeast strains. The phenolic content of N. sativa was analyzed using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The inhibition of BChE was assessed by modified Ellman's method, and the inhibition of CAT was determined by monitoring hydrogen peroxide consumption. The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, and Escherichia coli using the agar diffusion method. The UHPLC-MS/MS method allowed the identification and quantification of 23 phenolic compounds within 15 minutes. The major components found in N. sativa seed extract were sinapinic acid (7.22 ± 0.73 µg/mg) as a phenolic acid and kaempferol (11.74 ± 0.92 µg/mg) as a flavonoid. All extracts showed inhibitory activity against BChE, with methanol seed extract demonstrating the highest inhibitory activity (inhibitory concentration 50% [IC50] 79.11 ± 6.06 µg/ml). The methanol seed extract also showed strong inhibitory activity against CAT with an IC50 value of 6.61 ± 0.27 µg/ml. Finally, the methanol extract exhibited considerable inhibitory activity against the tested microbial strains. Overall, this is the first study to investigate the ability of black cumin seed extracts to inhibit CAT. Our results indicate that N. sativa seed can be considered as an effective inhibitor of CAT activity.