Olive mill wastewater (OMW) represents a toxic waste generated during olive oil production (30 million m³/year). Its phytotoxicity and resistance to biodegradation are mainly due to the presence of polyphenols. Methodologies able to remove these organic compounds from this waste to allow the safe dispose of OMW have been developed, and among them, the most effective are oxidation procedures. In this context, we propose an alternative chemical treatment based on the oxidation of OMW using diluted hydrogen peroxide and seleno-organic compounds (diphenyl diselenide and diseleno-bis-benzoic acid) selected as eco-friendly bioinspired catalysts. The effectiveness of the protocol was monitored by Folin–Ciocalteu (F-C) quantification and NMR quantification. The results demonstrated that the greatest reduction in the total phenols content—up to 96%—was achieved using the highest concentrations of catalyst (0.6% _w/w) and oxidant (10% _v/v). Moreover, a toxicological evaluation was carried out using the marine bacteria Aliivibrio fischeri, revealing a significant decrease in toxicity. The EC₅₀ value increased from 0.089 mg/L in the untreated OMW to 18.740 mg/L in the treated sample after removal of the residual catalyst and peroxides.

The incorporation of selenium into tacrine derivatives has been explored as a novel strategy to enhance therapeutic efficacy while minimizing toxicity in the treatment of neurodegenerative diseases such as Alzheimer’s. This study utilized computational and experimental approaches, including Density Functional Theory (DFT), molecular docking, pharmacokinetic profiling, and toxicological predictions, to evaluate the potential of these derivatives. The selenium-modified compounds demonstrated improved electronic properties, such as narrower HOMO–LUMO gaps and optimized electronegativity, resulting in enhanced stability and reactivity. Pharmacokinetic analyses revealed favorable absorption, distribution, and blood–brain barrier penetration, while toxicological assessments indicated reduced hepatotoxicity and skin sensitization risks compared to tacrine. Molecular docking and dynamic simulations highlighted strong and stable interactions of the derivatives with critical enzymes, including acetylcholinesterase (AChE) and beta-secretases (BACE1 and BACE2). Compounds 12 and 13, in particular, emerged as the most promising candidates due to their superior stability and binding affinity. These findings underscore the potential of selenium-modified tacrine derivatives as safer and more effective therapeutic agents for Alzheimer’s disease, warranting further experimental validation.