Aminopterin

Methotrexate (MTX), a widely used anticancer drug, is a refractory organic pollutant posing serious threats to ecosystems and human health.This study focuses on the development of a novel catalyst composed of Ce-based high-entropy metal oxides (NHEMO) supported on nepheline for the catalytic wet peroxide oxidation (CWPO) process, targeting MTX degradation in simulated wastewater.The NHEMO catalyst exhibited a unique high-entropy structure that enhances catalytic performance by facilitating diverse electronic interactions, which was confirmed through X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses showing a well-defined crystal structure and uniform dispersion of metal oxides.Addnl., XPS and energy-dispersive X-ray spectroscopy (EDS) revealed a stable metal composition and high oxidation states of active metal sites.At a reaction temperature of 160 °C, with a residence time of 150 s and an oxidation coefficient of 5, the catalyst achieved a MTX removal rate of 93.49 % and a COD (COD) removal of 99.95 %.D. Functional Theory (DFT) calculations further demonstrated that H2O2 decomposes into both adsorbed (surface-bound) and free (solution-phase) hydroxyl radicals (.OH).These radicals synergistically degrade MTX through both radical and non-radical pathways, ensuring comprehensive pollutant breakdown.The catalyst also showed excellent stability and a very low metal dissolution rate during the reaction, maintaining high catalytic activity after repeated recycling.This catalyst offers high cost-effectiveness, activity, and stability, providing a promising solution for treating refractory organic pollutants in pharmaceutical wastewater.

Native electrospray ionization mass spectrometry (ESI-MS) is a standard technique for drug-protein screening but may be affected by nonspecific binding. To address this, a reference protein and ligand must be selected for each protein investigated. We report a versatile, informative, high-throughput screening approach to differentiate specific and nonspecific interactions based on charge state distribution (CSD) changes caused by ionization perturbations (e.g., methanol or heat) without the need for a surrogate. We show that specific binding stabilizes the protein-ligand complex against perturbations, resulting in narrower CSDs compared with the unbound protein. In contrast, no significant difference in CSDs is observed between nonspecific complexes and the free protein. To introduce ion source perturbations without affecting protein-ligand incubation, we employed a 3D-printed open port probe (OPP) that is widely compatible with different instruments and sample introduction techniques. The approach was validated with well-characterized protein-ligand pairs, confirming that cytidine phosphates, triacetylchitotriose, and fluvastatin are specific ligands for ribonuclease A, lysozyme, and beta-lactoglobulin, respectively. Further, cytidine-5'-triphosphate (CTP) was found to interact nonspecifically with lysozyme and beta-lactoglobulin. The approach was applied to screening assays of two drug target proteins, thrombin and dihydrofolate reductase, revealing that for thrombin, fluvastatin may share the same binding site as argatroban, which is supported by competition experiments and molecular docking results. These results provide new insights into the anticoagulation effect of statins and show the potential of the approach in prioritizing candidates for target proteins.