The analysis of stability of biologically active compounds requires an accurate determination of their structure. We have found that 5-aryl-3-(2-aminoethyl)-1,2,4-oxadiazoles are generally unstable in the presence of acids and bases and are rearranged into the salts of spiropyrazolinium compounds. Hence, there is a significant probability that it is the rearranged products that should be attributed to biological activity and not the primarily screened 5-aryl-3-(2-aminoethyl)-1,2,4-oxadiazoles. A series of the 2-amino-8-oxa-1,5-diazaspiro[4.5]dec-1-en-5-ium (spiropyrazoline) benzoates and chloride was synthesized by Boulton–Katritzky rearrangement of 5-substituted phenyl-3-[2-(morpholin-1-yl)ethyl]-1,2,4-oxadiazoles and characterized using FT-IR and NMR spectroscopy and X-ray diffraction. Spiropyrazolylammonium chloride demonstrates in vitro antitubercular activity on DS (drug-sensitive) and MDR (multidrug-resistant) of MTB (M. tuberculosis) strains (1 and 2 µg/mL, accordingly) equal to the activity of the basic antitubercular drug rifampicin; spiropyrazoline benzoates exhibit an average antitubercular activity of 10–100 μg/mL on MTB strains. Molecular docking studies revealed a series of M. tuberculosis receptors with the energies of ligand–receptor complexes (−35.8–−42.8 kcal/mol) close to the value of intermolecular pairwise interactions of the same cation in the crystal of spiropyrazolylammonium chloride (−35.3 kcal/mol). However, only in complex with transcriptional repressor EthR2, both stereoisomers of the cation realize similar intermolecular interactions.

The escalating demand for precious metals in high-tech industries and jewelry, combined with the depletion of their reserves, underscores the need for efficient methods of gold recovery from industrial effluents. An interpolymer system comprising industrial ion exchangers KU-2-8 (in H⁺ form) and AV-17-8 (in OH⁻ form) demonstrated strong selective sorption capacity for Au(I) ions from a simulated Au(I)/Fe(II) mixed solution. The optimal KU-2-8:AV-17-8 (3:3) system achieved a sorption efficiency of 97.0% for Au(I) ions after 48 h with a desorption efficiency of 98.0% using a thiourea/sulfuric acid solution. The distribution coefficient (K_d) for Au(I) ions reached a maximum of 3233.3 mL/g at the 3:3 ratio, with a separation coefficient (β) of 40.62, indicating exceptional selectivity over Fe(II) ions. Fourier-transform infrared (FTIR) spectroscopy revealed structural changes post-sorption, including shifts in absorption bands (e.g., from 1273.5 cm⁻¹ to 1292.9 cm⁻¹) and the appearance of new bands (e.g., at 3171.1 cm⁻¹), confirming stable ion interactions. Thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) demonstrated enhanced thermal stability post-sorption, with reduced mass loss up to 100 °C. These findings highlight the KU-2-8:AV-17-8 (3:3) interpolymer system’s high selectivity, robust sorption capacity, and efficient desorption, presenting a sustainable solution for gold recovery in hydrometallurgical applications.

Background and Aim: Tuberculosis (TB) remains a significant global health challenge, with increasing incidences of drug-sensitive (DS) and multidrug-resistant (MDR) TB. In addition, Mycobacterium bovis-induced zoonotic TB (zTB) presents treatment difficulties due to its resistance to pyrazinamide and the prolonged treatment duration required. This study aims to evaluate the antitubercular potential of β-aminopropioamidoxime derivatives against DS and MDR Mycobacterium tuberculosis and M. bovis strains, and utilizing the SwissADME prognostic tool to predict the drug- and lead-likeness of the described compounds. Materials and Methods: Six β-aminopropioamidoxime derivatives were synthesized through O-aroylation of amidoxime followed by dehydration to form 1,2,4-oxadiazoles. The compounds were tested in vitro against DS, MDR M. tuberculosis, and M. bovis using Sotton’s liquid medium and subcultured on dense Lowenstein-Jensen medium. SwissADME was used to predict drug-likeness and pharmacokinetic properties. Results: The derivatives exhibited significant antitubercular activity, with in vitro efficacy 5–100 times greater than rifampicin. 1,2,4-oxadiazoles with para-bromo and meta-chloro substituents demonstrated the highest activity against DS and MDR M. tuberculosis, while O-para-toluoyl-β-(morpholin-1-yl)propioamidoxime salts (hydrochloride, oxalate and citrate) were 10 times more active against M. bovis. SwissADME analysis confirmed favorable pharmacokinetic properties, including high gastrointestinal absorption and drug-likeness, with lead-likeness identified in four compounds. Conclusion: The study presents β-aminopropioamidoxime derivatives as promising candidates for antitubercular therapy against both human and zTB. Their enhanced activity, oral bioavailability, and potential integration into new treatment regimens underscore their therapeutic relevance. Further in vivo studies are recommended to validate their efficacy and safety for clinical applications. Keywords: antitubercular agents, Mycobacterium bovis, Mycobacterium tuberculosis, SwissADME, tuberculosis, β-aminopropioamidoximes.

This study presents a method for the efficient separation of gold and iron ions using cross-linked polyelectrolyte interpolymer systems. The research aims to investigate the sorption behavior resulting from the remote interaction of intergel systems based on polymethacrylic acid (gPMAA) and poly-4-vinylpyridine (gP4VP) hydrogels. According to the atomic emission spectroscopy results, the individual gPMAA (6:0) hydrogel exhibits negligible activity toward gold ions, with a sorption degree of only 5.97%, while maintaining a high sorption efficiency for iron ions at approximately 90.27%. The interpolymer interaction effect is most pronounced in the equimolar (3:3) intergel system, where the sorption efficiency for gold ions significantly increases, reaching a peak of 63.97% after 24 h of contact. In contrast, the sorption efficiency for iron ions remains consistently high across all molar ratios, fluctuating between 88.27% and 91.33%. The polymer chain binding degree (θ) further confirms these trends, reaching maximum values of 1.09% for gold and 7.18% for iron ions. These findings demonstrate that the gPMAA-gP4VP system possesses a high selective affinity for iron over gold under the studied conditions, providing a viable approach for the selective separation and recovery of metals from multicomponent industrial solutions.