To study the nature of the interaction in the PbSe-MnSe system, alloys were synthesized in a wide range of concentrations and studied using differential-thermal analysis (DTA), X-ray diffraction (XRD) and microstructural analysis (MSA), as well as density and microhardness measurements. A T-x phase diagram was constructed. It was established that the phase diagram of the PbSe-MnSe system is a quasi-binary section of the ternary Pb-Mn-Se system. A study of the phase equilibrium revealed that a compound containing PbMnSe2 in a 1:1 component ratio is formed in the PbSe-MnSe system. The PbMnSe2 compound melts congruently at 1150 degrees C. X-ray diffraction analysis showed that the PbMnSe2 compound crystallizes in the tetragonal crystal system with the unit cell: a = 13.97; c = 8.20 & Aring;, density rho_pycn = 5.62 g/cm3, rho X-ray = 5.66 g/cm3. It was found that in the system at room temperature, the solid solution content of PbSe-based solid solutions contain up to 5 mol. % MnSe, while that of MnSe-based solid solutions reaches 2.5 mol. % PbSe. Co-crystallization of PbSe and PbMnSe2 compounds ends at the eutectic point containing 25 mol. % MnSe, at 850 degrees C. Another eutectic is formed between PbMnSe2 and gamma- MnSe with a content of 60 mol. % MnSe, temperature 960 degrees C.
Pyrimidine-based derivatives are widely recognized for their diverse biological functions, which arise from their distinctive chemical structures and broad spectrum of pharmacological activities. Consequently, they have attracted sustained interest in the fields of heterocyclic chemistry and medicinal chemistry. From this perspective, the present article highlights innovative synthetic approaches to a wide range of pyrimidine-based compounds, emphasizing their therapeutic significance in the treatment of various diseases, including cancer, infectious diseases and metabolic disorders, as well as recent advances in pharmacological research. The review discusses the development and application of pyrimidine derivatives as anti-tuberculosis and anti-inflammatory agents, alongside their emerging potential as antitumor compounds. In the context of the twenty-first century, the growing prevalence of drug-resistant bacterial infections, which pose a serious threat to global health, underscores the urgent need for novel antibacterial agents. Pyrimidine-containing compounds represent a promising class of candidates in this regard. Moreover, because the pyrimidine scaffold constitutes a key structural motif in many endogenous biomolecules, pyrimidine derivatives possess a strong ability to interact with genetic material, enzymes and other cellular biopolymers. Accordingly, this article provides a comprehensive overview of recent literature on the synthesis, biological evaluation and therapeutic applications of pyrimidine-based drugs. The presented material also summarizes literature data on clinically important pharmaceuticals derived Pralsetinib, Nilotinib, Imatinib, Brodimoprin and Eprizole, which are widely used in the treatment of infectious and non-infectious diseases, as well as in antibiotic, antitumor, antiviral, anticancer and antiinflammatory therapies.
The aim of this study was to synthesize new complexes and evaluate their activity against some bacterial strains. Ciprofloxacin was used as a positive antibacterial control. Complexes were synthesized by the interaction of dipotassium tartrate (Tar) and 4-aminoantipyrine (4-AAP) ligands as mixed ligands with metal chlorides in ethanol media in a molar ratio of L1:M:L2 (1:1:1). FT-IR spectral data revealed shifts in the nu(C=O), nu(N-H) and nu(COO-) carboxylic bands, confirming that the ligands coordinate to the metal ion center through both the carbonyl oxygen and amine nitrogen atoms for 4-AAP and dicarboxylic groups for (Tar), acting as bidentate donors. Additionally, water was found to participate in coordination, completing the metal's coordination sphere. The general formula of the synthesized compounds was K[M(Tar)(4-AAP)(H2O)Cl], where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The complexes were characterized by FTIR, 1H NMR, 13C NMR spectroscopy, magnetic susceptibility, atomic absorption and molar conductivity. The geometric shape of the complexes is consistent with the octahedral shape. Calculations for this study were carried out using the Gaussian 09 program package coupled with the DFT technique to optimize different complexes with the B3LYP/LANL2DZ basis set and quantum chemical calculations of various quantum chemical descriptors were calculated using density functional theory (DFT).
Aryl-and heteroaryl-hydrazone derivatives are recognized scaffolds with diverse biological activities, including antimicrobial, anti-inflammatory and antiviral effects. In this study, four alpha-keto acid-based arylhydrazone esters were evaluated using an integrated in silico workflow combining molecular docking, multitarget activity prediction, drug-repositioning analysis and toxicity assessment to explore their potential as SARS-CoV-2 main protease (Mpro) inhibitors. Docking simulations using SwissDock indicated that all compounds interacted with key catalytic residues, forming recurrent hydrogen bonds with Glu166 and Gly143 and hydrophobic contacts within the S1/S2 subsites. The 3,5-dimethyl-substituted derivative showed the most favorable docking score (Delta G =-5.17 kcal/mol), although the differences among the series were modest and should be interpreted cautiously. Multitarget profiling suggested additional interactions with enzymes related to inflammation and metabolic regulation, while toxicity predictions indicated generally acceptable acute oral risk with some route-dependent variability. Taken together, the results support these hydrazone esters as hypothesis-generating leads rather than confirmed antivirals. The contrasting outcomes between broader antiviral prediction models and SARS-CoV-2-specific QSAR tools highlight the importance of model specificity and the need for experimental validation. Overall, the present findings provide a computational basis for prioritizing arylhydrazone scaffolds for further optimization and biological testing.
This paper presents the results of a comprehensive study of solid-phase equilibria in the Bi2S3-Bi2Se3-BiI3 system and the thermodynamic properties of the intermediate phases Bi19S27(1-& khcy;)S & iecy;27 & khcy;I3. The investigations were carried out using differential thermal analysis (DTA), X-ray diffraction (XRD) and electromotive force (EMF) measurements of concentration cells of the type (-) Bi (solid) / liquid electrolyte, Bi3+ / (Bi in alloy) (solid) (+) within the temperature range 300-370 K, with morpholine formate ionic liquid as the electrolyte. Based on the experimental data, a solid-phase equilibria diagram of the Bi2S3-Bi2Se3-BiI3 system was constructed, according to which it is characterized by the formation of a continuous series of solid solutions along the BiSI-BiSeI section and a wide homogeneity area based on Bi19S27I3. From the EMF measurement data, the partial thermodynamic functions of bismuth in solid solutions based on Bi19S27I3 were calculated. Using a fragment of the phase diagram of the quaternary Bi-S-Se-I system, the potential-forming reactions responsible for the indicated partial molar functions were determined and the standard thermodynamic functions of formation and standard entropies of the ternary compound Bi19S27I3 and the solid solutions Bi19S27(1-& khcy;)S & iecy;27 & khcy;I3 (x = 0.2, 0.4, 0.6) were calculated. In the calculations, in addition to the authors' own data, literature data on the corresponding thermodynamic functions of the BiSI compound, the solid solutions BiS1-& khcy;SexI and the S1-xSex alloys were used.
