Search

Conformational analysis of tris(4-methylphenyl)phosphine and its oxide, sulfide, and selenide has been performed by the dipole moment method and DFT quantum chemical calculations at the B3PW91/ 6-311++G(df,p) level of theory. The title compounds have been found to exist in solution as a single symmetrical conformer with gauche,gauche,gauche orientation of the substituents on the phosphorus atom with respect to the P=X bond (X = LEP, O, S, Se).

DFT quantum chemical calculations at the B3PW91/6-31G(d) level of theory have shown that the addition of secondary phosphine sulfides and phosphine selenides with alkyl, phenyl, and phenylalkyl substituents to pentyl vinyl and hexyl vinyl selenides follows a molecular mechanism against the Markovnikov rule through energetically favorable eight-membered transition state, leading to the formation of tertiary phosphine chalcogenides. Secondary phosphine selenides are more reactive than the corresponding phosphine sulfides.

Aim. To analyze the expression of key apoptosis (Bcl-2, caspase-3) and autophagy (Beclin 1, Vps34, p62 and LC3) proteins regulators in peripheral blood T-lymphocytes of patients with systemic lupus erythematosus. Methods. The object of the study was peripheral blood T-lymphocytes of healthy donors and patients with systemic lupus erythematosus. To obtain T cells, we used the immunomagnetic separation method. Protein expression was analyzed using the Western blot method. Statistically analyzing the results was performed using the R software environment. The data was represented using boxplots. Groups were compared using the MannWhitney test. Results. According to the results of the study of the apoptotic proteins, we found an increased content of caspase-3 and the absence of significant changes in the content of the anti-apoptotic protein Bcl-2 in patients with lupus, which indicates active apoptotic activity. A comparative analysis of Beclin 1 and Vps34 showed their increased content in the cells of patients, which indicates the activation of autophagy. The analysis of two isoforms of LC3 protein revealed their low content in the group of patients. Since the scatter of indicators was very different from the average value, we analyzed these indicators depending on the severity of the disease. In the acute course group, high content of protein LC3-I was detected, the content of form II was lower. In the group with the subacute course, the number of both isoforms is lower than in the other groups. In the group with a chronic course, significant increases of protein LC3-II and a decrease in the ratio of LC3-I/LC3-II were found. Conclusion. The study showed that depending on the severity of systemic lupus erythematosus, the content of protein LC3 isoforms changes, which can be used for differential diagnosis of disease forms.

Conformational analysis of Se-esters of diselenophosphinic acids has been performed and their polarities have been determined using the methods of dipole moments and quantum chemistry (DFT [B3PW91/6-311++G(df,p)]+CPCM). In solution, the studied compounds exist as an equilibrium of several conformers with staggered gauche and trans- or eclipsed cis-orientation of the substituents relative to the P=Se bond. The presence of eclipsed cis-conformations is explained by the formation of intramolecular H⋯Se bonds involving the hydrogen atom of the Se-alkyl(benzyl) or phenyl substituents at the phosphorus atom and the selenium atom of the P=Se group.

According to DFT calculations, hydrolysis of 1,1,1-trisubstituted hyposilatranes and hypogermatranes proceed in one stage and have lower activation energies than hydrolysis of the corresponding atranes and ocanes, and, unlike what is observed with the tricyclic and bicyclic analogs, the former reactions are characterized by positive Gibbs energies. The configuration of the hydrolysis products is stabilized by the transannular interactions N→X and O→X (X = Si, Ge) and intramolecular hydrogen bonding.

Conformational analysis of tris(3-methylphenyl)phosphine and its chalcogenides has been performed by methods of dipole moments, IR spectroscopy, and quantum chemistry [DFT B3PW91/6-31G(df,p)]. In solution, these compounds exist as an equilibrium of conformers with gauche- and cis-arrangement of the substituents at the phosphorus atom relative to the P=X bond (X = lone electron pair, O, S, Se).

According to DFT quantum chemical calculations, hydrolysis of 2,2-disubstituted silocanes and germocanes is characterized by lower energies of activation and slightly lower positive Gibbs energies than the hydrolysis of the corresponding silatranes and germatranes. The annular configuration of the hydrolysis products is stabilized by the transannular interaction N→X (X = Si, Ge) and intramolecular hydrogen bonding.

The article researches specifics of temporal and cultural markers of Russian work of literature ‘A Country Doctor's Notebook’ by M.A. Bulgakov and its’ English translation. Elicited lexical units fall into thematic groups: person, artifact, actions, diseases and place. The part-of-speech classification followed and revealed prevailing nouns. Further stage involved the study of immediate context of the units., В статье рассматривается специфика темпоральной и культурной маркированности лексики в русскоязычных художественных произведениях и их передачи при переводе на английский язык. В частности изучается произведение «Записки юного врача» М.А. Булгакова. Рассматриваемые единицы составляют ряд тематических групп: лицо, артефакт, действия, болезни и место. Частеречная классификация выявила преобладание однословных существительных. Далее был изучен ближайший лексикосинтаксический контекст исследуемого материала.