Asymmetric synthesis of Cyclic β-Amino Carbonyl Derivatives by a Formal [3+2] Photocycloaddition

Herein, a visible-light mediated strategy unlocking a family of cyclic β-amino carbonyl derivatives bearing three contiguous stereogenic centres is introduced. The overall reactivity relies on the performance of the substrate-catalyst...

Protective Effect of Dinitrosyl Iron Complexes Bound with Hemoglobin on Oxidative Modification by Peroxynitrite

Dinitrosyl iron complexes (DNICs) are a physiological form of nitric oxide (•NO) in an organism. They are able not only to deposit and transport •NO, but are also to act as antioxidant and antiradical agents. However, the mechanics of hemoglobin-bound DNICs (Hb-DNICs) protecting Hb against peroxynitrite-caused, mediated oxidative modification have not yet been scrutinized. Through EPR spectroscopy we show that Hb-DNICs are destroyed under the peroxynitrite action in a dose-dependent manner. At the same time, DNICs inhibit the oxidation of tryptophan and tyrosine residues and formation of carbonyl derivatives. They also prevent the formation of covalent crosslinks between Hb subunits and degradation of a heme group. These effects can arise from the oxoferryl heme form being reduced, and they can be connected with the ability of DNICs to directly intercept peroxynitrite and free radicals, which emerge due to its homolysis. These data show that DNICs may ensure protection from myocardial ischemia.

Effects of Structural Substituents on the Electrochemical Decomposition of Carbonyl Derivatives and Formation of the Solid–Electrolyte Interphase in Lithium-Ion Batteries

The solid–electrolyte interphase (SEI), the passivation layer formed on anode particles during the initial cycles, affects the performance of lithium-ion batteries (LIBs) in terms of capacity, power output, and cycle life. SEI features are dependent on the electrolyte content, as this complex layer originates from electrolyte decomposition products. Despite a variety of studies devoted to understanding SEI formation, the complexity of this process has caused uncertainty in its chemistry. In order to clarify the role of the substituted functional groups of the SEI-forming compounds in their efficiency and the features of the resulting interphase, the performance of six different carbonyl-based molecules has been investigated by computational modeling and electrochemical experiments with a comparative approach. The performance of the electrolytes and stability of the generated SEI are evaluated in both half-cell and full-cell configurations. Added to the room-temperature studies, the cyclability of the NMC/graphite cells is assessed at elevated temperatures as an intensified aging condition. The results show that structural adjustments within the SEI-forming molecule can ameliorate the cyclability of the electrolyte, leading to a higher capacity retention of the LIB cell, where cinnamoyl chloride is introduced as a novel and more sustainable SEI forming agent with the potential of improving the LIB capacity retention.

The influence of metals of variable valence on the oxidative modification of albumin amino acid residues

BACKGROUND: The constancy of the protein composition of the body is one of the most important conditions for normal vital activity. Deviations in the content of the main bioelements, in particular, mixed valence metals, caused by environmental factors, improper nutrition and other factors, lead to various disorders. One of the properties of metals of mixed valence is the abil-ity to cause metal-catalyzed oxidation of proteins in joint action with active forms of oxygen. It seems interesting to study the oxidative modification of the amino acid residues of albumin and the change in its properties. AIM: To study the effect of reactive oxygen intermediates generated by the Fenton reaction in the presence of Fe2+ and Cu2+ on the oxidative modification of amino acid residues of bovine serum albumin. MATERIALS AND METHODS: The study was carried out on bovine serum albumin (BSA), which was incubated for 2 hours in a mixture of Fenton's reagents – FeSO4 + H2O2 and in a mixture of СuSO4 + H2O2. The quantitative protein content in the samples was determined with the bromcresol green reagent (Albumin-Olvex). The content of carbonyl derivatives of proteins was estimated by the method of R.L. Levine modified by E.E. Dubinina. The content of thiol groups in albumin samples from the control and experimental groups was determined by the Ellman method with DTNB (under non-denaturing conditions. RESULTS: The presented results demonstrate that under the action of Cu2+ ions, the formation of carbonyl derivatives of aliphatic amino acids of albumin is less than in the presence of Fe2+, which can be explained by the different degrees of albumin affinity to metals of variable valence. The rate of mobility of oxidatively modified albumin in polyacrylamide gel decreases, which is explained by protein aggregation due to bityrosine cross-links. CONCLUSION: Variable valence metals affect the modification of albumin. The change in the functional properties of the protein is of physiological significance, including the case of extracellular mobilization of iron and copper.

Assessment of the influence of pesticides based on glyphosate on the health of agricultural producers

Introduction. The results of a hygienic risk assessment of the use of pesticides based on glyphosate in agricultural production are presented. The study of the pathogenetic mechanisms of action on the body of widely used glyphosate-containing herbicides and the search for markers of health conditions that change under the influence of these drugs are of increasing interest for the early diagnosis of pathological processes and the prevention of occupational and occupational diseases. The aim of this study was to assess the health effects of glyphosate-based pesticides on the health of operators in an agricultural environment. Materials and methods. The clinical material for the study was the plasma and erythrocytes of the peripheral blood of operators in contact with glyphosate-containing pesticides. As a control group, 20 clinically healthy individuals of the same age group, who had no contact with the studied pesticides, were selected. There were assessed leading indices of general clinical and biochemical blood tests and markers of endogenous intoxication and oxidative stress. Results. There were established acceptable risk of exposure to pesticides on workers, subject to compliance with technological regulations and safety requirements. Minor deviations of indicators of general and biochemical blood tests were revealed. A statistically significant increase in the total level of carbonyl derivatives compared to control was obtained among operators who had more substantial contact with glyphosate-containing pesticides. Conclusion. Working conditions when using preparations in the form of aqueous solutions containing glyphosate, using ground-based spraying of steam fields with a consumption rate of 8 l / ha, subject to compliance with regulations and safety measures, comply with hygienic requirements. The established statistically significant changes in the blood parameters of the operators in comparison with the control group indicate the presence of a risk to the health for workers in contact with glyphosate-containing pesticides and indicates the need for additional biochemical studies during periodic medical examinations of agricultural workers for the early detection of deviations in the health state caused by exposure to pesticides, including those containing glyphosate.

STUDY OF THE BIOLOGICAL PROPERTIES OF SEMI- AND THIOSEMICARBAZONES OF CARBONYL DERIVATIVES OF 4-BUTANOLIDES

Based on carbonyl derivatives of 4-substituted-4-butanolides, the appropriate semi- and thiosemicarbazones have been synthesized. It has been found that some representatives of thiosemicarbazones have pronounced algicidal activity against filamentous green alga Cladophora and blue-green alga (cyanobacterium) Synechocystis and some of the semi- and thiosemicarbazones exhibit moderate antitumor activity. The assessment of the antitumor activity of the compounds was carried out using strains of syngeneic and allogeneic tumor systems as test-objects: lymphocytic leukemia P-388, Lewis lung carcinoma, B16 melanoma and Ehrlich’s ascites tumor. It has also been established that some representatives of thiosemi­carbazones exhibit antimutagenic properties. It has been reliably proven that with the formation of a thiazole ring, all properties disappear and a new property in the series of thiazololactones is revealed – antibacterial․

Thiophene-3-carbonyl Chloride

The X-ray structure of the title compound has been determined for the first time. It shows the ring flip disorder common among thiophene-3-carbonyl derivatives and the occurrence of this phenomenon in the structures of such compounds is discussed.