This scientific work presents practical and theoretical material on the methods of analysis and identification of betulin and its key derivatives. The properties of betulin and its derivatives, which are determined by the structural features of this class of compounds and their tendency to form dimers, polymorphism and isomerization, are considered. This article outlines ways to improve not only the bioavailability but also the solubility of triterpenoids, as well as any hydrophobic drug substances, through chemical transformations by introducing various functional groups, such as carboxyl, hydroxyl, amino, phosphate/phosphonate and carbonyl. The authors of this article summarized the physicochemical characteristics of betulin and its compounds, systematized the literature data on IR and NMR spectroscopy and gave the melting temperatures of key acids and aldehydes based on betulin.
The interaction results of 1,2-dibromo-3-isothiocyanatopropane with some pyrazoles as well as cytisine and salsoline alkaloids were presented in this paper. It was shown that the reaction resulted in one one-step and rather mild method for the preparation of the corresponding 1,3-thiazoline bromomethyl derivatives. The yield of this reaction was affected by the presence of a base and an order in which reagents were added. Molecular docking of the synthesized 1,3-thiazoline derivatives for putative antibacterial activity was carried out using the penicillin-binding target protein (PBP4) of the bacteria E. coli “Homo sapiens” and S. aureus “Homo sapiens” as an example. Molecular docking demonstrated that the compounds had insignificant binding energies at the level of selected reference drugs (Cephalotin and Chloramphenicol). The presence of natural alkaloids in the structure of thiazoline derivatives somewhat increased the affinity of these substrates for target proteins selected.
The increasing depletion of high-grade nickel sulfide deposits and the growing demand for nickel have intensified global interest in oxidized nickel ores (ONOs), particularly those located in Kazakhstan. This study presents a comprehensive review of the mineralogical and chemical characteristics of ONOs from the Shevchenkovskoye cobalt–nickel ore deposit and other Kazakhstan deposits, highlighting the challenges they pose for conventional beneficiation and metallurgical processing. Current industrial practices are analyzed, including pyrometallurgical, hydrometallurgical, and pyro-hydrometallurgical methods, with an emphasis on their efficiency, environmental impact, and economic feasibility. Special attention is given to the potential of hydro-catalytic leaching as a flexible, energy-efficient alternative for treating low-grade ONOs under atmospheric conditions. The results underscore the necessity of developing cost-effective and sustainable technologies tailored to the unique composition of Kazakhstani ONOs, particularly those rich in iron and magnesium. This work provides a strategic framework for future research and the industrial application of advanced leaching techniques to unlock the full potential of Kazakhstan’s nickel resources.
1 June 2013 in Russian Journal of General Chemistry
New derivatives of cytisine and anabasine alkaloids containing benzothiazole and benzimidazole fragments were discussed. Physicochemical characteristics of the new compounds were determined. The structure of 1-(cytisin-1-yl-methyl)benzimidazole-2-thione was studied by X-ray diffraction analysis.
Air pollution issues are relevant all over the world, especially in industrial areas. The main pollution of the atmosphere is caused by dust emissions from industry. This article discusses the issue of dust emission from the coal industry. The purpose of this research is a comprehensive analysis and environmental assessment of the impact of coal storage processes on the environment. The study was conducted on the example of a coal deposit in the Karaganda region of the Republic of Kazakhstan. The Karaganda region is the industrial base of Kazakhstan, and is characterized more by coal industry facilities. In addition to the impact during the mining period, coal storage is also a serious problem. The problem of storing energy coals on a large scale of their extraction and consumption has a huge impact on the environment, but it is of great economic importance for the region. In this paper, practical methods of combating weathering are considered using the example of coal: small fraction—0–50 mm; large fraction—50–300 mm; oversized—more than 300 mm. Calculations of the formation of emissions, the maximum surface concentrations of pollutants from coal depots were carried out, and plots of their dispersion were constructed. When plotting the dispersion of pollutants, it was revealed that the largest concentration of substances falls on the territory of the coal deposit. According to the data obtained, a directly proportional dependence of the amount of emissions on the volume of incoming coal and the area of the base of the coal stacks is obvious; the temperature fluctuation in the stacks during the research is in the range from 21.9 to 26.1 °C. Scientifically researched anti-emission cover (AEC) on coal stacks. AEC has advantages for a specific climate (frequent winds, dryness): preservation of properties up to 90% over their service life; resistant to environmental aggressiveness and mechanical influences. This method solves two tasks: the first task is to prevent spontaneous combustion of coal stacks, and the second task is to reduce dust emissions from coal stacks. Measures have been developed to minimize the negative impact of coal stacks on the environment.