Doklady Chemistry最新文献

Monoterpenes are a very interesting and important class of organic compounds that find wide practical application. In the presented work, we consider the most representative monoterpenes, show basic methods for preparing these compounds, describe their physicochemical properties, and outline the main areas of application of monoterpenes and their derivatives. In addition, the main representatives of monoterpenoids are considered, and the results of the authors’ own research carried out in this area using menthol and its functionalized derivatives as an example are shown.

Hydrazone derivatives have gained significant attention in medicinal chemistry as promising candidates to address critical therapeutic challenges, particularly antibiotic resistance. Their unique structural and electronic properties enable diverse biological interactions, positioning them as valuable scaffolds for drug development. In this work, we used computational approaches to evaluate the electronic and biological properties of 3-bromo-2-[(2Z)-2-(2-oxonaphthalen-1(2H)-ylidene) hydrazinyl] benzoic (BrOHBA). Quantum chemistry computations using the B3LYP/6-311++G(d,p) level of calculation elucidate details about the molecule’s reactivity, stability, and favorite sites for nucleophilic and electrophilic attacks. Natural bond orbitals (NBO) analysis revealed delocalization effects around the phenyl ring, which were connected to significant bioactivity. The nature of interactions within a molecule can be determined using reduced density gradient (RDG) analysis and interaction region indicator (IRI) topology analysis. Molecular docking simulations using AutoDock Vina demonstrated strong binding affinity against prolyl aminopeptidase (PAP) (PDB: 1QTR). The compound’s favourable ADMET profile further supports its drug development potential. These comprehensive computational insights position BrOHBA as a lead candidate, warranting experimental validation for infectious disease applications.

The antiradical, reducing, and iron-chelating activities of hydroxychalcone derivatives 1, 2, and 3 have been studied in comparison with the synthetic lipophilic analog of vitamin E—2,6-di-tert-butyl-4-methylphenol (ionol). Compound 3 demonstrated the highest efficacy in tests with DPPH^• and ABTS^•+ radicals, surpassing ionol by 1.3–2 times, which is presumably due to the presence of both chalcone and sterically hindered phenol moieties. In the reaction with the natural nitroxyl radical, the chalcones exhibited weaker antiradical activity than ionol. The reducing activity of the compounds in the CUPRAC and FRAP tests did not exceed the values of the reference compound, Trolox. Chalcone 3 with a sterically hindered phenolic moiety showed the highest Fe²⁺-chelating ability. The results confirm the potential of modified chalcones as multifunctional antioxidants for applications in the food and feed industries.

The present study concerns polymer composite materials based on polypropylene with biodegradable properties with additives of crude natural rubber and rubber tree seed oil both individually and in a mixture, which are designed to increase the biodegradation of compositions after use during the deposition process. Polypropylene (PP) produced by Omsk Polypropylene Plant LLC of the PP H 030GP 38/01-17 C30B brand was used as the object of the study. Natural rubber (NR-U) of the SMR-10 brand (Vietnam) and seed oil of the rubber tree (SIS) (Vietnam) are used as biodegradable additives. Organoleptic parameters—the smell and taste of water after the samples were soaked in it were evaluated according to SIS 22648-77. Plastics. Methods for determining hygiene indicators. The tendency of materials to water absorption was carried out according to SIS 4650-2014 ISO 62:2008. The exposure time is usually 24 h. But in this study, a water absorption test was conducted for 7 days. It was found that the introduction of destructive additives of crude natural rubber and rubber tree seed oil into polypropylene in concentrations above 15% by weight. for natural rubber and above 3% by weight. for rubber tree seed oil, as well as for mixtures of crude natural rubber with rubber tree seed oil, the studied concentration limits worsen the hygienic performance of compositions using them by one point. It will be possible to obtain more precise information about the possibility of using the studied compositions for the manufacture of products for various purposes when studying the composition of aqueous extracts. At the same time, the water absorption of composites using the studied additives is insignificant, no more than 0.8% by weight.

Protective groups are of great importance when choosing a strategy for the synthesis of organic substances. The multi-stage nature of syntheses of target organic molecules, various conditions, lability and reactivity of substrates, intermediate and target products, and individual functional groups of molecules force chemists to use a variety of protective groups to prevent decomposition of the desired substances, increase the regioselectivity of the synthesis processes, and eliminate the influence of aggressive reagents on labile reactive centers in the molecule. Along with this, the process of removing protective groups involves selecting conditions that reduce or eliminate undesirable side reactions. Among these methods is hydrogenation, one of the special cases of which is reductive debenzylation. This reaction of introducing and removing a benzyl group is one of the most common reactions in organic synthesis, since the relative ease of introduction and the chemical and thermal stability of the benzyl group and the possibility of its indirect introduction are the preferred factors for using this method by synthetic chemists. This reaction is used for the synthesis of a wide range of compounds, such as drugs, high-energy substances, and polymers [1–11]. Since the reaction is universal, many organic molecules can act as a substrate for this process. Removal of the benzyl group involves the use of various methods, depending primarily on the structure and properties of the original substrates. This review considers the methods of reductive and oxidative N- and O-debenzylation using catalysts of various types and addresses approaches to the removal of benzyl protection in different classes of organic substances, such as aromatic compounds, crown ethers, tetrazoles, triazoles, substituted hexoses, and isowurtzitanes.

The possibility of biotransformation of prochiral heptan-2-one and octan-2-one to enantiomerically pure (2S)-(+)-heptan-2-ol and (2S)-(+)-octan-2-ol using P. crispum cells has been studied, and conditions have been selected to synthesize (2S)-(+)-heptan-2-ol in a high yield of 99% with an enantiomeric excess of 98% ee within 24 h. Transformation of octan-2-one within 72 h gives the corresponding alcohol in 67% yield (74% ee). Conditions for bioreduction of octan-2-one in the presence of various exogenous reducing agents—ethanol (1–5%), isopropanol (1–5%), or glucose (equimolar amount)—have been optimized. The maximum yield and optical purity of (S)-(+)-octan-2-ol, 78% (93% ee), is achieved in 48 h in the presence of 3% ethanol. Reduction of octan-2-one in the presence of isopropanol (1–5%) or an equimolar amount of glucose leads to some increase in the yield and/or optical purity of (2S)-octan-2-ol in comparison with biotransformation in the absence of an exogenous reducing agent.

The study explores the discrete innovation details of anthracyclines when adsorbed on Na-ameghinite multilayer materials. Frontier molecular orbitals (FMOs) analysis was performed to estimate the most stable structure adsorbed on the surface of ameghinite material. The study involved dynamic simulation performance to describe the behavior of atomic mobility on the surface with temperature variation and energetic parameters evolved through 1000-ps (1-ns) simulation time. The adsorption behaviors of anthracyclines in both water and acetone molecules were investigated, providing insight into the interaction mechanisms at the molecular level. Through the application of various adsorption models, the study evaluates the impact of solvent polarity on the efficiency and specificity of anthracycline adsorption. Furthermore, molecular docking simulations were employed to elucidate the binding affinities and potential mechanisms of interaction between anthracyclines and human lung cancer protein (ID: 2P85). The findings reveal the strong binding affinity of doxorubicin (–8.4 kcal/mol) that interacts with several amino acids via conventional and carbon-hydrogen bonds.

Ethylene and vinyl acetate copolymers are widely used to produce materials for various purposes. These materials are flammable. To reduce their flammability and combustibility, fire retardants with different mechanisms of action are used. The paper presents a comparative study of the influence of various fire retardants (melamine phosphate, melamine polyphosphate, melamine borate, and melamine cyanurate) on the process of thermal-oxidative decomposition of ethylene vinyl acetate. The effect of these fire retardants on the heat resistance of the polymer material and the processes of destruction of ethylene vinyl acetate at different stages is described. It has been demonstrated that melamine-based fire retardants, as a rule, increase the heat resistance of the polymer material, shift the polymer degradation range toward higher temperatures, and reduce the weight loss. Among the fire retardants used, the best results in increasing the heat resistance of ethylene vinyl acetate have been achieved in the case of melamine polyphosphate. Melamine derivatives, when decomposed, form, together with the products of ethylene vinyl acetate destruction, refractory and highly condensed phases, which affect the process of gas evolution during the decomposition of polymeric materials, and are also responsible for the formation of foam coke with fragments of the polymer matrix, which has a barrier effect.

A comparative study of the dielectric properties of the interpenetrating polymer network (IPN) of graphene (Gr) and poly(α-methyl styrene) (PAMS) was carried out using complex permittivity and permeability characterization. IPN was prepared under an inert atmosphere of nitrogen with varying molar concentrations. The synthesized polymer network was characterized using Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopic (FESEM) techniques, conductivity and complex permittivity and permeability characterization. The IPN was analyzed by FTIR spectroscopy, which depicts the presence of Gr at 1156, 1237, 1597, and 3439 cm^–1 and the presence of PAMS at 3056, 1494, 2932, and 696 cm^–1. These results indicate a proper chemical reaction and interpenetration among Gr and PAMS has occurred. The polymeric interconnected film is seen via the FESEM technique, which reveals heterogeneous and dual phase morphology. The conductivity of the polymeric network was found to be 1.2124 × 10^–6 Ω^–1 m^–1, revealing the semi-conductive behavior of the IPN. Permittivity data revealed enhanced dielectric property and better storage capacity. Moreover, permeability data shows that IPN possesses a moderate magnetism property too. By controlling factors like graphene concentration, orientation, and interfacial interactions within the polymer matrix, it’s possible to tune the dielectric properties of the composite material. This tunability allows for customizing the material for specific applications, such as energy storage devices. The morphology of an IPN consisting of Gr and PAMS would depend on various factors, including the preparation method, concentration of Gr and the interactions between the polymer and Gr.

Ordered self-organized lyotropic liquid crystals (LLCs) are widely used in biomedicine due to their ability to encapsulate chemically diverse biomaterials, i.e., hydrophobic or hydrophilic substrates. The creation of LLC complexes with carbon or quantum dots can yield systems with combined functions. Carbon dots (CDs), which are semiconductor nanomaterials, have unique luminescent properties and can be embedded into lyotropic mesophases (lyomesophases) to create hybrid systems and provide their use in biosensing, medical imaging, and theranostics. Importantly, wettability, adhesive interaction, friction, and permeability are in the main focus among the basic physicochemical surface characteristics of a polymer-based material. The wetting ability of a hybrid system is known to be determined by surface tension, which is very important for its interaction with the environment, e.g., with the surfaces of capillaries, tissues of blood vessel walls, skin, polymer tubes, and surface coatings of medical equipment elements. This paper describes the results of wetting of model hydrophobic and hydrophilic surfaces (glass, nylon, polydimethylsiloxane (PDMS), and polytetrafluoroethylene (PTFE)) with CD-doped gels and lyomesophases. Low-viscosity gels wetted these surfaces better than more viscous liquid crystal phases did, and the adhesion of a hybrid CD-doped sample had the same order of magnitude in contact either with glass or with a membrane for similar oligoethylene oxide-based lyomesophases. The adhesive characteristics of LLCs and gel-like systems prepared in the study may appear useful in the development of drug delivery methods for diagnostic and therapeutic nanosystems with improved functionality.