The relevance of studying the regulation of protein-ligand interactions is due to the emergence of new views on the role of metabolites and their key importance in vital processes. To study the protein-ligand interaction, the AB0 antigen-antibody blood system and the enzyme-substrate system of dehydrogenases were used as a test system, and ethanol was used as an influencing factor. In experiments performed with A and B blood erythrocyte antigens, natural AB0 system antibodies and monoclonal antibodies under the influence of ethanol performed change of the degree of agglutination and the time to onset of erythrocyte agglutination. It was found that ethanol can regulate the enzyme-substrate interactions of dehydrogenases: lactate dehydrogenase (EC 1.1.1.27), glyceraldehyde phosphate dehydrogenase (EC 1.1.1.12), and α-glycerol phosphate dehydrogenase (EC 1.1.1.8). The increase in the activity of studied enzymes under the influence of ethanol in the whole blood hemolysate was 2.5 - 3 times higher than in the isolated medium (with pure enzyme preparations).

We investigate a well-known phenomenon of the appearance of the crossover points, corresponding to the intersections of the solubility isotherms of the solid compound in supercritical fluid. Opposed to the accepted understanding of the existence of two fixed crossover points, which confine the region of the inverse isobaric temperature dependence of the solubility, we have found that these points tend to shift with the change of the temperature and in the limit of the certain threshold value they converge to a single point. We demonstrate this analyzing the solubility data of a set of poorly soluble drug compounds, which have been computed in a wide area of the phase diagram via the approach, based on the classical density functional theory. Thorough analysis of the available in the literature experimental solubility data is found to be in an agreement with our conclusions, as one can find that the wider temperature region of the experimental study is, the more pronounced effect of the crossover points drift can be observed.

Tertiary amines represent a key class of organic molecules with multiple industrial, synthetic, and analytical applications. The focus of this review is on different approaches towards the synthesis of the C3 and C3V symmetrical tertiary amines. Generally, symmetrical tertiary amines can be prepared via N‐alkylation with alkyl halides and alcohols, reductive amination, desamination, hydroamination of olefins, and different kinds of C–N cross‐coupling reactions. All reactions leading to the titled structures are discussed, and the advantages and disadvantages of each method are provided.

We develop a new quantitative molecular theory of liquid-phase dipolar polymer gels. We model monomer units of the polymer network as a couple of charged sites separated by a fluctuating distance. For the first time, within the random phase approximation, we have obtained an analytical expression for the electrostatic free energy of the dipolar gel. Depending on the coupling parameter of dipole–dipole interactions and the ratio of the dipole length to the subchain Kuhn length, we describe the gel collapse induced by electrostatic interactions in the good solvent regime as a first-order phase transition. This transition can be realized at reasonable physical parameters of the system (temperature, solvent dielectric constant, and dipole moment of monomer units). The obtained results could be potentially used in modern applications of stimuliresponsive polymer gels and microgels, such as drug delivery, nanoreactors, molecular uptake, coatings, superabsorbents, etc.

New hybrid N-acetonylpyridinium, N-(ω-iodoacetonyl)pyridinium, and N-acetonyl-2,6-dimethylpyridinium halobismuthates I–VII have been synthesized and structurally characterized. A preparative method of synthesis is proposed for compounds I, III, and VII, and some individual crystals have been managed to separate and characterize for compounds II, I–VI. A new type of {K[BiBr6]}n2n- 1D-chains with K+ cations has been revealed in the structure of [C8H10NO]2K[BiBr6] (II). N-acetonyl-2,6-dimethylpyridinium bromobismuthates [C10H14NO]3[Bi2Br9] V and VI (space group P21/n) are polymorphs of similar structure. Iodobismuthates [C8H10NO]4[Bi4I16] (III) and [C10H14NO]4[Bi4I16] ⋅ 0.69I2 (VII) are built of [Bi4I16]4– anions, and [Bi4I16] moieties in the structure of VII are linked into a 1D-anionic chain by molecules I2.

The crystal structure of the new iodobismuthate (PyPy)2(PyPyH)2Bi6I26 was found to consist of unusual hexanuclear [Bi6I26]6– anions containing the linear I4 2– unit, and the experimental Bi–I bond lengths in this anion were used to obtain the relationship between bond length and bond energy. A statistical analysis of 229 crystal structures of iodobismuthates, based on the quantum chemically estimated strength of Bi–I bonds, revealed that the total energy of the Bi3+ polyhedron remains virtually constant at 64 ± 2 kcal mol–1, regardless of its geometry within this family of materials. Thus, the polyhedron geometry flexibly adapts to the relatively weak interactions between iodobismuthate anions and embedded cations.

New methylviologen (MV2+) bromobismuthate [MV]3[BiBr6]2 · 2H2O (I) isostructural to the well-known chlorobismuthate [MV]3[BiCl6]2 · 2H2O has been prepared from an aqueous solution and cha-racterized by X-ray diffraction. The reaction between I and concentrated HBr leads to the formation of acidic methylviologen bromobismuthate-bromide [H3O]2[MV][BiBr6]Br · 4H2O (II) and a minor impurity of bromobismuthate tribromide [MV]3[Bi2Br9][Br3]3 (III). The acidic bromobismuthate of ethylviologen (EtV2+) [H3O][EtV][BiBr6] · 1.34H2O (IV) formed under similar conditions has another composition. Thermal decomposition of II yields single-phase [MV][BiBr5], which has a low optical band gap. The electrochemical characteristics of I and related iodobismuthate [MV]3[Bi2I11]I have been compared.

Recent progress in observational astronomy and astrophysics has stimulated the intensive laboratory studies aimed at elucidation of the mechanisms of evolution of molecular matter in interstellar space and various space objects. One of the most intriguing and rapidly developing areas of these studies is the so-called "cold astrochemistry" devoted to the complex processes occurring in astrophysical ices. In this context, the matrix isolation technique (known for decades) is a very useful approach for both interpretings the results of astrophysical observations and verifying possible mechanisms of key astrochemical processes. This review outlines the most important results of recent studies using matrix isolation technique, which contribute to the solution of the problems of "cold astrochemistry" in two main aspects: (i) spectroscopy of astrochemical important molecules, ions and radicals stabilized in cryogenic matrices; (ii) experimental modeling of mechanisms of radiation-induced and "in dark" chemical reactions occurring in "cold" space environments (interstellar, cometary and planetary ices). In the first aspect, special attention is paid to new spectroscopic data obtained using various methods (electronic and vibrational absorption spectroscopy, electronic paramagnetic resonance spectroscopy). In the second aspect, we consider the chemical effects resulting from both direct excitation of isolated molecules and the transfer of energy initially absorbed by the medium. Special attention is paid to recent studies of spectroscopic characteristics and radiation-induced evolution of matrix-isolated weak intermolecular complexes, which can be considered as "building blocks" for the cold synthesis of complex molecules in the absence of diffusion mobility. In addition, we consider the use of matrix isolation for the studies of low-temperature chemical reactions "in dark" involving atoms and highly reactive intermediates, which can occur in cold space environments. In the final part, we briefly discuss the applicability of the results of matrix isolation experiments for interpretation of the mechanisms in molecular ices and highlight the prospects of this field. The review can also be useful for the specialists in various aspects of chemistry and chemical physics (radiation chemistry, photochemistry, molecular spectroscopy, low-temperature chemistry). The bibliography includes 379 references.

The unusual framework of the middle C-ring, “broken” as a result of biotransformations and oxidations in vivo and bearing an sp3-C connection, is of interest for biosynthetic investigations. The reported 39 natural compounds (55 including stereoisomers) have been analyzed and arranged into three structural groups. The biosynthetic origin of all these compounds has been thoroughly reviewed and revised, based on the found connections with oxidized angucyclinone structures. The data on biological activities has been summarized. Careful consideration of the origin of the structure allowed us to outline a hypothesis on the biological function as well as prospective applications of such atypical angucyclinones.

2-Dialkylamino-arylidene-imidazolones undergo intermolecular tandem [1,5]-hydride shift and cyclization to form spirocyclic tetrahydroquinoline derivatives under TiCl4 promotion. Different substitutions on each of the aryl, amino and imidazole fragments are tolerated, which results in 20+ examples and 25–95% yields.