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Neuromodulatory properties of two aza analogues of amantadine - 6-amino-5,7-dimethyl-1,3 -diazaadamantane 3 and 7-amino-1,3,5-triazaadamantane 4, as well as a synthetic precursor of compound 3 - 5,7-dimethyl-1,3-diazaadamantan-6-one 2, - were investigated in experiments on outbred male mice. Azaadamantanes and the reference drug amantadine hydrochloride 1 were administered intraperitoneally in an aqueous solution at a dose of 20 mg/kg. Control animals were administered water. In a model of neuroleptic haloperidol-induced parkinsonism, it has been shown that 2 and 4 are more potent agents in dopamine-stimulating activity than amantadine. In the model of arecoline tremor, azaadamontanes 3 and 4 were found to have higher M-cholinergic blocking activity than amantadine. All azaadamantanes have been shown to potentiate adrenergic neurotransmission but do not have GABAergic activity. The most promising agent is triazaadamantane 4, which has demonstrated pronounced dopamine-stimulating and M-cholinergic blocking properties with moderate adrenergic activity.

Conjugates of drugs and biologically active compounds with stable nitroxides are often used to study pharmacokinetics, the biochemical mechanisms of activity and distribution of the active substance in body tissues using electron paramagnetic resonance and magnetic resonance imaging. In this work, we synthesised a paramagnetic analogue of ibuprofen, a known cyclooxygenase inhibitor, retaining the free carboxyl group for critical interaction with the active site of this enzyme. For this purpose, ibuprofen was subjected to nitration into the aromatic ring, the nitro group was reduced, and the resulting amine was acylated with 2,2,5,5-tetramethyl-3-pyrroline-1-oxyl-4-carboxylic acid chloride.

A novel predictive model based on meta-learning algorithms for estimating the energy gap between the frontier molecular orbitals of aromatic p-conjugated molecules is presented. The main goal of the study was to develop a highly accurate and robust model capable of replacing computationally expensive quantum chemistry calculations, in particular the methods based on density functional theory, for screening organic compounds in optoelectronic applications. The filtered subset of the publicly available PubChemQC PM6 database was used as the primary dataset. Molecular structure was encoded using Morgan fingerprints, which served as input for training three base models: Random Forest, Gradient Boosted Trees, and a fully connected Neural Network. Among these, the Gradient Boosted Trees model achieved the best performance (the mean absolute error was 0.1795 eV). To improve prediction accuracy, a meta-model was implemented and trained on the outputs of the above-mentioned base models. This approach demonstrated improved accuracy: the final mean absolute error was 0.1744 eV, which is 8 % better than simple averaging and 3 % better than the best-performing individual model. The proposed approach can be further enhanced by expanding the dataset and incorporating additional models, which pave the way for more accurate and efficient prediction of the properties of organic conjugated molecules in optoelectronics.

2,7-Di(thiophen-2-yl)-9H-(4,5-diazafluoren)-9-one (TDAFO) was synthesised and its crystal structure, optical and electrochemical properties were studied. The target compound was obtained using the Stille reaction from 2-(tri(n-butylstannyl)thiophene and 2,7-dibromo-4,5-diazafluoren-9-one. Using X-ray diffraction analysis, the crystal structure of TDAFO was solved, and the formation of weak π-stacking interactions, C-H…N and C-H…O hydrogen bonds was revealed. The oxidation and reduction potentials of TDAFO were evaluated by cyclic voltammetry, and the possibility of TDAFO electropolymerisation on conductive coatings was demonstrated. The optical properties of both the monomer and the polymer obtained by electrochemical polymerisation were studied. The photoluminescence quantum yield of TDAFO was determined to be 7 % in solution and 13 % in the crystalline form.

Рiperidine nitroxides have found many applications in various fields of science and technology. The introduction of bulky alkyl substituents in an adjacent position to the N-O fragment imparts useful characteristics to such radicals, increasing their stability in biological samples, enhancing their protective antioxidant properties and making them valuable regulators of radical polymerisation. A sterically hindered nitroxide with a spiro-2-hydroxymethylcyclopentane moiety and two ethyl groups at positions 2 and 6 of the piperidine ring, respectively, was synthesised. For this purpose, the condensation of 2-(2-aminoethyl)-2-methyl-1,3-dioxolane with diethyl ketone under the conditions of acid catalysis was carried out. The resulting spirocyclic piperidine was oxidised to aldonitrone. Spiro-2-hydroxymethylcyclopentane moiety was assembled via the reaction with 4-pentenylmagnesium bromide, followed by oxidation and intramolecular 1,3-dipolar cycloaddition and reductive opening of the isoxazolidine ring. The resulting dispirocyclic piperidine was oxidised to the corresponding nitroxide, 8-[(hydroxy)methyl]-13,13-diethyl-1,4-dioxa-12-azadispiro[4.1.4.3]tetradecane-12-oxyl. The kinetics of reduction of the latter by ascorbic acid has been studied.

Structural modification of the Finland-type trityl core by replacing carboxyl groups by alkoxymethyl substituents (CH₂OCH₂CO₂H) resulted in new triarylmethyl radicals, which showed extremely high stability in the presence of superoxide.

The work is concerned with the synthesis of biologically active substances based on monoterpenoids through their chemical modification to increase the pharmacological potential of the synthesised compounds. The starting substances to synthesise urea derivatives were adamant-1-ylisocyanate and monoterpenoid amines with a perillyl or myrtenol fragment. These monoterpenoid substituents were chosen on the basis of literature data suggesting that the indicated compounds exhibit activity with respect to the nervous system in various animal models. On the basis of these ureas, imidazoline-2,4,5-triones were synthesised. These urea derivatives potentially possess lower lipophilic properties.

The structure of asphaltenes of oils sampled in various oil and gas provinces and differing from each other in chemical types and contents of asphaltene components has been studied using an oxidation reaction catalysed by ruthenium ions. Structural fragments, covalently bound through C_ar-C links with the aromatic rings of their molecules, and the compounds occluded in the hollow cells of macromolecular structures in asphaltenes are shown to be present in all the samples under investigation. The covalently bound fragments are represented by normal and branched alkanes, cheilanthanes, gopanes, and aromatic structures of the biphenyl type. Typical biological markers, n-alkanes and hopanes, have been identified among occluded compounds. n-Alkylbenzenes, n-alkyltoluenes, n-alkylxylenes, n-alkyltrimethylbenzenes, and alkylbenzothiophenes are additionally found in the composition of non-oxidised naphthenic aromatic oil compounds.

Two- and three-component systems of deep eutectic solvents (DES) based on polyatomic alcohol - pentaerythritol (PER), carbonic acid diamide - urea (carbamide, CA) and quaternary ammonium salt - choline chloride (CC) were synthesised: PER-CC, PER-CA, CC-CA, PER-CA-CC. Eutectic points in the obtained DES systems were determined. It is shown that the lowest melting point (-14.5 °C) is observed for the three-component DES system based on PER-CA-CC with the molar component ratio of 1.3 : 2.4 : 1, respectively. The solubility of this three-component system was determined by dissolution in water prior to precipitation. The density of the aqueous solutions of binary DES systems was determined to be within the range of 1.2158-1.2458 g/cm³. The presence of hydrogen bonds in binary and ternary DES systems was revealed by IR spectroscopy: CC acts as an acceptor of hydrogen bonds, while PER and CA act as donors. The presence of hydrogen bonds between DES components provides the formation of stable molecular complexes and lowering of the melting/crystallisation points of DES compositions due to intermolecular bond weakening and destruction of the crystal structures of initial substances.

Extrusion-based 3D printing methods are widely used to fabricate tissue-engineered constructs for regenerative medicine with specific dimensions, shapes, and properties tailored to the nature of the wound defect. High-viscosity solutions of the anionic polysaccharide sodium alginate show a potential as a base material for developing hydrogel inks for 3D printing. However, printing with sodium alginate solutions presents technical challenges due to the need for rapid gelation immediately after extrusion to form an elastic gel. This study demonstrates the possibility of controlling the viscosity of sodium alginate solutions by introducing a gelation modifier - ferulic acid, which participates in the formation of an entanglement network. Using IR spectroscopy, the nature of interactions in alginate-based materials obtained in the presence of ferulic acid was investigated. The conditions for producing highly hydrated gel structures based on an ionogenic polysaccharide solution and ferulic acid were optimised using piston-based 3D printing.