Synthesis, quantum-chemical calculations and virtual screening of the alkaloid cytisine derivatives

The synthesis of some cytisine derivatives was carried out in the work. The article provides the data of quantum-chemical calculation and virtual screening of the alkaloid cytisine derivatives synthesized. At the same time, the reaction centers of the cytisine derivatives molecules were determined. In order to study the reactivity of the derivatives obtained (namely cinnamoylcytisine, lipoylcytisine, and cytisinylisoalantholactone) the quantum-chemical calculations were conducted to determine the energy and charge characteristics of the molecules. The results indicate a sufficient thermodynamic stability of the cinnamoylcytisine and lipoylcytisine molecules. The cytisinylisoalantholactone molecule is not stable according to the results of quantum chemical calculations. The data on the energy values of the frontier molecular orbitals show that, in general, all molecules exhibit electrophilic properties. A bioprediction was implemented using PASS (Prediction of Activity Spectra for Substances) as one of the most efficient and well-known computer program with the aim of detailed study and the probable establishment of the biological activity of the synthesized cytisine derivatives. Based on the results of virtual screening, promising types of alkaloid cytisine derivatives were identified, which are potential sources of original drugs

CYCLODEXTRIN INCLUSION COMPLEXES OF PHARMACEUTICALLY ACTIVE DERIVATIVES OF THE CYTISINE ALKALOID AND THEIR HEMORHEOLOGICAL ACTIVITY

The alkaloid cytisine is of great importance for modern pharmacological studies. This alkaloid can be used as a component of the supramolecular system with cyclic oligosaccharides, namely β-cyclodextrins, which have a truncated cone-shaped molecule with internal protons Н3 and Н5 and external ones Н2 and Н4. The aim of the work is to obtain inclusion complexes of pharmaceutically active derivatives of the alkaloid cytisine. The inclusion complexes of cytisine alkaloid derivatives with β-CD and 2-HP-β-CD were obtained by the coprecipitation method. Thermogravimetric, differential thermal, and differential scanning calorimetric analyzes were performed. It was shown that inclusion complexes of substrate with cyclodextrin cavity of receptors were formed. The greatest change in the chemical shifts of protons during the formation of supra-molecular complexes occurs with the internal protons H-3 and H-5 of the cyclodextrin cavity. All calculated values are in good agreement with experimental data. The prepa-ration of supramolecular complexes has been proven using a variety of physicochemical methods of analysis. According to DSC data, the process of complexes destruction in the temperature range of 30-610°C was studied in comparison with the data of the initial cyclodextrin. The hemorheological effects of the investigated samples were studied in vitro. Among four samples studied, two samples showed the ability to reduce blood viscosity in vitro in the blood hyperviscosity model.

SOME DIRECTIONS IN THE MODIFICATION OF AZOLES

This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.