Bioorganičeskaâ himiâ

Chronic myeloid leukemia (CML) is a malignant disease of the hematopoietic system with a key pathogenic protein BCR-ABL, which seriously threatens the lives of patients. The first drug based on the inhibition of the hybrid tyrosine kinase BCR-ABL, the gene of which is located on the "Philadelphia chromosome", was imatinib. Imatinib therapy turned out to be quite successful: patients with CML achieved a complete cytogenic response 2 years after the start of treatment and a state of stable remission for a long time. However, the inevitable resistance to imatinib, which occurs in clinical settings due to mutations in the BCR-ABL kinase, gave impetus to the development of new specific drugs, such as dasatinib, nilotinib, bosutinib and ponatinib. Currently, the pharmaceutical market offers the second and third generations of BCR-ABL tyrosine kinase inhibitors designed to combat mutant BCR-ABL and possessing better selectivity. It is noteworthy that the first allosteric inhibitor that can effectively overcome mutations in the ATP binding site has appeared on the market. In recent years, chimeras aimed at proteolysis (PROTAC) based on another E3 ligand have come into use, as a result of which they are able to overcome drug resistance due to selective degradation of target proteins. Data on inhibitors that have received the status of approved drugs for the treatment of CML are presented. Promising areas for the development of new BCR-ABL inhibitors are indicated. The relevance of this area of research is confirmed by the emergence of a significant number of new publications on this topic.

Three-dimensional microscopy (3D microscopy) has become an important tool in cellular analysis and biomedical research, providing unique opportunities to visualize and study complex biological structures. The capabilities of different types of microscopies in studying cellular structures and macromolecular complexes span a wide range of scales, from investigating cell behavior and function in physiological environments to understanding the molecular architecture of organelles. At each scale, the challenge of 3D imaging is to extract the highest possible spatial resolution while minimizing damage to living cells. This review highlights the various applications of 3D microscopy in areas such as cancer research, viruses, bacterial properties and structure, and organ and implant microstructure analysis.

Synthesis was carried out with the selection of conditions for the isolation and purification of fluorescently labeled polyethylene glycol with a reactive carboxyl group for labeling biomolecules. Pegylated nucleotides, which are part of drugs, allow targeted delivery to the target organ, prolong the half-life, reduce immunogenicity and increase stability.

Hemolysin II (HlyII) is one of the key pathogenic factors of the opportunistic gram-positive bacterium Bacillus cereus. HlyII lyses target cells by forming pores on membranes. HlyII belongs to the group of β-pore-forming toxins. A distinctive feature of HlyII is the presence of a C-terminal domain of 94 amino acid residues (HlyIICTD). It was shown that under slightly acidic conditions (pH 5.0), corresponding to the near-membrane region, the C-terminal domains, both by themselves and as part of the toxin, form stable complexes consisting of full-length and truncated toxin molecules. HlyII, HlyIILCTD (large C-terminal fragment Met225–Ile412) and HlyIICTD were obtained using recombinant producer strains Escherichia coli BL21(DE3). Biotinylation of HlyIICTD was carried out using N-hydroxysuccinimide ester of biotin. The interaction of HlyIICTD with HlyIICTD, HlyIILCTD, and HlyII, as well as the interaction of HlyIICTD with erythrocyte membranes, were studied by enzyme-linked immunosorbent assay and immunoblotting using both horseradish peroxidase-conjugated streptavidin and monoclonal antibodies against HlyII. Under slightly acidic conditions, HlyIICTD interacted with both the HlyIICTD domain within the full-length toxin and with the HlyIICTD protein. The interaction of HlyIICTD with the erythrocyte membrane increased fold in the presence of the toxin. The property of the C-terminal domain to form complexes with each other was revealed, regardless of whether it is part of the full-length toxin, the large C-terminal fragment, or the short HlyIICTD under conditions corresponding to those existing near the cell membrane (pH 5.0). The toxin in the peri membrane region exists in a partially molten globule state, in which the C-terminal domains of the monomers can bind to each other, increasing the local concentration of full-length toxins.

The determination of bioavailability during the study of the therapeutic potential of plant extracts is extremely important because it serves as an indicator of whether the original compounds will retain their biological activity or gradually lose it under the influence of multiple factors. Rosemary (Rosmarinus officinalis L.) is the source with the highest percentage of the pentacyclic triterpenoid ursolic acid, while ecdystene (20-hydroxyecdysterone) is one of the main phytoecdysteroids present in leuzea (Rhaponicum carthamoides Willd.). Both plant sources are distributed on the pharmaceutical market in the form of food and dietary supplements as metabolic therapy agents. However, there is still little information on the pharmacokinetic profile of ecdystene and ursolic acid in extracts and multicomponent compositions. In this paper, we carried out a comparative evaluation of pharmacokinetic parameters of ecdystene, ursolic acid, extracts of leuzea and rosemary, composition based on the two extracts in blood during per os administration in vivo. Methods: The investigated substances and their extracts were administered once, intragastrically to CD-1 outbred mice in doses equivalent in quantitative content of the main active substance. The content of ursolic acid and ecdystene in animal blood was determined by HPLC-MS/MS for subsequent calculation of pharmacokinetic parameters (Cmax, Tmax, AUC). Results: In both cases there was a decrease in bioavailability of ursolic acid and ecdystene in the blood of experimental animals in comparison with individual substances. In the composition, only trace amounts of ecdystene were determined, while no differences in pharmacokinetic parameters of ursolic acid in the composition and rosemary extract were found. Conclusions: This study proves that the combination of plant extracts in the form of multicomponent mixtures can lead to a decrease in bioavailability of the main active substances by many different factors. The development of products based on plant extracts should be accompanied by pharmacokinetic studies to prove the quality of the finished product.

The paper presents the results of synthesis of a new amide derivative of betulinic acid – N-[1-(1-adamantyl)-ethyl]-3-hydroxylup-20(29)-en-28-amide containing a pharmacophoric 1-(1-adamantyl)ethylamine group in its structure and evaluation of its antiviral action in vitro and in vivo. It was found that the minimum inhibitory dose of the substance was 31.2 µg/mL. The highest antiviral activity was observed with 2–3 times the administration of the compound to guinea pigs. The obtained results allow us to recommend the studied compound for testing on cattle.

This study aims to synthesize and evaluate the antitumor efficacy of a series designed chimeric amides (10–14, 16, 19, 21, 25–27, 28, 30) containing various combinations of nitrogen-containing heterocycles, which are the key pharmacophores of many antitumor drugs with different mechanisms of action. The designed amides were synthesized and characterized using spectroscopic techniques. The antitumor activity of all these compounds against tumor cell lines K562 (chronic myeloid leukemia), HL-60 (acute promyelocytic leukemia), and HeLa (cervical carcinoma) was assessed in vitro in terms of the values of half-maximal inhibitory concentration (IC50). As a result, 5 lead compounds, amides (10, 11, 21, 27, 30), active against the above cell lines were identified followed by in silico analysis of their pharmacological properties and prediction of the most probable mechanism of action against myeloid blood cells K562. In light of the data obtained, the identified compounds were shown to form promising basic structures for the design of novel orally active antitumor agents, multi-target protein kinase inhibitors.

Obtaining a fraction of double-stranded RNA is an integral part of any RNA interference research whether it aimed at solving fundamental or applied problems. The production of dsRNA in bacterial culture is a common technique due to its comparative cheapness and scaling-up opportunities. In this article, we propose a new method for fast and effective isolation of dsRNA from bacterial culture, as an alternative to classical phenol-chloroform extraction. In our method, phenol is replaced with less toxic methanol, and the total RNA thus isolated from bacteria contains up to 25% of the target molecule lacking the DNA contamination, which enables its usage in certain further applications without additional cleanup steps. The application of this methodology will be justified in laboratories engaged in either fundamental or applied research on RNA interference. However, scaling the technology for agricultural use may require adjustments to the protocol described in this work.