Russian Journal of Bioorganic Chemistry最新文献

Objective: Composite aerogel materials based on the complex of alginate and chitosan with the introduction of active additives (magnetite and vaterite) were obtained and their consumer properties were studied to assess the possibility of using them as hemostatic materials. Methods: A texture analyzer and scanning electron microscopy were used to determine the structure of the prepared samples. To assess the possibility of using the materials in medicine, an antimicrobial activity test was conducted. The in vivo experiments were performed to study the cessation rate of bleeding. Results and Discussion: It was shown that the developed materials are characterized by a developed micro-mesoporous structure, which provides a high moisture absorption capacity in relation to a saline solution that simulates the pH of warm-blooded animals. The maximum absorbency was 67 and 43 g/g for the material containing vaterite and magnetite, respectively, due to differences in the porous structure of the samples. The results of testing the antimicrobial activity of the materials confirmed the possibility of their use for biomedical purposes. The antibacterial activity of the materials against the microorganisms Staphylococcus aureus and Bacillus subtilis is most pronounced, the diameters of the growth suppression zones of which reached 24 ± 0.2 and 20 ± 0.2 mm. A comparative analysis of the hemostatic activity of the developed materials in an in vivo experiment showed that the developed materials are characterized by a high rate of cessation of bleeding compared to a cotton swab: the blood clotting time in the experimental group for a material containing vaterite and magnetite was 32.64 and 49.61 s, respectively, which is 1.3–2 times less than in the control group. Conclusions: The performed studies have shown that composite aerogel materials based on a complex of sodium alginate and chitosan with the introduction of active additives (magnetite and vaterite) can compete seriously both on the international and Russian market of hemostatic drugs and medical devices.

Objective: The objective of this study, taking into account the available data on the biological activity of various chloramphenicol analogues, is to search for new effective compounds with antibacterial and fungicidal properties among N- and O-acyl derivatives of CAM, as well as to conduct a docking study on four different targets to clarify the possible further direction of research on the synthesis of biologically active chloramphenicol analogues. Methods: Antibacterial and antifungal activity were determined by the agar diffusion method. Taking into account the relevance of the search for new effective antiviral, antitumor and neurotropic drugs, a docking study of the synthesized compounds (ligands) was carried out in relation to the complex of RNA-dependent RNA polymerase (RdRp) with the NSP7 and NSP8 proteins of the SARS-CoV-2 virus, the kinase domain of the human epidermal growth factor receptor (EGFR), doubly phosphorylated human mitogen-activated protein kinase 14 (MAPK14) in a complex with the activator of the transcription factor (ATF2) and human monoamine oxidase B in a complex with 2-(2-benzofuranyl)-2 imidazoline (2-BFI). Results and Discussion: The results of the docking analysis of the studied compounds showed that the most active compound, 3-hydroxy-3-(4-nitrophenyl)-2-{[(2-phenylquinolin-4-yl)carbonyl]amino}propyl 2-phenylquinoline-4-carboxylate, strongly interacts with the SARS-CoV-2 RNA-dependent RNA polymerase has a binding energy ΔG₀ = –10.435 kcal/mol. The interaction energy for the human EGFR kinase domain ΔG₀ = –12.633 kcal/mol, while for the phosphorylated human MAPK14, it is –13.436 kcal/mol. A number of the studied compounds exhibited high antimicrobial activity against Staphylococcus aureus and Bacillus subtilis, but significantly less against a strain of Escherichia coli. The most active benzofuran-based derivative demonstrated relatively high activity against S. aureus, B. subtilis, and Candida albicans, comparable to the control compounds. Conclusions: The study demonstrates the feasibility of using structural analogs. Biological studies have identified antibiotic analogs that exhibit relatively high activity against S. aureus, B. subtilis, and C. albicans. Based on docking analysis data, new chloramphenicol analogs can be predicted to exhibit antiprotein kinase activity against the human epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase (MAPK). The antibacterial and antifungal properties of the synthesized chloramphenicol analogues create the preconditions for the development of new effective drugs for the treatment of bacterial and fungal infections, and the results of docking analysis also indicate the possibility of creating antitumor drugs.

Objective: Libraries of mutant variants of fluorogen-activating protein picoFAST were constructed and screened for improved brightness of [protein-HBR-DOM2] complex. Methods: Random mutagenesis of picoFAST by error-prone PCR was done. The screening of mutant variant was conducted. Selected picoFAST variants were sequenced and result was analyzed. New round of saturation mutagenesis was done and obtained colonies were screened. Results and Discussion: We constructed mutant libraries of picoFAST through optimized random mutagenesis protocols, achieving an average of 3.75 nucleotide substitutions per picoFAST coding sequence. Screening of approximately 1.5 × 10⁴ bacterial colonies expressing mutant variants yielded 10 picoFAST mutants exhibiting high brightness. Structural predictions using AlphaFold indicated that substitutions localized in the N- and C-terminal β-strands modulate the fluorogen-binding pocket conformation and fluorescence activation, providing insights for rational design and targeted mutagenesis to further improve fluorogenic performance. Conclusions: We obtained and analyzed libraries of mutant forms of the fluorogen-activating protein. We have outlined promising directions for further enhancement of the smallest fluorogen-activating protein currently known. The improved picoFAST variant could be useful for visualizing tag-sensitive proteins and densely packed cellular structures.

Objective: The aim of this study was to synthesize a new group of acyl derivatives based on methyl esters of 1β-hydroxy- and 1β,4α-dihydroxy-2,3-dihydroquinopimaric acid and evaluate their antioxidant potential. Methods: Acylation of methyl esters of 1β-hydroxy- and 1β,4α-dihydroxy-2,3-dihydroquinopimaric acid with acyl chlorides was carried out by boiling in absolute pyridine for 8 h in the presence of 4-dimethylaminopyridine (DMAP) catalyst. The structure of the synthesized acylates was confirmed by NMR spectroscopy and mass spectrometry data. The antioxidant activity of the synthesized compounds was assessed using two in vitro models: Ferric Reducing Antioxidant Power (FRAP) and the ABTS cation-radical reduction. Results and Discussion: Methyl ester of 1β,4α-dihydroxy-2,3-dihydroquinopimaric acid exhibits versatile antioxidant activity, effectively acting in both the FRAP and ABTS models. Furthermore, four of the synthesized acylates exhibit significantly higher reducing potential than the parent compounds, highlighting the potential for further optimization of these derivatives to create effective antioxidant agents. Conclusions: The identified activity characteristics highlight the potential for further structural optimization of the studied compounds to create effective antioxidant agents with a defined action profile. Expanding the range of models, in-depth study of the mechanisms of antioxidant and prooxidant action, and research into metabolic stability, bioavailability, and interactions with cellular targets will enable the creation of effective and safe antioxidant drugs with a specified action profile.

Objective: The aim of this study was to test the applicability of a rheumatoid arthritis (RA) model to develop radioligands based on structural analogs of honokiol (SAH) for neuroinflammation imaging with positron emission tomography (PET). Methods: The RA model was induced in C57BL/6 mice and Wistar rats using complete Freund’s adjuvant (CFA). SAHs with a fluoroethoxy moiety were synthesized by the Suzuki-Miyaura reaction. Ligand F-I (2-hydroxy-4′-(2-fluoroethoxy)-5-ethoxy-1,1′-biphenyl) was selected due to its optimal biochemical characteristics (lipophilicity, metabolic stability, etc.) for testing in the RA model. Labeled with fluorine-18 (T_1/2 = 109.8 min) SAHs were obtained by ¹⁸F-fluoroethylation of Boc-monoprotected biphenyls. The biodistribution of [¹⁸F]F-I was studied in rats with CFA-induced RA. Results and Discussion: In mice with CFA-induced RA, F-I demonstrated significant suppression of peripheral inflammation (paw swelling) by ~30% and neuroinflammation (neuronal damage) in the associative cortex by ~60%. However, preliminary studies of [¹⁸F]F-I biodistribution in CFA-induced arthritis rats showed only a slight increase in radioactivity uptake in the brain compared to intact animals. Pretreatment with unlabeled F-I or celecoxib resulted in reduced [¹⁸F]F-I uptake, likely indicating specific binding to cyclooxygenase-2 (COX-2). Conclusions: The results of our pilot experiments demonstrated that the CFA-induced RA model can be used to evaluate potential inhibitors of neuroinflammation. Future efforts will focus on adapting the RA model to develop radioligands based on SAHs with anti-inflammatory activity.

Objective: Cervical cancer remains a significant global health concern, necessitating the development of targeted therapies with enhanced efficacy and reduced side effects. Current treatment approaches, such as surgery combined with chemotherapy and radiotherapy, often cause severe adverse effects due to their non-specificity, which drives the need for targeted therapies. The overexpression of folate receptors (FRs) in many cervical cancer cells makes them a promising target for drug delivery. This study focuses on the synthesis and evaluation of a conjugate of ursolic acid and folic acid (UA-FA) as a potential anticancer agent. Methods: In silico studies, including molecular docking and molecular dynamics (MD) simulations, were performed to assess the binding affinity of the UA-FA conjugate to the folate receptor α (FRα; PDB ID: 4LRH). ADME/T predictions were performed. The UA-FA conjugate was synthesized via a multi-step reaction involving the conversion of ursolic acid into its hydrazide derivative, followed by conjugation with the γ-carboxyl group of folic acid. In vitro cytotoxicity assays against HeLa (cervical carcinoma) and Vero (normal kidney epithelial) cell lines were performed. Results and Discussion: Docking results revealed strong interactions with a more favorable binding energy compared to ursolic acid alone. MD simulations confirmed the stability of the receptor-ligand complex over a 100 ns trajectory. ADME/T predictions indicated improved pharmacokinetic properties, including aqueous solubility and oral bioavailability. In vitro cytotoxicity assays demonstrated selective toxicity toward cancer cells, with an IC₅₀ of 105.79 ± 2.23 μg/mL and a selectivity index (SI) of 2.07, compared to UA alone (SI = 1.78). Conclusions: These findings suggest the UA-FA conjugate as a promising candidate for targeted cervical cancer therapy. Further in vivo studies are warranted to confirm its therapeutic potential.

Objective: A new green fluorescent protein chromophore analogue with an sp-hybridized carbon fragment was presented. Methods: The introduction of a protecting group, Sonogashira coupling, and subsequent hydrolysis were used for the synthesis of aldehyde. The formation of imine of the corresponding aldehyde with the subsequent [3+2] cycloaddition and deprotection were used for the synthesis of arylpropynylidene-imidazolone. The optical properties of the new compound were studied. Results and Discussion: We discovered that the new substance, which has a triple bond in conjugation with the aromatic part of the molecule, is characterized by a bathochromic shift of the absorption and emission maxima. The resulting compound is comparable in its spectral characteristics with the previously synthesized arylallylidene-imidazolone. Conclusions: We designed a new green fluorescent protein chromophore analogue with an sp-hybridized carbon fragment that demonstrates a bathochromic shift of spectral maxima. The new substance can be potentially used as a fluorogenic dye for living systems.

Objective: The aim of this study was to study the effect of the LKEKK peptide on the rat myocardium in normal conditions and after experimental myocardial infarction (EMI). Methods: EMI was modeled in rats by ligating the anterior descending branch of the left coronary artery. Under ether anesthesia, the animal's skin and subcutaneous fat were incised, and the pectoral and intercostal muscles were separated along their fiber course. After opening the chest, the heart was removed through the surgical wound, and the left coronary artery was sutured and ligated. The onset of myocardial ischemia was monitored electrocardiographically. Results and Discussion: It was found that [³H]LKEKK binds with high affinity and specificity to the membranes of the rat myocardium before EMI (K_i = 1.9 nM). One hour after the operation, a sharp decrease in binding affinity was observed (K_d = 13.4 nM), after 24 h it increased significantly (K_d = 3.5 nM), and after 72 h it was almost completely restored (K_d = 2.1 nM). It was established that therapy of EMI with Riboxin (orally at a dose of 10 mg/kg once a day for 7 days after infarction) together with the peptide LKEKK (intranasally at a dose of 500 µg/rat according to the same scheme) has a pronounced anti-ischemic effect: improves coronary blood flow in the post-infarction period; increases myocardial contractility in the post-infarction period, promotes normalization of atrioventricular conduction disorders of the myocardium. A reliable decrease in the intensity of myocardial cytolysis and lipid peroxidation is also noted. All of the listed effects were more pronounced than in the case of Riboxin therapy without the peptide. Conclusions: The study demonstrates that the peptide can be used in complex therapy of ischemic heart disease and myocardial infarction.

Objective: The aim of this study was to identify antibodies to peptides representing conserved Bcell epitopes of hepatitis C virus (HCV) envelope proteins E1 and E2, and to evaluate their significance for predicting viral elimination in patients undergoing directacting antiviral (DAA) therapy. Methods: Nine peptides derived from HCV envelope proteins E1 and E2 were synthesized using the solidphase method. Immunoreactivity of the peptides was assessed via a solidphase enzymelinked immunosorbent assay (ELISA) using serum samples from 9 patients with acute hepatitis C and 67 patients with chronic hepatitis C who received DAA therapy. Statistical significance was evaluated using pvalues. Results and Discussion: The presence of antibodies to the E1E2 complex before treatment, as demonstrated by other researchers, is associated with the achievement of a sustained virological response (SVR) in 70% to therapy with DAAs, and thus may serve as a predictive marker (p = 0.012). However, the possible predictive role of individual B-epitopes of HCV envelope proteins has not yet been clarified. The study revealed that the presence of antibodies to two peptides representing conserved immunodominant Bepitopes of the E2 protein was associated with achieving SVR in 73.0 and 89.2% of patients (p = 0.00001 and p = 0.0086, respectively). These findings suggest that antibodies targeting specific Bepitopes of HCV envelope proteins may serve as positive prognostic markers for treatment outcome. The results highlight the potential of using antibody profiles to improve prediction of therapy success, enable personalized treatment approaches, and inform vaccine development. Conclusions: The presence of antibodies to conserved immunodominant Bepitopes of the HCV E2 protein is a promising positive prognostic marker for achieving SVR in patients treated with DAAs. The obtained data can be used to improve methods for predicting therapy outcomes, develop personalized approaches to treatment, and develop vaccines against viral hepatitis C.

Objective: A new library of sydnonimines containing a carboxyethyl group at the exocyclic nitrogen atom was presented. Methods: Four-step synthesis including cyanomethylation, N-nitrosation, cyclization, and final introduction of a carboxyethyl group was used to obtain new sydnonimines. Results and Discussion: We discovered that the proposed approach can be optimized for a gram-scale synthesis with a single chromatographic step. Our method can be applied to obtain libraries of potential biologically active compounds of this class. Conclusions: We designed a new series of sydnonimines with a carboxyethyl group at the exocyclic nitrogen atom. Going forward, the synthesized substances can be potentially used in new promising drug design.