Hanna I. Severina

The aim. To investigate the potential antimicrobial activity of new heterocyclic derivatives with [(4-oxo-3,4-dihydropyrido[2,3-d]pyrimidin-2-yl)methoxy]acetic acid amide core, and to carry out the analysis of relationship between the structure and antimicrobial activity for the obtained amides. To determine via in silico methods whether inhibition of the TrmD active site is a possible mechanism of antimicrobial activity for the lead compounds identified through antimicrobial activity screening. Materials and methods. Organic synthesis methods; structure confirmation by ¹H, ¹³C NMR spectroscopy, LC-MS and HRMS analysis. The antimicrobial activity studies were carried out using agar-well diffusion method. Analysis of the suggested mechanism of antimicrobial activity was performed by the molecular docking method. Results. A rational synthetic scheme was developed for the preparation of [(4-oxo-3,4-dihydropyrido[2,3-d]pyrimidin-2-yl)methoxy]acetic acid. Because of the high-water solubility of this acid, isolation procedures were optimized to obtain a high-purity product with minimal moisture content, as residual moisture could interfere with subsequent synthetic steps. The amide coupling procedure for [(4-oxo-3,4-dihydropyrido[2,3-d]pyrimidin-2-yl)methoxy]acetic acid was optimized, and it was demonstrated that the use of 1,1'-carbonyldiimidazole as a coupling reagent enables the use of both substituted benzylamines and less reactive anilines. It was determined that the optimal ratio of solvent to acid mass is a twenty-fold excess of solvent. Screening of the synthesized amides for antimicrobial activity revealed that most of the compounds exhibited a greater tendency to inhibit the growth of Gram-negative bacteria. Antifungal activity was found to be more typical of the acid 4 rather than its amides; the activity of the acid 4 outperformed all the antibiotics tested in the experiment against the C. albicans ATCC885-653 fungal strain. The P. aeruginosa ATCC27853 strain proved to be the most sensitive to the majority of the compounds tested. Moreover, the activity of phenylamides 5—whether unsubstituted or bearing mild substituents on the benzene ring, such as a methyl group 5b or a methoxy group 5c proved to be the highest. Among the benzylamides, p-fluorobenzylamide 5i exhibited the greatest activity against P. aeruginosa ATCC27853. The obtained results of antimicrobial mechanism prediction suggest that the compounds 5 may inhibit TrmD competitively occupying the SAM-binding pocket. Nevertheless, static molecular docking results do not confirm the induction of a Tyr120 conformational rearrangement or the associated inhibition of substrate tRNA binding. Conclusions. An efficient synthesis of potential TrmD inhibitors based on amides of [(4-oxo-3,4-dihydropyrido[2,3-d]pyrimidin-2-yl)methoxy]acetic acid has been developed. It has been shown that the majority of the synthesized amides inhibits the growth of P. aeruginosa ATCC27853 and, according to docking studies, may inhibit TrmD by competitively occupying the SAM-binding pocket

The aim. Development and validation of a high-performance liquid chromatography (HPLC) method for the determination of related substances in a combined syrup containing ibuprofen (20 mg/mL) and caffeine (40 mg/mL), considering the results of stress degradation studies. Materials and methods. Chromatography was performed on an Agilent 1260 liquid chromatograph equipped with a diode-array detector using a Waters Symmetry C8 column (250 × 4.6 mm, 5 µm) in gradient elution mode at 25 °C and a flow rate of 1.0 mL/min. An aqueous solution of potassium dihydrogen phosphate (6.8 g/L) and sodium hexanesulphonate (0.4 g/L) (pH adjusted to 3.0 with phosphoric acid) was used as mobile phase A. Acetonitrile was used as mobile phase B. Detection was carried out at a wavelength of 210 nm. The injection volume was 15 µL. Stress degradation studies were conducted under the influence of elevated temperature (80 °C), light exposure, a 10% hydrogen peroxide solution (oxidation), as well as acid and alkaline hydrolysis. Validation of the method for determining related substances was performed in terms of specificity, linearity, accuracy, precision, and robustness, alongside the evaluation of the limit of detection and limit of quantitation in accordance with the requirements of the State Pharmacopoeia of Ukraine and ICH Q2(R2) guidelines. Results. Optimal chromatographic conditions were selected and substantiated during the development of an HPLC method for the determination of related substances, ensuring selective separation of ibuprofen, caffeine, excipients, and related substances (caffeine impurities A and F, ibuprofen impurity B). Stress degradation studies revealed that ibuprofen and caffeine in the syrup formulation are stable to light exposure and acid hydrolysis. Elevated temperature has the most significant degradation effect (resulting in the formation of ibuprofen impurity B and an unidentified caffeine impurity with a relative retention time of 1.05), whilst oxidation causes partial degradation of both active pharmaceutical ingredients (APIs). Alkaline hydrolysis leads to caffeine degradation, resulting in the formation of three unidentified products (relative retention times: 0.95, 1.03 and 1.05). The developed method is linear in the range of 0.025-1.0% (R2>0,999), accurate (mean recovery is 100.15 % for ibuprofen and 101.28% for caffeine), precise (relative standard deviation, %RSD, did not exceed 2.87%), specific, and robust. The LOQ for caffeine is 0.002%, and for ibuprofen 0.040%; the LOD is 0.0008% and 0.013%, respectively. Conclusions. An accurate, reproducible, and selective HPLC method for determining related substances in a combined liquid dosage form (ibuprofen and caffeine syrup) was developed and validated, taking into account stress degradation studies. Experimental studies substantiated the optimal chromatographic conditions

An effective one-step synthetic procedure for preparation of hydroxylated analogues of ethyl 2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate as novel promising multifunctional building blocks for drug discovery based on the Gewald procedure was developed.

The aim. To carry out the rational design, synthesis, and experimental evaluation of new glycine-linked thieno[2,3-d]pyrimidine hybrids as potential modulators of memory, anxiety, and pain for further correction of neurodegenerative processes, integrating in silico and in vivo investigations. Materials and Methods. Organic synthesis methods; structure confirmation by ¹H, ¹³C NMR spectroscopy, LC-MS, and elemental analysis. Molecular docking was performed using AutoDock Vina, AutoDockTools 1.5.6, and Discovery Studio Client. The pharmacological studies were carried out using a scopolamine-induced amnesia model and included the following behavioral assays: the Passive Avoidance Test, the Light-dark Transition Test, the Rotarod Test, and the Hot Plate Test. Results and Discussion. A series of newly designed glycine-linked thieno[2,3-d]pyrimidine hybrids was rationally developed, synthesized, and evaluated as potential modulators of neurodegenerative processes. The synthetic procedures for obtaining the intermediates and target 5-methylthieno[2,3-d]pyrimidin-4(3H)-one hybrids via amide coupling were optimized. Molecular docking to AChE (PDB ID: 7E3H) revealed that several derivatives, particularly 4d, 4f, and 4g, exhibited favorable binding energies (down to –12.5 kcal/mol) and formed an extensive network of hydrogen-bonding, halogen, π–π, and hydrophobic interactions within the active site of acetylcholinesterase. In vivo studies using the scopolamine-induced amnesia model demonstrated that these compounds display moderate anti-amnestic (pro-cognitive) properties and do not influence motor coordination or nociceptive sensitivity. Compound 4g showed anti-amnestic activity comparable to that of Donepezil, as well as pronounced anxiolytic effects. A correlation between the in silico predictions and the in vivo findings was established. Conclusions. The rational design, synthesis, and structural characterization of new AChE-targeted inhibitors, combined with in silico calculations and subsequent in vivo validation, enabled the identification of several thieno[2,3-d]pyrimidine derivatives with moderate anti-amnestic properties in the scopolamine-induced amnesia model, highlighting their potential as promising structures for further optimization

The aim. To apply the concept of bioisosterism for the structural optimization of benzimidazole–thieno[2,3-d]pyrimidine hybrids aimed at developing effective antibacterial agents as potential inhibitors of the bacterial enzyme TrmD. Materials and Methods. Organic synthesis methods; structure confirmation by ¹H, ¹³C, and HMBC NMR spectroscopy, LC-MS, and elemental analysis. Molecular docking was performed using AutoDock Vina, AutoDockTools 1.5.6, and Discovery Studio Client. Antimicrobial activity was evaluated using the agar diffusion method, and the impact on biofilm formation/disruption was assessed using the crystal violet assay. Results and Discussion. The bioisosteric modification involved oxidation of the thione group in 3,5-dimethyl-4-oxo-2-thioxothieno[2,3-d]pyrimidine-6-carboxylate. The resulting 2,4-dioxothieno[2,3-d]pyrimidine-6-carboxylic acid was activated with 1,1′-carbonyldiimidazole to form a benzimidazole fragment in a one-pot procedure. Alkylation of the obtained hybrid with chloroacetamides led to regioselective products confirmed by HMBC. All synthesized compounds demonstrated significant antimicrobial activity against both Gram-positive and Gram-negative test strains. Compound 5c with a 4-ethoxyphenyl substituent processed the highest activity, including effectiveness against clinical strains of S. aureus and P. aeruginosa. Compound 5c also demonstrated notable biofilm disruption capacity against S. aureus, E. coli, P. aeruginosa, and C. albicans. Molecular docking to the TrmD bacterial enzyme confirmed the formation of a hydrogen bond between the 2-oxo group and Glu121. Conclusions. An efficient method was developed for the synthesis of a novel series of 2-[6-(1H-benzimidazol-2-yl)-3,5-dimethyl-2,4-dioxo-3,4-dihydrothieno[2,3-d]pyrimidin-1(2H)-yl]-N-arylacetamides. Bioisosteric hybrids showed enhanced antimicrobial properties and improved binding affinity to bacterial TrmD. Compound 5c demonstrated high activity against both Gram-positive and Gram-negative strains, including clinical isolates, as well as the ability to disrupt biofilms, highlighting its potential as a promising lead for further development

The search for neuroprotective compounds in lavender is driven by its traditional use for brain health, with antioxidant activity serving as a key mechanism in reducing oxidative stress and supporting cognitive function. Lavender’s potential to protect neurons is based on its calming, anti-stress properties, which increase the brain’s resistance to neurodegeneration. Although lavender is not a traditional medicinal plant in Ukraine, it is increasingly recognised for its medicinal properties and is widely cultivated in the country. Lavender use in Ukraine is influenced by both global herbal practices and local medical traditions. The aim of this study was to optimise the preparation of lavender herb extracts, perform chemical profiling and evaluate their antioxidant and neuroprotective activities. The study focused on Lavandula angustifolia cultivated in Lviv, Ukraine. Modern analytical methods were used, including HPLC, spectrophotometry, molecular docking, lyophilisation and pharmacological testing. The selection of the optimal conditions for obtaining lavender herb extracts was determined on the basis of the results of the total yield of phenolic compounds in each extract, where it was found that the raw material–solvent ratio (1:10) in water and 50% ethanol gave the highest yield of substances; the preferred extraction time was 20 min, and the temperature was 60–70 °C, especially for water extraction. Further HPLC analysis identified marker compounds including rosmarinic acid (28.31 mg/g), chlorogenic acid (1.64 mg/g) and luteolin (0.23 mg/g) in the lyophilised ethanol extract, which were previously recognised as neuroprotective markers by molecular docking. The water extract showed higher antioxidant (total 50.85 mg/g) and neuroprotective activity, probably due to synergistic interactions among the components. Behavioural tests further demonstrated the neuroprotective potential of lavender herb. These results demonstrate the potential neuroprotective activity of lavender herb and open new possibilities for its use in the treatment of various neurodegenerative diseases.

Background: Designing novel biologically active compounds with anti-inflammatory properties based on condensed quinazolines is a significant area of interest in modern medicinal chemistry. In the present study, we describe the development of promising new bioactive molecules through the bioisosteric replacement of a carbon atom with a sulfur atom in anti-inflammatory agents, specifically 3-methyl-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)butanoate. Methods: Design and synthetic studies have led to the series of previously unknown substituted 2-[((3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)methyl)thio]carboxylic acids and their esters. These compounds were synthesized by reacting 6-chloroalkyl-3-R-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones with sulfanylalkyl carboxylic acids and their functional derivatives. The purity and structure of the obtained compounds were confirmed using a set of physicochemical methods, including elemental analysis, HPLC-MS, and ¹H NMR spectroscopy. Molecular modeling, predicted toxicity, drug-likeness, and pharmacokinetics data were used to select compounds for evaluation of their effects on acute aseptic inflammation (carrageenan-induced paw edema test) and on markers of the inflammatory process. Results: The compound 2-((1-(3-methyl-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)ethyl)thio)acetic acid (compound 2e) was identified as the most active anti-inflammatory agent (AA = 53.41%), demonstrating significant inhibition of both paw edema development and the generation of pro-inflammatory cytokines and mediators. Conclusions: Results from docking studies and analysis of “structure-affinity” correlations revealed that these compounds are promising candidates for further modification and detailed investigation of their anti-inflammatory activity

Designing novel biologically active compounds with anti-inflammatory properties based on condensed quinazolines is a significant area of interest in modern medicinal chemistry. In the present study, we describe the development of promising new bioactive molecules through the bioisosteric replacement of a carbon atom with a sulfur atom in anti-inflammatory agents, specifically 3-methyl-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)butanoate. Design and synthetic studies have led to the series of previously unknown substituted 2-[((3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)methyl)thio]carboxylic acids and their esters. These compounds were synthesized by reacting 6-chloroalkyl-3-R-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones with mercaptoalkyl carboxylic acids and their functional derivatives. The purity and structure of the obtained compounds were confirmed using a set of physicochemical methods, including elemental analysis, HPLC-MS, and 1H NMR spectroscopy. Molecular modeling, predicted toxicity, drug-likeness and pharmacokinetics data were used to select compounds for evaluation of their effects on acute aseptic inflammation (carrageenan-induced paw edema test) and on markers of the inflammatory process. The compound 2-((1-(3-methyl-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)ethyl)thio)acetic acid (compound 2.5) was identified as the most active anti-inflammatory agent, demonstrating significant inhibition of both paw edema development and the generation of pro-inflammatory cytokines and mediators. Results from docking studies and analysis of "structure-affinity" correlations revealed that these compounds are promising candidates for further modification and detailed investigation of their anti-inflammatory activity

The presented material describes the results of the purposeful search for the novel hepatoprotective agents among synthetic sulfur-containing pteridines. The studied compounds were obtained using previously described synthetic procedures. SwissADME and ProTox-II services, as well as a docking study were used to predict the compounds` pharmacokinetics, drug-likeness and toxicity. The effects of sulfur-containing pteridines on lipid peroxidation in vitro and GSH/GSSG levels in vivo were studied for evaluation of their hepatoprotective potential. In silico procedures allowed us to exclude the compounds with inappropriate ADME parameters and high predicted toxicity. Molecular docking of the obtained compounds towards the active site of CYP-enzyme allowed us to clarify the specifics of ligand-enzyme interactions and predict cytochrome-inhibiting activity of the studied agents. The antioxidant activity of the studied compounds was evaluated in vitro using the linoleic acid peroxidation model. It has been found that sulfur-containing pteridines inhibit the peroxidation of linoleic acid. The structure – antioxidant activity relationships were evaluated and discussed as well. Additionally, it has been estimated that antioxidant properties of the studied pteridines directly correlate with their hydrophilicity and number of functional groups with exchangeable proton in molecules. In vivo studies showed that some of the studied sulfur-containing pteridines reduced severity of the hepatotoxic effects caused by the administration of carbon tetrachloride. (3-(7-Hydroxy-4-oxo-2-thioxo-1,2,3,4-tetrahydropteridin-6-yl)propanoyl)alanine has been identified as the most active hepatoprotective agent. The above mentioned compound significantly increases the content of GSH and decreases the level of GSSG compared with non-treated experimental pathology, which reliably affirms its hepatoprotective activity. The hepatoprotective activity of the studied compounds is likely associated with their ability to increase the level of GSH, inhibit lipid peroxidation and decrease prooxidant compounds levels. The obtained results attest the reasonability of further search for hepatoprotective agents among sulfur-containing pteridine derivatives.

Pineapple weed (Matricaria discoidea DC.) is a widespread plant in Europe and North America. In ethnomedicine, it is well-known for its anti-inflammatory and spasmolytic activities. The aim of this research was to develop novel methods of M. discoidea processing to obtain essential oil and dry extracts and to investigate their phytochemical compositions. Moreover, the molecular docking of the main substances and the in vivo studies on their soporific and analgesic activities were conducted. The essential oil and two dry extracts from M. discoidea were prepared. A total of 16 phenolic compounds (seven flavonoids, seven hydroxycinnamic acids, and two phenolic acids) in the dry extracts were identified by means of UPLC-MS/MS. In the essential oil, nine main terpenoids were identified by gas chromatography (GC). It was shown that phenolic extraction from the herb was successful when using 70% ethanol in a triple extraction method and at a ratio of 1:14–1:16. The in vivo studies with rodents demonstrated the analgesic activity of the M. discoidea extracts and improvements in the sleep of animals. The dry extracts of M. discoidea did not show any toxicity. The molecular docking analysis showed a high probability of COX-1,2 inhibition and NMDA receptor antagonism by the extracts.