Introduction: Cancer remains a major cause of mortality worldwide; therefore, research continues to focus on the development of more effective therapeutic agents. Methods: In this study, the cytotoxic effects of a series of uracil-quinazoline hybrids were evaluated against A549 (lung cancer) and HepG2 (hepatocellular carcinoma) cell lines using the MTT assay. Results: The biological results demonstrated that several of the studied hybrids exhibited significant cytotoxic activity against both A549 and HepG2 cell lines compared to the reference drugs Erlotinib (IC50 = 35.5 ± 0.4 μM for A549; 13.1 ± 0.2 μM for HepG2) and Cisplatin (IC50 = 15.4 ± 1.6 μM for A549; 15.9 ± 1.8 μM for HepG2). Among the studied hybrids, compound 3f showed the highest anti-proliferative activity against A549 cells, with an IC50 value of 5.4 ± 1.3 μM, while compounds 3g and 3i displayed superior cytotoxic activity against HepG2 cells, with IC50 values of 6.9 ± 3.0 μM and 3.3 ± 1.7 μM, respectively. Molecular docking studies and Molecular Dynamics (MD) simulations revealed that the binding interactions of the active hybrids within the Cyclin-Dependent Kinase 2 (CDK2) active site were consistent with the biological findings, suggesting CDK2 as a potential molecular target. Furthermore, Density Functional Theory (DFT) calculations were performed to theoretically evaluate the Frontier Molecular Orbital (HOMO and LUMO) energy levels, chemical reactivity, and molecular stability of selected hybrids. discussion: Molecular docking studies and MD simulation revealed that the binding interactions of the active hybrids within the Cyclin-dependent kinase 2 (CDK2) active site were consistent with the biological findings, suggesting CDK2 as a potential molecular target. Furthermore, density functional theory (DFT) analysis was performed to theoretically evaluate the frontier molecular orbital (HOMO and LUMO) energy levels, chemical reactivity, and molecular stability of several hybrids. Discussion: These findings highlight the therapeutic potential of uracil-quinazoline hybrids, particularly compounds 3f, 3g, and 3i, as potent inhibitors of lung and liver cancer cell growth, with activities superior to those of standard drugs. The consistency between experimental cytotoxicity results, molecular docking, MD simulation, and DFT analyses supports CDK2 as a plausible molecular target and provides insight into the structure-activity relationships governing their anticancer effects. This integrated computational-experimental approach strengthens the rationale for further development of these hybrids as targeted anticancer agents. Conclusion: These findings provide a strong foundation for future optimization and in vivo evaluation of uracil-quinazoline derivatives as targeted cancer therapeutics.
The structural variety and associated biological potential of pyrimidine derivatives have made them attractive to medicinal chemists. Due to the various biological activities of Pyrimidine derivatives and structural derivatives of DNA, many researchers have been prompted to explore this area. Substituted Pyrimidine derivatives have a broad range of pharmacological applications, including antimicrobial, anticancer, and anti-inflammatory activities. The pyrimidine ring and its fused derivatives, which include pyrazolo[3,4-d]pyrimidine, pyrido[2,3- d]pyrimidine, quinazoline, and furo[2,3-d] pyrimidine, have generated a great deal of attention due to the high variety of biological potential that they possess. In addition, fused pyrimidines are intended as bioisosteres of purines. As a result, numerous substances, including pyrimidines and fused pyrimidine derivatives, have demonstrated promising anticancer potential. The emergence of multidrug resistance in cancer cells has significantly reduced the effectiveness of numerous anticancer drugs, posing a challenge to cancer treatment. To avoid this issue, researchers are continuously focusing on target-based drug discovery as a promising pathway for developing novel anticancer agents with improved efficacy and selectivity. Specifically, this review will explore various pyrimidine derivatives, examining positional substitutions and fusion with other heterocyclic rings to elucidate how these compounds interact with molecular targets involved in cancer development and progression. By understanding these interactions, researchers can design more potent pyrimidine -based drugs with better target selectivity. Moreover, the review will also explain the structure-activity relationships of various pyrimidine derivatives, providing insights into the structural features that contribute to their anticancer activity. In the past few years, numerous novel pyrimidine derivatives have been developed and studied for their anticancer activities. The primary objective of this review is to evaluate the structureactivity relationship (SAR) of pyrimidine derivatives developed as anticancer agents over the past decade.
INTRODUCTION:Exchange proteins directly activated by cyclic AMP (Epac) represent a promising therapeutic target for developing novel cardiotropic agents. Epac-dependent signaling regulates intracellular calcium dynamics, intercellular coupling, and the contractile function of cardiomyocytes. Preclinical studies have demonstrated the potential of Epac2 inhibitors for the treatment of cardiovascular diseases (CVDs). METHODS:New potential Epac protein inhibitors from the series of arylsulfonylaminopyridines were designed using pharmacophore modeling, molecular docking, ADMET analysis, and molecular dynamics. The compounds were synthesized via the reaction of N-substituted aminopyridines with arylsulfonyl chlorides. The potential cardiotropic activity of the synthesized compounds was evaluated ex vivo using a model of an isolated rat atrial myocardial strip. RESULTS:Pharmacophore-based design led to novel aminopyridine derivatives predicted to interact with Epac2. Computational studies suggested stabilization of the inactive conformation of Epac2. Ex vivo experiments revealed changes in myocardial contractility that are consistent with the proposed hypothesis of Epac2 involvement, although further studies are required to establish direct target engagement. DISCUSSION:A key objective of this study was to refine the ligand-binding pocket of Epac2, as preliminary in silico analyses revealed discrepancies with previously reported models. In parallel, the potential for PKA-independent Epac2 involvement was assessed using ZMEI-26 in a forskolin-based experimental setup. The combined computational and functional data suggest possible Epac2 engagement and are consistent with the proposed mechanism, although further studies are required to confirm direct target interaction. CONCLUSION:A new series of aminopyridine derivatives was created using molecular modeling methods as potential Epac2 inhibitors. During the synthesis, 11 compounds (coded ZMEI) were obtained, several of which (ZMEI-3, ZMEI-15, ZMEI-18, ZMEI-19, ZMEI-22, ZMEI-26, and ZMEI-14) demonstrated the ability to reduce the automaticity and contractility of isolated rat myocardial strips.
Introduction: Treatment of tuberculosis remains restricted to a limited number of drugs, and resistance to these agents continues to increase. The number of promising new drug candidates is currently low. Isoniazid, one of the first-line agents, has even been considered for replacement by moxifloxacin in initial therapy. Consequently, novel antimycobacterial compounds are urgently needed to expand the small repertoire of effective treatments for tuberculosis. Methods: We synthesized a series of novel dicarbonyl amide compounds built on a 1,4- dihydropyridine scaffold stabilized against oxidation through nitrogen substitution. Their antimycobacterial activity was evaluated to establish a new class of compounds related to isoniazid, which is a pyridine-based molecule with a hydrazide structure Results: Two dihydrazide compound series featuring varied aromatic substituents at the nitrogen atom and at the 4-position of the dihydropyridine ring showed limited activity. In contrast, the dicarbonyl amide series containing a monoalkyl residue demonstrated higher activity, particularly derivatives with a benzylamide substituent. Discussion: Compounds carrying a methoxy group at the 4-position of the 4-phenyl substituent, such as 6c, or on the phenyl ring attached to the nitrogen atom, as in 6e, showed the strongest activities. These effects were further surpassed by 7c, which contains an ethylamide residue Conclusion: We identified novel dicarbonyl amide compounds as promising antimycobacterial agents, with methoxy-substituted derivatives exhibiting superior activity. These compounds represent a new class of candidates for combating drug-resistant tuberculosis and may substantially expand the future pool of therapeutic agents.
Introduction: This study aims to elucidate the relationship between molecular structure and the physicochemical properties of triptan drugs used in migraine therapy through Quantitative Structure–Property Relationship (QSPR) analysis. In particular, it investigates the predictive performance of degree-based topological indices, including the recently introduced Elliptic Sombor index, for these properties. Methods: In this study, the molecular graphs of five triptan drugs, Sumatriptan, Rizatriptan, Naratriptan, Eletriptan, and Zolmitriptan, were constructed and analyzed. A custom MATLAB algorithm was developed to compute various degree-based topological indices for these structures. Subsequently, a comprehensive set of regression models, including linear, quadratic, cubic, and logarithmic functions, was employed using SPSS to establish quantitative correlations between the calculated indices and the experimental physicochemical properties of the drugs. Results: The analysis revealed significant correlations between the computed topological indices and key physicochemical properties, including boiling point, enthalpy of vaporization, flash point, molar refractivity, molar volume, and polarizability. Specifically, the Harmonic index exhibited the highest predictive accuracy for boiling point and thermal properties. For volumetric parameters such as molar refractivity, polarizability, and molar volume, the Sombor and Modified Sombor indices emerged as the most reliable predictors. Furthermore, the application of non-linear regression models, particularly quadratic and cubic functions, substantially enhanced prediction accuracy, yielding coefficients of determination (R2 ) approaching unity for several properties. Discussion: These findings confirm the efficacy of topological index-based QSPR models in predicting the physicochemical properties of anti-migraine agents. Such models offer a valuable computational tool for rational drug design, enabling the rapid screening of compounds and potentially accelerating the development pipeline by reducing reliance on costly experimental assays. However, given the limited sample size of this study, it is recommended that future research validate these predictive models on larger and more diverse datasets to ensure their broader applicability Conclusion: In conclusion, this study demonstrates the robust predictive capability of topological index-based QSPR models for estimating the physicochemical properties of triptan derivatives. By providing accurate theoretical predictions, this computational approach holds significant potential for optimizing rational drug design protocols, thereby contributing to substantial reductions in both the time and costs associated with experimental screening in pharmaceutical R&D.
Objective:: Although the antitumor activity of biguanide compounds in various types of tumors has been demonstrated, there is still a need to enhance their activity through further structural modifications. Methods: In this study, a series of 3-fluoromethoxy-containing biguanide derivatives with different branches was synthesized via intermediate derivatization. Their inhibitory effects on the growth of four bladder cancer cell lines were evaluated to assess the antitumor activities of these compounds. Western blotting experiments were performed to verify the underlying mechanisms. These antitumor effects were also determined in vivo. Results: A total of 10 novel fluorine-containing biguanide compounds with different branches were synthesized and characterized. The results of the MTT and colony formation assays revealed that most of the compounds had excellent antitumor activity, while 5b had the lowest IC50 value. Xenograft in vivo animal studies exhibited that 5b profoundly inhibited tumor growth with no observable toxicities. Both in vitro and in vivo mechanistic studies demonstrated that 5b inhibited tumor growth by down-regulating the p-EGFR signaling pathway. Discussion: Compound 5b, synthesized in this study, is of great significance for enhancing the antitumor activity of biguanides and clarifying its mechanism of action, but its selectivity, indepth verification of the mechanism of action, and comparison with existing drugs still need further study. Conclusion: Most fluorine-containing biguanide compounds with different branches exhibit excellent antitumor activity and low toxicity, with the most effective being 1-1,2-dimethylpropyl-5- (3-Trifluoromethoxyphenyl) biguanide. This finding provides new opportunities to improve the efficacy of biguanides and to develop potential anticancer drugs.
As the primary active constituent of the traditional Chinese medicinal herb Ligusticum chuanxiong, Tetramethylpyrazine (TMP) has demonstrated broad therapeutic potential across multiple disease areas. Its clinical applications span cardiovascular and cerebrovascular disorders, oncology, hepatorenal protection, and respiratory diseases. The mechanisms of action involve antiplatelet aggregation, anti-inflammatory, antioxidant, and anti-apoptotic effects, as well as modulation of autophagy and multiple signaling pathways. Despite its pleiotropic efficacy, the clinical utility of TMP is constrained by unfavorable pharmacokinetic properties, including rapid metabolism and limited oral bioavailability. To overcome these limitations, researchers have developed various TMP derivatives, which exhibit significantly improved metabolic stability and enhanced pharmacological activity. This review summarizes recent advances in TMP and its derivatives over the past five years, aiming to provide insights for the future development of novel TMP-based therapeutics.
Cancer and neurodegenerative disorders remain major public health challenges worldwide. Increasing incidence across age groups, together with persistently high mortality in many settings, contributes to substantial socioeconomic burdens on individuals, families, and healthcare systems. Histone Deacetylases (HDACs) are enzymes that remove acetyl groups from lysine residues on histone tails. As a key post-translational modification, histone deacetylation modulates chromatin organization and gene transcription. In many contexts, HDACmediated deacetylation is associated with increased chromatin compaction, which may limit transcription-factor accessibility and reduce transcriptional output. Beyond chromatin regulation, HDACs have been implicated in cell-cycle progression, apoptosis, inflammation, immune responses, redox homeostasis, and neuronal development. Given their involvement in disease mechanisms, Histone Deacetylase Inhibitors (HDACis) have attracted attention as potential epigenetic therapeutics with pleiotropic effects. By counteracting aberrant deacetylation, HDACis may help restore acetylation-dependent transcriptional programs and reactivate genes implicated in disease. They may also affect dysregulated signaling pathways and have been reported to exhibit antiproliferative, anti-inflammatory, neuroprotective, and anticancer effects. Accumulating preclinical and emerging clinical evidence suggests that HDACis are being evaluated for therapeutic activity in a range of malignant and neurodegenerative diseases. This review summarizes recent advances in HDACis, with emphasis on structural classification, key chemical features, molecular mechanisms, and clinical translation in oncology and neurodegeneration. By integrating these aspects, the article aims to provide a conceptual reference for targeted drug discovery and rational combination strategies for these challenging conditions.
Introduction: Staphylococcus aureus is the causative agent of mild to severe human infections. The exponential increase in resistance to available antibiotics has created the need to identify new drug targets and develop new drug candidates to combat bacterial infections. The PurS subunit of phosphoribosylformylglycinamidine synthase (synonym FGAM synthase) catalyzes the 4th step of the de novo purine biosynthesis in bacteria, including S. aureus. Purine nucleotides are essential in the bacterial life cycle and are required for growth and survival. Inhibition or disruption of FGAM synthase adversely affects the bacterial life cycle. Methods: This study reports cloning, expression, and purification (yield 16.08 mg/mL) of the PurS subunit of FGAM synthase from methicillin- and oxacillin-resistant Staphylococcus aureus, followed by interaction analysis of the PurS subunit with 50 US-FDAapproved drugs, using Saturation Transfer Difference (STD) NMR spectroscopy. Results: Among these drugs, tramadol HCl (1), nicotinamide (2), amoxicillin trihydrate (3), hydroxychloroquine sulphate (4), and phenylephrine HCl (5) showed interactions with the PurS subunit of FGAM synthase, using STD-NMR spectroscopy. All 50 drugs were also studied for their effects on thermal destabilization of the PurS subunit using differential scanning fluorimetry; among them, only nicotinamide (2) and drotaverine HCl (6) destabilized the PurS subunit of FGAM synthase. However, drug 6 interacted with the PurS subunit either irreversibly or with strong binding affinity, as no interactions in STD-NMR were observed. Therefore, drugs 1‒5, which showed interactions in STD-NMR, were further computationally studied, revealing comparable docking scores (-2.4 to 0.21) for complexes 1‒5 (PurS subunit, and drugs 1‒5), with substantial binding energies, supporting the experimental findings. Discussion: The current study focuses on FGAM synthase, a potential drug target in S. aureus. This is the first report on the identification of drugs that bind the PurS subunit of FGAM synthase using STD-NMR, DSF, and molecular docking. Drugs 1‒6 can be considered potential hits for further studies for drug discovery against infections caused by methicillin- and oxacillin-resistant S. aureus. Conclusion: These five hits merit further biochemical and mechanistic studies to validate their therapeutic potential against methicillin- and oxacillin-resistant S. aureus infections.
INTRODUCTION/OBJECTIVE:Breast cancer is the most common malignancy among women worldwide, and the emergence of resistance to anthracycline-based chemotherapy remains a major clinical challenge. Benzimidazole scaffolds have attracted considerable interest in medicinal chemistry due to their broad pharmacological properties and anticancer potential. This study aimed to investigate the anticancer activity, selectivity, and molecular mechanisms of novel nitro-benzimidazole derivatives in luminal and Adriamycin-resistant breast cancer cell lines. METHODS:A series of benzimidazole derivatives was synthesized and evaluated using in silico pharmacokinetic analyses. Cytotoxicity was assessed by MTT assay in MCF-7, adriamycinresistant MCF-7 (MCF-7/Adr), and normal human fibroblast cells CCD-1072sk. The most active compound was further investigated by RT-qPCR-based gene expression and pathway enrichment analyses, flow cytometry-based evaluation of apoptosis and cell cycle distribution, fluorescence-based morphological analyses, and gene-metabolite interaction analysis. RESULTS:Among the tested compounds, SN-1 exhibited the strongest antiproliferative activity, with IC₂⁽ values of 4.86 ± 0.27 μM in MCF-7 cells and 8.62 ± 1.51 μM in MCF-7/Adr cells, along with a high selectivity index. SN-1 significantly induced apoptosis and caused cell cycle arrest at the G2/M phase in MCF-7 cells and at the G0/G1 phase in MCF-7/Adr cells. Gene enrichment and metabolite interaction analyses revealed modulation of apoptosis-, cell cycle-, and metabolism-related pathways, including associations with glycerol, ATP, and ADP. DISCUSSION:These findings suggest that SN-1 exerts selective anticancer activity against both drug-sensitive and chemoresistant breast cancer cells through the regulation of apoptosis, cell cycle progression, and metabolic pathways. The observed effects on resistant cells further indicate the therapeutic potential of SN-1 in overcoming chemotherapy resistance. CONCLUSION:The nitro-benzimidazole derivative SN-1 exhibits strong and selective anticancer effects in both drug-sensitive and chemoresistant breast cancer cells by modulating apoptosis, cell cycle progression, and key metabolic pathways.
INTRODUCTION/OBJECTIVE:The main objective of this study is to test in silico the previously unexplored antimicrobial activity of the tetrapeptide tentoxin. To investigate its efficacy, in silico molecular docking was performed to analyze its interactions with key resistancerelated proteins, specifically FusB and the bacterial IMPDH, a validated target for antibiotic development. METHODS:Ligand preparation and quantum chemical analysis of tentoxin were performed using DFT at the CAM-B3LYP/TZVP level of theory. Molecular docking was executed via Auto- DockVina, while ADMET profiles were predicted using the Deep-PK platform. Protein-ligand interactions were characterized through computational visualization tools to assess binding modes and stability. RESULTS:For FusB, a binding energy of -9.1 kcal/mol with an inhibition constant of 0.213 μM was obtained. For bacterial IMPDH, a binding energy of -7.3 kcal/mol with an inhibition constant of 4.449 μM was obtained. DISCUSSION:These findings represent the first evidence of tentoxin's potential as a bacterial inhibitor. The strong binding to FusB and IMPDH suggests a specific mechanism of action, confirming that the compound effectively targets key bacterial proteins. CONCLUSION:These results provide a theoretical foundation for subsequent in vitro studies of tentoxin against a broad spectrum of bacteria, including multidrug-resistant strains. Our findings highlight the potential of natural fungal metabolites as a scaffold for developing novel antibacterial agents.
INTRODUCTION:The Coxsackie Adenovirus Receptor (CAR), encoded by the CXADR gene, facilitates entry of Coxsackie group B virus (CVB) and adenoviruses into host cells. Infections caused by CVB, particularly CVB3, are associated with severe complications, such as meningoencephalitis and cardiomyopathy. Currently, no specific antiviral therapy is available. This study aimed to identify novel lead compounds targeting CVB3 using an integrated in silico and in vitro approach. MATERIALS AND METHODS:A diversity-based High-Throughput Virtual Screening (HTVS) of a Zn-based natural compound library was conducted, followed by Molecular Dynamic Simulation (MDS) to assess binding stability. Top hits were evaluated using in vitro Micro Tissue Culture Antiviral Assays (MTCA), including Direct Pre-infection Incubation (DPI), Pre-Treatment Assay (PTA), and Viral Adsorption Assay (VAA) in HEp-2 cells. MTT assay was performed to assess cytotoxicity. RESULTS:Among the top five hits, ZN-002 [2-(3,4-dimethylphenyl) cyclohexa-2,5-diene-1,4- dione] showed strong binding affinity (< -5.0 kcal/mol) with stable interactions spanning residues Pro25 to Gln50 of the CAR protein. MDS confirmed binding stability over 100 ns. ZN- 002 demonstrated dose-dependent antiviral activity at 10-15 μM concentrations, effectively inhibiting 1, 10, and 100 TCID50 of CVB3 in multiple assay formats without cytotoxicity. DISCUSSION:ZN-002 interferes with the CAR-virus interaction interface, likely hindering viral entry into host cells. The compound's robust binding and broad antiviral efficacy across varying viral loads underscore its potential. The absence of cytotoxicity further supports its candidacy for therapeutic development. This dual in silico-in vitro validation platform accelerates earlystage antiviral discovery. CONCLUSION:ZN-002 represents a promising lead molecule against CVB3, warranting further evaluation through in vivo studies to explore its potential as a novel antiviral agent.
Following the publication of this article [1], it was noted that some chemical structures were misnumbered during processing of the text. This has now been corrected in the text and Table 5. The original article can be found online at: https://www.eurekaselect.com/article/144767
INTRODUCTION:The indole nucleus is considered a privileged pharmacophore in medicinal chemistry. Indole-2-carboxylic acid derivatives are valued for their antiproliferative and antibacterial properties, including the potential to overcome drug resistance. This study aimed to synthesize novel salicylidene hydrazones of indole-2-carboxylic acid and evaluate their potential as metallo-β-lactamase (NDM-1) inhibitors and antiproliferative agents alongside previously reported indole-2-carboxylic acid derivatives. METHODS:A novel series of salicylidene hydrazones of indole-2-carboxylic acid was synthesized with potential as metallo-β-lactamase inhibitors in mind. All compounds were evaluated for their inhibitory activity against NDM-1 and tested for antiproliferative potency against human chronic myelogenous leukemia K-562 cells and the multidrug-resistant (MDR) subline K- 562/4. Doxorubicin and previously reported indole derivatives (1, 5, 6) were used as reference compounds. RESULTS:Unlike the parent acid 1, the novel derivatives showed weak NDM-1 inhibition (IC50 > 50 μM). In contrast, salicylidene hydrazones 4a-g demonstrated strong antiproliferative activity (IC50 = 0.15-0.80 μM). This effect was particularly pronounced against the MDR subline K- 562/4. Notably, the IC50 values for several derivatives were up to 50-fold lower than that of doxorubicin against resistant cells. Hydrazide 3, hydrazones 4h and 4i, thiosemicarbazide 5, and hydroxamic acids 6a-c showed moderate antiproliferative activity (IC50 = 2.4-13.3 μM). DISCUSSION:The weak NDM-1 inhibition confirms that a free 2-carboxyl group is critical for binding within the enzyme's active site. However, converting this scaffold into salicylidene hydrazones significantly enhances antiproliferative potency. It also effectively enables the circumvention of P-glycoprotein (P-gp) mediated efflux in MDR leukemia cells. CONCLUSION:Indole-2-carboxylic acid salicylidene hydrazones emerged as promising scaffolds for developing new anticancer agents. They exhibit potent activity against leukemia cells, particularly against the P-gp-overexpressing MDR subline K-562/4.
BACKGROUND:Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are two cholinesterases that play important roles as therapeutic targets in the cholinergic system associated with neurodegenerative diseases such as Alzheimer's disease. OBJECTIVE:The purpose of this study was to assess the in vitro inhibitory potencies of 2- quinolinone derivatives against hAChE and hBuChE and to estimate the interaction types in silico. Besides, drug-likeness characteristics (ADME) and density functional theory (DFT) calculations of the compounds were used to support the in vitro inhibition studies. METHODS:IC50-[inhibitor] graphs and Lineweaver-Burk graphs were generated. Molecular docking studies were performed by AutoDock. While ADME properties were predicted by SwissADME, DFT calculations of the compounds were made by ORCA software. RESULTS:QU4 and QU6 were found to be the most effective inhibitors of AChE and BuChE with Ki values of 35.672±9.75 μM and 13.38±3.5 μM, respectively. The binding energy of QU3 against hAChE was estimated as -7.51 kcal/mol, while QU2 exhibited a binding energy of -9.11 kcal/mol against BuChE; these values are more negative than that of the reference inhibitor tacrine for both enzymes. Additionally, according to drug-likeness analysis, the derivatives except QU7 showed high blood-brain barrier permeability. DISCUSSION:The results suggest that QU4 and QU6 derivatives may have potential for cholinesterase inhibition. CONCLUSION:Overall, the findings of this study guide the development of more potent and selective inhibitors by appropriate structural modifications of the 2(1H)-quinolinone skeleton.
INTRODUCTION/OBJECTIVE:Haemonchosis is a gastrointestinal disease caused by the nematode Haemonchus contortus, a serious problem in sheep farming worldwide. Benzimidazole drugs are used as treatment; however, their ineffectiveness and resistant strains indicate a need for new therapeutic options. Therefore, this project aimed to determine the possible mode of action and nematicidal activity of secondary metabolites of the mushroom Pleurotus djamor against H. contortus. METHODS:Four pharmacological targets were selected to assess the binding affinity of the major secondary metabolites by molecular docking and molecular dynamics simulations. Subsequently, the nematicidal activity of selected compounds was evaluated using larval mortality assays. RESULTS:Molecular docking analysis determined an affinity of 5,6-dimethoxy-1(3H)-isobenzofuranone (DIB) and veratryl alcohol (VA) for phosphoethanolamine N-methyltransferase (PMT1 and PMT2). Nevertheless, molecular dynamics simulations revealed that only the PMT1-DIB complex displayed greater stability than the control. In the in vitro evaluation, VA induced dose-dependent larval mortality, reaching 55% at 5 mg/mL, while CAF was inactive. No synergistic effect was observed with the combination of VA and CAF. DISCUSSION:The stable interaction observed between DIB and PMT1 suggests that this enzyme may represent a promising anthelmintic target in H. contortus. In contrast, the biological activity exhibited by VA despite its unstable binding profile indicates the possible involvement of alternative molecular targets or pathways. Nevertheless, additional biochemical and experimental studies are required to further elucidate the underlying mechanisms of action. CONCLUSION:These findings highlight PMT1 as a promising pharmacological target and suggest that DIB and VA may contribute to the anthelmintic activity of P. djamor metabolites against H. contortus.
1,3,4-Thiadiazoles constitute an important heterocyclic scaffold with extensive antimicrobial potential. Owing to their unique physicochemical features, such as high lipophilicity, oral bioavailability, and stability in biological systems, this class of compounds has been widely exploited in antibacterial, antifungal, and agrochemical research. In this review, we comprehensively analyzed more than 100 synthetic 1,3,4-thiadiazole derivatives reported between 2007 and 2024, including hybrid molecules, metal complexes, and commercially used agents such as sulfamethizole, cefazolin, and bismerthiazol. Detailed comparison of these structures revealed that subtle changes in substitution patterns, particularly at the 2- and 5-positions of the thiadiazole ring, profoundly influence antimicrobial selectivity and potency. For example, electronwithdrawing groups (-Cl, -NO2) often enhanced Gram-positive activity, while lipophilic substituents improved antifungal efficacy against Candida and Aspergillus spp. Several compounds exhibited minimum inhibitory concentrations comparable to or superior to standard drugs such as Fluconazole, Ciprofloxacin, and Ampicillin, and many retained activity against multidrugresistant clinical isolates. In addition, derivatives targeting plant pathogens demonstrated superior control of Botrytis cinerea, Ralstonia solanacearum, and Rhizoctonia solani, highlighting the agricultural utility of this scaffold. Mechanistic investigations indicate diverse modes of action, including disruption of ergosterol biosynthesis, cell wall inhibition, efflux pump modulation, and interference with bacterial metabolic enzymes. Structure-based design, docking studies, and SAR analyses further underscore the versatility of the scaffold in guiding nextgeneration antimicrobial development. Collectively, this review consolidates structural and pharmacological insights into 1,3,4-thiadiazoles, underscoring their promise as adaptable scaffolds to address the.
INTRODUCTION/OBJECTIVE:Factor XIIa (FXIIa), a serine protease in the intrinsic coagulation pathway, is primarily involved in thrombosis rather than hemostasis, making it an attractive target for safer anticoagulants with reduced bleeding risk. We previously reported a series of potent and selective triazole-based FXIIa inhibitors. To further advance this class, we evaluated sixteen additional derivatives of the lead inhibitor (1). METHODS:FXIIa inhibition was assessed using a chromogenic substrate assay under physiological conditions. The new derivatives were structurally modified in two domains: the N1-benzoyl group and the C3-substituent. Kinetic characterization, selectivity profiling, and clotting assays were also performed. RESULTS:We identified three molecules inhibiting FXIIa with more than 40% at 100 μM. Structure- activity analysis revealed superior activity of a halogenated benzoyl group at the N1- position over a 3-phenylpropanoyl substituent and highlighted the importance of meta-position halogenation. A methyl ester at the 3-position of the triazole ring was required for activity, as analogs lacking this group were inactive. Inhibitor 6 was the most potent compound, exhibiting an IC₂⁽ of 56 nM and ~100% efficacy. It demonstrated a marginal-to-high selectivity of 4- 8,900-fold selectivity for FXIIa over thrombin, FXIa, FXa, FIXa, and plasmin. Kinetic analysis suggested active-site binding with a covalent mode of inhibition. In coagulation assays, inhibitor 6 prolonged both prothrombin time and activated partial thromboplastin time, with a greater effect on aPTT. DISCUSSION:These results define key structural determinants of FXIIa inhibition, including the importance of halogenated benzoyl substitution at N1 and a required methyl ester on the triazole scaffold. The high potency and selectivity of inhibitor 6 indicate effective engagement of the FXIIa active site with minimal off-target serine protease inhibition. Preferential prolongation of aPTT relative to PT is consistent with selective modulation of the intrinsic coagulation pathway. CONCLUSION:This study successfully identified a potent, selective, and covalent FXIIa inhibitor 6 and defined critical structure-activity relationships for the triazole-based chemotype. The findings validate the feasibility of developing FXIIa-targeted anticoagulants. Future work will focus on the rational design of next-generation inhibitors with enhanced potency and selectivity, further mechanistic studies, and in vivo profiling to advance therapeutic potential.
INTRODUCTION:Haemonchus contortus (H. contortus) is a gastrointestinal nematode that causes significant economic losses in sheep farming. The increasing resistance to conventional anthelmintics such as albendazole, levamisole, and ivermectin highlights the urgent need for new therapeutic agents. In this context, the present work reports, for the first time, the synthesis of 1,3-benzothiazin-4-ones with ovicidal activity against H. contortus. METHODS:Compounds 5a-d were synthesized via a one-pot reaction between 1-(2-aminoethyl) pyrrolidine 1, substituted arylaldehydes 2 (4-CH3 2a, 2-NO2 2b, 4-NO2 2c, 4-OCH3 2d), and thiosalicylic acid 3. Structural characterization was confirmed by ¹H and 13C NMR spectroscopy and GC-MS analysis. Anthelmintic activity was assessed through H. contortus egg-hatching inhibition assays. All compounds exhibited measurable inhibitory effects, at least at the highest concentrations tested (40, 20, 10, 5, 2.5, and 1.25 μg·mL⁸¹). RESULTS:These compounds were obtained in moderate yields (31-54%), and their structures were confirmed by GC-MS and 1D/2D NMR data. Formation of the benzothiazinone ring was supported by the characteristic H2 and C2 signals (δ 5.93-6.08 and 61.6-62.3 ppm), along with the lactam carbonyl resonance at δ 163.7-164.1 ppm. DISCUSSION:Four novel 1,3-benzothiazin-4-ones (5a-d) were synthesized via a threecomponent one-pot reaction in moderate yields. The electronic and positional effects of the aryl substituents may influence the ovicidal activity against H. contortus, although these hypotheses require experimental validation in future mechanistic studies. All molecules displayed activity at concentrations lower than those required for the reference drug, thiabendazole (20 μg·mL⁸¹; 99.103 μM). CONCLUSION:The results indicate that these benzothiazinone derivatives represent promising scaffolds for the development of new anthelmintic candidates. Compound 5c - 2-(2- nitrophenyl)-3-[2-(pyrrolidin-1-yl)ethyl]-2,3-dihydro-4H-1,3-benzothiazine-4-one - exhibited the highest activity at 40 μg·mL⁸¹ (104.3 μM), inhibiting egg hatching by 39-45%.
