Search Results (530)

The creation of new potential metal-based therapeutics largely relies on the development of useful ligand scaffolds. In recent years, our research group has introduced thiophosphoryl-functionalized carboxamides as a convenient framework for obtaining biologically active cyclopalladated derivatives. In continuation of these studies, β-(aminoalkyl)phosphine sulfides bearing additional substituents in the ethylene backbone were synthesized for the first time and reacted with picolinic acid to afford a series of new functionalized amide ligands. The latter readily underwent direct cyclopalladation under the action of PdCl₂(NCPh)₂ under mild reaction conditions. The resulting S,N,N-complexes were studied for in vitro cytotoxicity against several solid and hematopoietic cancer cell lines, as well apoptosis induction and DNA damage ability, which showed their promising anticancer properties. In addition, moderate antibacterial activity was observed for a representative palladocycle of the β-thiophosphorylated derivatives. Full article

Glucose deprivation is a major metabolic stress that requires coordinated adaptive responses to maintain cellular homeostasis and survival, yet the role of tripartite motif-containing 24 (TRIM24) in this process remains unclear. To address this question, we generated CRISPR-Cas9-mediated TRIM24-knockout MCF-7 and HEK293 cell lines, performed targeted metabolomic profiling and aspartate assays, used 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR), aminooxyacetic acid (AOA), aspartate supplementation, and glutamic-oxaloacetic transaminase 2 (GOT2) knockdown to probe AMPK signaling and aspartate metabolism, and examined starvation responses in constitutive Trim24 knockout mice on a C57BL/6 background. Loss of TRIM24 sensitized cells to glucose deprivation. Re-expression of TRIM24 partially restored cell viability under glucose deprivation in both MCF-7 and HEK293 cells. Under glucose-free conditions, TRIM24 deficiency was associated with impaired AMP-activated protein kinase (AMPK) pathway activation, increased intracellular aspartate accumulation, and altered ATP/AMP levels. Pharmacological reactivation of AMPK by AICAR improved the survival of TRIM24-deficient cells under glucose deprivation. Reducing intracellular aspartate by AOA treatment or GOT2 knockdown restored AMPK pathway activation and improved adaptation to glucose deprivation, whereas exogenous aspartate suppressed AMPK signaling and increased ATP/AMP levels. In vivo, starvation of Trim24-deficient mice was associated with reduced AMPK pathway activation and increased aspartate levels. Together, these findings support a model in which TRIM24 contributes to adaptation to glucose deprivation and in which abnormal aspartate accumulation contributes to impaired AMPK pathway activation in TRIM24-deficient cells. Full article

Objectives: Multidrug-resistant (MDR) Pseudomonas aeruginosa represents a major clinical challenge, driven in part by resistance–nodulation–division (RND) efflux pumps that reduce intracellular antibiotic concentrations and limit the efficacy of many antibacterial agents, including fluoroquinolones. The aim of this study was to identify and characterize TXA11114 as a small-molecule efflux pump inhibitor (EPI) capable of restoring the activity of the fluoroquinolone levofloxacin against MDR P. aeruginosa. Methods: The antibacterial activity of the TXA11114–levofloxacin combination was evaluated using minimum inhibitory concentration (MIC) assays against panels of clinical isolates. Mechanistic studies included levofloxacin accumulation assays, ethidium bromide accumulation assays, outer-membrane permeability measurements, and whole-genome sequencing of mutants with altered potentiation phenotypes. In vivo efficacy was evaluated in murine thigh and lung infection models, while preliminary safety and drug-like properties were assessed using cytotoxicity assays and in vitro ADME profiling. Results: The TXA11114–levofloxacin combination produced > 1 log₁₀ CFU reductions in bacterial burden in murine thigh and lung infection models, exceeding the activity of levofloxacin monotherapy. TXA11114 markedly potentiated levofloxacin activity, producing substantial reductions in levofloxacin MIC values across multiple MDR clinical isolates, and also enhanced the activity of several additional efflux pump substrates, including β-lactams, tetracyclines, chloramphenicol, and trimethoprim–sulfamethoxazole. Mechanistic experiments demonstrated increased intracellular accumulation of efflux substrates without evidence of nonspecific membrane disruption, and mutations in ompH were associated with altered potentiation phenotypes. Conclusions: The TXA11114–levofloxacin combination produced significantly greater bacterial reductions than levofloxacin monotherapy in murine infection models. Levofloxacin was selected because fluoroquinolone resistance in P. aeruginosa is frequently driven by efflux-mediated mechanisms. While this study focused on levofloxacin potentiation, future work will evaluate additional efflux pump substrates and further define the molecular target of TXA11114. Full article

1,3-Thiazole derivatives are of interest in pharmacy, medicine, and agriculture as potential biologically active substances. We have proposed for the first time a convenient and effective method for the synthesis of amidoalkylated derivatives of 2-amino-1,3-thiazole. This approach is based on the reaction of amidoalkylated thioureas with α-halocarbonyl compounds. The reaction was carried out under stirring at 20 °C in ethanol with the addition of an equimolar amount of triethylamine to bind the released hydrogen halide. The yield of the obtained 1,3-thiazole derivatives was 68–75%. An attempt to carry out a counter-synthesis by amidoalkylation of the corresponding 2-amino-1,3-thiazole derivative was unsuccessful due to strong resinification of the reaction mass. The structure of the compounds obtained was confirmed by ¹H and ¹³C NMR spectroscopy. The structure was finally confirmed by X-ray structural analysis performed for N-(2,2,2-trichloro-1-((4-phenylthiazol-2-yl)amino)ethyl)acetamide. Full article

A novel series of benzothiazole scaffolds were presented to test their in vitro α-amylase and α-glucosidase activities for combating diabetes mellitus, which is one of the most rapidly growing diseases. The tested compounds were elucidated structurally by various spectroscopic techniques like ¹H NMR, ¹³C NMR and HRMS. All compounds exhibited a varied range of inhibitory activities against targeted α-amylase and α-glucosidase enzymes, with IC₅₀ values of 1.58 ± 1.20 to 7.54 ± 3.60 µM (α-amylase) and 2.10 ± 1.10 to 8.90 ± 4.10 (α-glucosidase), respectively. The obtained results were compared with the standard acarbose drug, with IC₅₀ values of 0.91 ± 0.20 µM (α-amylase) and 1.80 ± 1.10 µM (α-glucosidase). Specifically, methyl 2-amino-4-((6-methoxypyridin-3-yl)methoxy)benzo[d]thiazole-6-carboxylate (5c) and methyl 4-((6-methoxypyridin-3-yl)methoxy)-2-(thiazole-2-carboxamido)benzo[d]thiazole-6-carboxylate (6b) emerged as potent inhibitors of α-amylase and α-glucosidase enzymes. These potent compounds were further screened for in silico molecular docking studies to investigate possible binding interactions with active sites of targeted enzymes, and results obtained demonstrated that potent compounds exhibited stronger binding affinities toward anti-diabetic enzymes compared to the positive control acarbose. Full article

Cancer remains the second leading cause of death worldwide, highlighting the urgent need for novel therapeutic agents. In this work, twenty derivatives of N-benzyl-6-chloro-4-hydroxy-2-quinolone-3-carboxamides were synthesized and spectroscopically analyzed using FT-IR, NMR (¹H and ¹³C), and elemental analysis. Substitution of benzyl moiety with o-CH₃ (8), p-OCH₃ (10), m-CH₃ (18), p-CH₃ (19), and p-CF₃ (21) demonstrated three-fold distinct cytotoxicity against human colon cancer (HCT-116) cells with IC_50s of 72.0, 100.0–112.0 µM. The cheminformatics calculations disclosed that the analogues possess diverse physicochemical properties and invariable predictions across six drug-likeness scoring models, supporting their potential cytotoxicity profile against colorectal cancer cell lines (Caco-2 and HCT-116). The docking studies against both wild-type and mutant PI3Kα clarified binding interactions, implying that particular functionalities improve efficacy and selectivity. This study provides further evidence for the therapeutic promise of quinolones in targeting cancer-specific pathways and expedites the process for developing potent anticancer agents. Full article

Background/Objectives: Pyrazole carboxamides are widely used as adaptable medicinal-chemistry scaffolds and have been explored as cholinesterase (ChE) inhibitor chemotypes. In this work, we prepared a new series of 4-arylazo-3,5-diamino-N-tosyl-1H-pyrazole-1-carboxamides 5(a–m) and evaluated their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), supported by structure-based computational analyses. Methods: Thirteen derivatives 5(a–m) were synthesized, fully characterized with analytical techniques (FT-IR, H NMR, and C NMR), and tested in vitro against AChE and BChE, with tacrine (THA) used as the reference inhibitor. Docking calculations were used to examine plausible binding modes. The top-ranked complexes (7XN1–5e and 4BDS–5i) were further examined by 100 ns explicit-solvent molecular dynamics (MD) simulations in Cresset Flare, followed by RMSD/RMSF analysis and contact-persistence profiling. Predicted ADME/Tox. properties were also assessed to identify potential developability issues. Results: The series showed strong ChE inhibition, and several compounds were more potent than THA. Compound 5e (4-nitro) was the most active AChE inhibitor (K_I = 20.86 ± 1.61 nM) compared with THA (K_I = 164.40 ± 20.84 nM). For BChE, the K_I values ranged from 31.21 to 87.07 nM and exceeded the reference compound’s activity. MD trajectories supported stable binding in both systems (10–100 ns mean backbone RMSD: 2.21 ± 0.17 Å for 7XN1–5e; 1.89 ± 0.11 Å for 4BDS–5i). Most fluctuations were confined to flexible regions, while key contacts remained in place, consistent with the docking models. ADME/Tox. predictions suggested moderate lipophilicity but generally low aqueous solubility; all compounds were predicted as non-BBB permeant, and selected liabilities were flagged (e.g., carcinogenicity for 5e/5g/5h/5i; nephrotoxicity for 5f/5g). Conclusions: The 4-arylazo-3,5-diamino-N-tosyl-1H-pyrazole-1-carboxamide scaffold delivers low-nanomolar ChE inhibition, with docking and MD supporting stable binding modes. Future optimization should prioritize solubility improvement and mitigation of predicted toxicities and metabolic liabilities, especially given the predicted lack of BBB permeability for CNS-directed applications. Full article

Background: Silver(I) complexes with aromatic heterocyclic ligands are well known for their broad antimicrobial potential, largely attributed to their ability to interact with biomolecular targets. Results and Discussion: In this study, a new polynuclear silver(I) complex with N-(3′-phenylpropyl)quinoxaline-2-carboxamide (pqx-2ca), [Ag(NO₃)(pqx-2ca)]_n, was synthesized. Its structure was confirmed by single-crystal X-ray diffraction and comprehensively characterized using NMR, IR, and UV–Vis spectroscopy, while its behavior in solution was further elucidated through density functional theory (DFT) calculations combined with spectral simulations. The complex demonstrated significantly enhanced antimycobacterial activity compared with the free ligand when tested against the avirulent Mycobacterium tuberculosis H37Ra, fast-growing model organisms M. smegmatis and M. aurum, as well as the nontuberculous species M. avium and M. kansasii. Experimental and docking studies confirmed stable binding of the complex to subdomain III of bovine serum albumin (BSA) and to the minor groove of DNA. Furthermore, docking to validated mycobacterial targets revealed inhibitory potential toward the InhA and MmpL3 proteins, with binding affinities comparable to those of standard inhibitors. Conclusions: These results highlight [Ag(NO₃)(pqx-2ca)]_n as a promising candidate for the development of silver-based antimycobacterial agents with a dual mechanism of action involving both DNA and protein targets. Full article

Background: Among the 15 human (h) carbonic anhydrase (CA; EC 4.2.1.1) isoforms, hCA IX and XII are particularly important due to their roles in tumor cell growth and survival, identifying them as promising targets for anticancer therapy. As a result, considerable effort has been directed toward the development of novel inhibitors that are highly selective for these isoforms. Methods: A library of twelve novel N-aryl-2-(4-sulfamoylphenyl)hydrazine-1-carbothioamides 3 along with two new N-aryl-2-(4-sulfamoylphenyl)hydrazine-1-carboxamide derivatives 5 were synthesized and their inhibition abilities were tested against four human carbonic anhydrase isozymes (hCA I, II, IX and XII) related to some global diseases including glaucoma, cancer and osteoporosis. Results: All compounds exhibited potent inhibition of the tested isoforms in the nanomolar range. Compound 3i showed the highest inhibition of hCA I activity but demonstrated poor selectivity toward the other isoforms. Compound 3h displayed superior selectivity for hCA II over hCA I (hCA I/II = 37) and exhibited 2.5-fold higher inhibitory activity compared to acetazolamide (AAZ). Among the tested compounds, 3l (K_i = 32.1 nM) demonstrated markedly improved selectivity for hCA IX over hCA I, II, and XII relative to the standard drug. Notably, compound 3a showed the most potent inhibition against hCA XII (K_i = 6.8 nM), comparable to AAZ, while exhibiting significantly greater selectivity over off-target isoforms and the other tumor-associated isozyme (hCA IX/XII = 20 versus hCA IX/XII = 4.5 for AAZ). Conclusions: The present study suggests potent lead compounds as selective hCA IX and XII inhibitors with anticancer activity. Full article

This work describes the lead optimization of a promising class of antibacterial compounds, derived from a previously reported N-[4-(4-fluorophenoxy)phenyl]-6-(methylsulfonyl)-2,6-diazaspiro [3.4]octane-8-carboxamide (LK1819), through systematic scaffold simplification. A novel series of amide derivatives were designed and synthesized, exploring key structural variations, including the replacement of the diphenyl ether core with a biphenyl system. All compounds were evaluated for in vitro antibacterial activity against the ESKAPE panel of pathogens. The most potent simplified analogs demonstrated exceptional, broad-spectrum activity, with minimum inhibitory concentrations (MICs) that were 10 to 100 times lower than the control antibiotic ciprofloxacin against many strains. Mechanistic studies using a reporter system and enzymatic assays revealed that the compounds do not inhibit protein synthesis but disrupt DNA replication, exhibiting a dose-dependent inhibitory effect on bacterial topoisomerase I and DNA gyrase. The compounds showed moderate toxicity against human cell lines, consistent with their DNA-targeting mechanism, but cytotoxicity assays indicated a sufficient selectivity window. We conclude that scaffold simplification successfully yielded highly potent antibacterial agents with a defined mechanism of action, presenting a promising foundation for further development as antibiotics and potentially as anticancer agents. Full article

Background: Hypoxia-inducible factor-1α (HIF-1α) is a well-known transcriptional regulator that mediates a broad spectrum of cellular responses to hypoxia, including angiogenesis, extracellular matrix remodeling, and metabolic reprogramming. These activities can be achieved by upregulation of numerous genes, such as vascular endothelial growth factors, fibroblast growth factors, and platelet-derived growth factors, which are involved in the growth regulation of normal tissues and solid tumors. Notably, HIF-1α-mediated regulation of the solid tumor’s microenvironment effectively modulates tumor sensitivity to anticancer therapies and thereby can contribute to disease progression. Methods: The study was performed on breast, lung and prostate cancer cell lines. Protein expression was examined by western blotting. Antitumor activity of 2-ANPC was measured by syngeneic 4T1 breast cancer mouse model. Results: We show here that a 2-aminopyrrole derivative (2-amino-1-benzamido-5-(2-(naphthalene-2-yl)-2-oxoethylidene)-4-oxo-4,5-dihydro-1-H-pyrrole-3-carboxamide—2-ANPC), previously shown as a potent microtubule-targeting agent, effectively downregulates HIF-1α expression in a broad spectrum of cancer cell lines, including breast, lung, and prostate cancer. The downregulation of HIF-1α expression in 2-ANPC-treated cancer cells was due to enhanced proteasome-mediated degradation, whereas the proteasome inhibitor MG-132 effectively reversed this downregulation. 2-ANPC’s potency in downregulating HIF-1α was also shown in vivo by using the 4T1 breast cancer syngraft model. Importantly, this 2-aminopyrrole derivative also downregulated the expression of vascular endothelial growth factor receptors 1 and 3 (VEGFR1 and 3) in 4T1 tumors, which correlated with decreased tumor weight and size. As expected, an increase in apoptotic (i.e., cleaved caspase-3-positive) cells was detected in 4T1 tumors treated with 2-aminopyrrole derivative. Lastly, using various computational tools, we identified four potential binding sites for 2-ANPC to interact with HIF-1α, HIF-1β, and the p300 complex. Conclusions: Collectively, we show here, for the first time, that HIF-1α is a novel molecular target for the 2-aminopyrrole derivative (2-ANPC), thereby illustrating it as a potential scaffold for the development of potent chemotherapeutic agents with anti-angiogenic activity. Full article

Organic monosubstituted hydrazine derivatives (Ar-NHNH₂, RC(O)-NHNH₂, Alkyl-NHNH₂) are synthetically available, atom-efficient and stable sources of C-centered radicals upon oxidation with extrusion of the energetically favorable N₂ molecule. This review summarizes the synthetic application of monosubstituted hydrazine derivatives (arylhydrazines, carbazates, acylhydrazides, hydrazine carboxamides and alkylhydrazines) in free-radical C-C bond-forming reactions. The main application directions in this field are (a) alkene difunctionalization, (b) cascade cyclization initiated by the addition of hydrazine-derived C-centered radicals to acrylamides and isonitriles, and (c) CH-functionalization of (hetero)arenes via C-centered radical addition followed by oxidative dehydrogenation (re-aromatization). Full article

A series of dimethylpyridine-3-carboxamide derivatives was designed as potential, selective, non-zinc chelating inhibitors of matrix metalloproteinase 13 (MMP-13), and subsequently synthesized. The identity of the obtained compounds was confirmed by FT-IR, ¹H/¹³C NMR, and HR-MS methods. Fluorescence spectroscopy was applied to study the interaction of synthesized compounds with human serum albumin, providing insight into their potential transport properties in plasma. In parallel, the electronic properties and reactivity parameters relevant to enzyme binding of the designed molecules were analyzed using density functional theory. Molecular docking and molecular dynamics simulations revealed the compounds to interact preferentially and stably within the S₁ pocket of MMP-13 via hydrogen bonds and π-stacking interactions. The calculated binding free energy confirmed the stability and persistence of the complexes during simulation, indicating a strong and specific recognition pattern. On the other hand, their affinity towards MMP-8 was considerably weaker, which is consistent with the predicted selectivity profile. In addition, the biological evaluation confirmed MMP-13 inhibition. Finally, in vitro tests revealed their cytotoxic activity against cancer cell lines. Full article

Background/Objectives: Direct-acting antivirals vary by lineage and face rapid resistance. We identified the oxazole-4-carboxamide lead KB-2777 and aimed to define its in vitro activity across α/β-coronaviruses, time-of-addition (TOA) profile, host-response signatures, and combinability with benchmark DAAs. Methods: We tested KB-2777 (≤25 μM) against HCoV-NL63 (LLC-MK2), HCoV-OC43 (Vero E6; MRC-5 for transcript profiling), and PEDV (Vero E6). We quantified extracellular viral RNA by RT-qPCR at 72 h (n = 3) and confirmed activity by spike-protein immunofluorescence (IFA), cytopathic effect (CPE) protection, and TCID₅₀. We compared TOA regimens (full, pre, co, post), evaluated combinations with nirmatrelvir (NL63) or GS-441524 (OC43) using ZIP scores, and profiled infection-context transcripts (IL6, IFNB1, ISG15, NRF2/antioxidant, UPR). Results: KB-2777 reduced viral RNA with EC₅₀ 5.27 μM (NL63), 1.83 μM (OC43), and 1.59 μM (PEDV) without cytotoxicity in the tested range. In NL63 post-treatment, inhibition was minimal at 24 h but clear at 48–72 h (EC₅₀ 2.42 μM at 48 h; 5.25 μM at 72 h). TCID₅₀ decreased at 48 h (12.5–25 μM, n = 3, p < 0.0001), and IFA/CPE corroborated antiviral activity. TOA ranked full > pre ≈ post > co. Combinations were additive to synergistic (ZIP 5.16 with nirmatrelvir; 8.40 with GS-441524). In OC43-infected MRC-5 cells, KB-2777 attenuated IL6, IFNB1, ISG15, and selected UPR transcripts, with limited changes in uninfected cells (n = 3). Conclusions: KB-2777 shows reproducible cell-based anti-coronavirus activity across α/β lineages, a TOA signature consistent with early post-entry host modulation, and favorable, non-antagonistic combinability with DAAs. These findings support target deconvolution, SAR/ADME optimization, and evaluation in primary airway and in vivo models. Full article

Cell surface sialylation is utilized by a number of pathogenic bacteria to evade the host immune system through molecular mimicry of host sialoglycoconjugates. Human pathogen Neisseria meningitidis serotype B (NmB) expresses both sialylated capsule and surface lipooligosaccharides as pivotal virulence factors. An essential enzyme in the sialylation pathway of NmB is CMP-sialic acid synthetase (CSS), which produces the activated nucleotide sugar necessary for sialic acid transfer. In this work, novel C-4, -5, -7, and -9 functionalized derivatives of neuraminic acid β-methyl glycoside (Neuβ2Me) were synthesized as candidate CSS inhibitors. A number of these were found to reduce the activity of NmB CSS in vitro. The highest inhibition of NmB CSS, in a mixed mode manner, was observed with a Neu5Acβ2Me C-9 serine carboxamide. Direct interaction with the enzyme was confirmed by Saturation Transfer Difference (STD) NMR. Supplementation of growth media with this compound reduced lipooligosaccharide (LOS) sialylation of living N. meningitidis, thus providing an interesting starting point for the development of specific NmB CSS inhibitors as an alternative treatment strategy to fight bacterial infections. Full article