Search Results (3)

The venom of the Asian hornet (Vespa affinis) comprises a complex mixture of biologically active substances, including various enzymes such as phospholipase A and hyaluronidase; amines such as histamine, serotonin, and catecholamines; peptides such as mastoparan and vespakinin; and other components including acetylcholine and antigen 5. This complexity reflects the highly evolved nature of V. affinis as a venomous insect. The composition of animal venoms often exhibits a certain degree of variability, making the study of biogenic amines particularly intriguing. The objective of this research was to confirm and identify the presence of tetradecylamine in the venom of Vespa affinis using the scientific computational analysis software MetFrag. In addition, the study aimed to construct the biosynthetic pathway of this compound and to predict its potential biological roles. The predicted biosynthetic route of tetradecylamine suggested its possible involvement in antibacterial activity. Antibacterial assays were performed against four bacterial strains Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Klebsiella pneumoniae. The results revealed that tetradecylamine exhibited notable inhibitory effects, with minimum inhibitory concentration (MIC) values of 2, 4, 8, and 4 µg/mL, and minimum bactericidal concentration (MBC) values of 2, 4, 8, and 4 µg/mL, respectively. Furthermore, molecular docking studies were conducted using penicillin-binding protein 2x (PBP2x, PDB ID: 5OIZ) as the target protein. Among eight tested ligands, streptomycin exhibited the highest binding affinity with a docking score of 64.76. In contrast, biogenic amines such as 2-phenylethylamine and tetradecylamine showed docking scores of 33.74 and 48.2, respectively. In the MurA protein (PDB ID: 3VCY), the biogenic amine ligand tetradecylamine exhibited a binding affinity comparable to that of certain reference drugs. Specifically, tetradecylamine achieved a GOLD score of 52.58, whereas ampicillin showed a higher score of 61.53. Notably, tetradecylamine demonstrated a higher binding affinity to the target protein compared with certain conventional antibiotics such as doxycycline and gentamycin. Full article

The growing emergence of multidrug-resistant bacterial pathogens drives the need for new antibacterial agents. Punicalagin exhibits efficacy against methicillin-resistant Staphylococcus aureus (MRSA), but its specific antibacterial mechanisms remain unclear. This study unveiled the specific antibacterial mechanism of punicalagin against MRSA via phenotypic and transcriptomic analyses. Punicalagin was found to induce severe cell wall damage and membrane disruption. Competitive binding assays identified lipoteichoic acid (LTA) as a potential target, and transcriptomic analysis further revealed that punicalagin downregulated key genes involved in cell wall synthesis (murA, murE) and LTA biosynthesis (dltA-D), consistent with the disruption of the cell wall. Additionally, punicalagin disrupted membrane homeostasis by inhibiting fatty acid synthesis (fabD, fabZ) and amino acid metabolism (dapA, dapB), leading to increased membrane permeability, which aligned with the phenotypic manifestations of membrane damage. Collectively, this work links phenotypic changes to specific gene expression patterns, unveiling that punicalagin inactivates MRSA via the multi-pathway regulation of the cell wall (LTA) and membrane function—providing insights for combating antibiotic-resistant pathogens in food safety and clinical settings. Full article

Enzymes MurA and MurF, involved in bacterial cell wall synthesis, have been validated as targets for the discovery of novel antibiotics. A panel of plant-origin antibacterial diterpenes and synthetic analogs derived therefrom were investigated for their inhibitory properties on these enzymes from Escherichia coli and Staphylococcus aureus. Six compounds were proven to be effective for inhibiting MurA from both bacteria, with IC₅₀ values ranging from 1.1 to 25.1 µM. To further mechanistically investigate the nature of binding and to explain the activity, these compounds were docked into the active site of MurA from E. coli. The aromatic ring of the active compounds showed a T-shaped π–π interaction with the phenyl ring of Phe328, and at least one hydrogen bond was formed between the hydroxy groups and Arg120 and/or Arg91. The results disclosed here establish new chemical scaffolds for the development of novel entities targeting MurA as potential antibiotics to combat the threat of pathogenic bacteria, particularly resistant strains. Full article