Current Issue : July-September Volume : 2025 Issue Number : 3 Articles : 5 Articles
Methicillin-resistant Staphylococcus aureus is a serious problem in healthcare due to its lethal severe infections and resistance to most antimicrobial agents. The number of new approved antimicrobial agents is declining, and combined with the spread of drug-resistant bacteria, it is predicted that effective antimicrobial agents against multidrugresistant bacteria will be exhausted. We conducted in silico and in vitro discovery of novel antimicrobial small molecules targeting the SaMurB enzyme involved in cell wall synthesis in Staphylococcus aureus (S. aureus). We performed hierarchical structure-based drug screenings to identify compounds and their analogues using a library of approximately 1.3 million compound structures. In vitro experiments with Staphylococcus epidermidis (S. epidermidis) identified three compounds (SH5, SHa6, and SHa13) that exhibit antibacterial activity. These three compounds do not have toxicity against human-derived cells. SHa13 exhibited remarkable activity (IC50 value =1.64 ± 0.01 μM). The active compound was predicted to bind to the active site of SaMurB by forming a hydrogen bond with Arg188 in both R and S bodies. These data provide a starting point for the development of novel cell wall synthesis inhibitors as antimicrobial agents targeting SaMurB....
Background/Objectives: Microcolins A–M are cytotoxic marine lipopeptides produced by the cyanobacterium Moorena producens, also known as Lyngbya majuscula. Recent studies have shown that two compounds in the series, microcolins B and H, can form covalent complexes with phosphatidylinositol transfer proteins α and β (PITPα/β) upon the reaction of their α,β-unsaturated ketone group with the thiol group of a key cysteine residue of PITP. These observations prompted us to compare the binding of all microcolins and a few related derivatives (VT01454 and (deoxy)majusculamide D) to PITP to delineate structure–binding relationships. Methods: A molecular docking analysis led to the identification of microcolin E as the potentially best PITPα binder in the series, followed by microcolins B and H and analog VT01454. The computational data agree well with the published experimental results. Results: The binding of microcolin H into a large cavity of PITPα positions its reactive electrophilic α,β-unsaturated ketone close to the thiol of Cys95, enabling the facile formation of a covalent C-S linkage. A similar bonding can occur with the Cys94 of PITPβ. Molecular models of microcolins bound to PITP were compared to identify structural elements chiefly implicated in the recognition process. Conclusions: This computational study provides guidance in the design of microcolin derivatives targeting PITPα/β considered targets for cancer and inflammatory pathologies....
The world today is being ravaged by the emergence and re-emergence of microbial infections caused by antimicrobial-resistant strains, brought about primarily by the frequent and perhaps unnecessary use of antimicrobial agents. A need therefore arises to develop new antimicrobial drugs that can combat these pathogens resistant to currently available antibiotics. This present study has adopted a multi-enzyme in silico approach in evaluating new 2-pyrazolines as antimicrobial agents, targeting and aiming to inhibit three pivotal enzymes in the bacteria’s life cycle. A library of 2-pyrazolines was tailored to achieve the desired activity. The library of compounds and amoxicillin, a standard antimicrobial drug, were docked into the molecular target enzymes. They were also subjected to toxicity and drug-likeness tests, using PROTOX and swissADME, respectively. A moderate toxicity profile was indicated, as more than 90% of the ligands were in ProTox class 4. The majority exhibited advantageous ADME characteristics. A significant number of them demonstrated a binding affinity for the target proteins that was stronger than both the native ligand and the binding affinity of amoxicillin. Ligands 30, 20, and 8 are the notable ones across all target enzymes. These results suggest that these novel ligands may be powerful inhibitors, particularly when it comes to interfering with the formation of bacterial cell walls, folic acid, and nucleotide metabolism. Additional in vivo and in vitro research is required to confirm these results and evaluate their therapeutic potential....
Glycogen synthase kinase-3 beta (GSK-3β) plays a crucial role in multiple cellular processes and is implicated in different types of cancers and neurological disorders, including Alzheimer’s disease. Despite extensive efforts to develop novel GSK-3β inhibitors, the discovery of potent and selective lead compounds remains a challenge. In this study, we evaluated the GSK-3β inhibitory potential of semisynthetic flavonoid derivatives, which exhibited sub-micromolar activity. To gain further insights, we employed molecular docking, molecular dynamics simulations, and pharmacokinetic profile predictions. The docking studies revealed that the most potent inhibitor, compound 10, establishes key interactions with the ATP-binding site. Molecular dynamics simulations further confirmed that compound 10 maintains stable interactions with GSK-3β throughout the simulation. Additionally, pharmacokinetic predictions identified compound 3 as a promising candidate for Alzheimer’s disease therapy due to its ability to cross the blood–brain barrier. These findings suggest that, within the studied flavonoid derivatives, these compounds (particularly 10 and 3) hold potential as lead compounds for GSK-3β inhibition. The combination of strong enzymatic inhibition, stable binding interactions, and favorable pharmacokinetic properties highlights their promise for further development in cancer and neurodegenerative disease research....
Synthetic cannabinoids (SCs), a class of widely abused new psychoactive substances, are characterized by their structural diversity and rapid evolution. Structure– affinity relationships are crucial for predicting pharmacological effects and potential toxicity. Traditional methods for affinity testing are often complex and less applicable to newly modified compounds. In contrast, Surface Plasmon Resonance (SPR) is a sensitive and label-free technology that detects molecular interactions by measuring refractive index changes on a metallic surface with the advantages of high sensitivity, low sample consumption, and high-throughput capability. In this study, we used SPR to determine the receptor affinity constants of 10 SCs, including some first-reported substances, and analyzed their structure–affinity relationships to validate the method’s reliability. The results showed that (1) indazole-based SCs exhibited stronger CB1 receptor affinity compared to their indole counterparts, (2) the head structure of p-fluorophenyl enhanced affinity relative to 5-fluoropentyl, (3) and the affinity rankings obtained from SPR experiments were consistent with those derived from traditional methods. These results collectively demonstrate the reliability and effectiveness of SPR in assessing CB1 receptor affinity and differentiating affinity differences among structurally similar analogs, with promising application prospects in drug research, particularly in the development and screening of therapeutic agents targeting cannabinoid receptors....
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