Takehara M, Homma Y, Ishihara T, Sakaguchi Y, Kasai Y, Matsumoto K, Nakashima K, Yamaji T, Tanaka Y, Imagawa H, Nagahama M.

Commun Med (Lond)

PMID:41991712

Free PMC article

Background Among pharmaceuticals currently in clinical use, few drugs directly target bacterial toxins. Clostridium perfringens α-toxin, a phospholipase C (PLC), is a major virulence factor responsible for gas gangrene caused by C. perfringens type A. There is a clinical need for small-molecule compounds that inhibit such bacterial toxins. Methods A library of 764 FDA-approved drugs was screened to identify compounds that inhibit the PLC activity of C. perfringens α-toxin. Identified hits were further evaluated for their ability to inhibit α-toxin-induced cytotoxicity in human umbilical vein endothelial cells (HUVECs). Additional in vitro assays were conducted to assess changes in neutrophil activation and cytokine production. In vivo efficacy was evaluated in female C57BL/6J mice (n = 21 or 18 per group) challenged with purified α-toxin or infected with C. perfringens type A. Results The initial screen identifies 21 compounds that inhibit the PLC activity. Among them, micafungin, an antifungal agent, is the only compound that suppresses α-toxin-induced cell death in HUVECs. Micafungin also reduces α-toxin-induced CD11b expression in neutrophils and cytokine release in HUVECs. Caspofungin, another antifungal with similar properties, also inhibits α-toxin-induced cell death and cytokine production. In mouse models, caspofungin, but not micafungin, significantly reduces lethality caused by α-toxin. Caspofungin also improves survival and mitigates muscle damage in mice infected with C. perfringens type A. Conclusions Caspofungin demonstrates promising therapeutic potential as a life-saving treatment for gas gangrene caused by C. perfringens type A, likely through its inhibitory action on α-toxin activity. These findings support the development of new classes of small-molecule therapeutics that directly target bacterial toxins.

Kapse BP, Soni RP.

Talanta

PMID:42008907

Free PMC article

Hyphenated analytical techniques, particularly liquid chromatography-mass spectrometry (LC-MS), play a central role in addressing the increasing complexity of modern bioanalytical challenges. Recent advancements in LC-MS hyphenation strategies have significantly improved sample preparation efficiency, analyte enrichment, and overall analytical performance. The integration of ion mobility spectrometry provides an additional orthogonal separation dimension, particularly effective for drug metabolism research and isomer discrimination. Furthermore, capillary electrophoresis hyphenation enables effective analysis of polar and charged metabolites, while ambient ionization approaches such as DESI and DART support rapid screening with minimal sample preparation. Tandem setups involving UV, fluorescence, and NMR provide essential layers of structural confirmation. Additionally, the shift toward microfluidic lab-on-a-chip platforms enables miniaturization, thereby reducing sample volume requirements and increasing analytical throughput. Despite these advances, challenges related to instrumental complexity, data interpretation, and regulatory harmonization continue to limit broader translation into routine practice. Collectively, these developments highlight the transformative potential of LC-MS while also emphasizing critical gaps that will shape future bioanalytical advancements.

Liu Y, Chen S, Lin K, Gao S, Li X.

J Chem Inf Model

PMID:41991475

Free PMC article

Precise prediction of bioactive conformations represents a central challenge in drug discovery. Traditional computational methods often rely on the assumption that the global minimum energy state corresponds to the bioactive conformation─a hypothesis with inherent limitations. Data-driven artificial intelligence (AI) models have revolutionized research methodologies in this domain. By learning the implicit probability distributions of conformations, AI demonstrates the potential to achieve high-precision predictions of bioactive structures. This review systematically surveys technical advancements ranging from geometric regression to generative and conditional generative models, analyzing their effectiveness in benchmarks and de novo design experiments. We deeply explore critical challenges, including data sparsity, sampling efficiency, generation capability, and interpretability. Finally, we provide an outlook on bridging the gap from "structural prediction" to "functional design" through the construction of dynamic data sets, the development of efficient algorithms, and the implementation of human-in-the-loop collaborative decision-making systems.

Gonzalez M, Palacios-Rodriguez P, Carazzone C.

PLoS One

PMID:41990106

Free PMC article

Poison frogs (Dendrobatoidea) are characterized by the great diversity of alkaloids discovered in their skin. However, most of these alkaloids have been found in brightly colored species and there is a wide lack of knowledge of alkaloid profiles in the less colorful species. Previous finding of paralytic tetrodotoxins (TTXs) in only two cryptically colored species from the genus Colostethus, establishes the unique occurrence of hydrophilic alkaloids in the superfamily Dendrobatoidea. Unpublished results using extracts from Colostethus imbricolus, demonstrated that this species contains paralysis-producing substances, after intraperitoneal injection of mice. To analyze their skin metabolites and to determine if they correspond to TTX, or TTX analogues, we have employed a TTX-targeted separation in normal phase gradient, and an untargeted profiling in reversed-phase gradient. After performing both analyses, neither TTX nor TTX-analogues were detected in C. imbricolus. In contrast, other metabolites were separated, allowing the extraction of 76 adducts common to both analyses, being 33 of them tentatively annotated as amphibian alkaloids, eight as amphibian metabolites different from alkaloids and 25 that matched with natural products from the DNP. A total of 10 common molecular formulas remained non-annotated. The absence of MS/MS spectra for these adducts requires their structures to be confirmed in future analyses, following the completion of targeted MS/MS acquisition. After analyzing the inter-individual variation of six specimens, it was demonstrated that the skin metabolome differs between males and females of C. imbricolus. Our results lead us to conclude that TTX is not the only paralyzing compound in dendrobatid frogs and that more work should be undergone to identify this phenomenon. A notable additional outcome of this study is the first successful separation of TTX on an SB-CN column using a normal-phase gradient, suggesting a potential useful approach for TTX-targeted separation.

Liu Y, Song Y, Wang Y, Wang J, Yang K.

Drug Discov Today

PMID:42000126

Free PMC article

Sphingosine-1-phosphate (S1P), a downstream metabolite of the sphingolipid pathway, exerts diverse biological functions, is implicated in a wide spectrum of diseases, and has been shown to have central roles in regulating cell proliferation, migration, and immune cell trafficking. Five agonists of its receptor have been approved for the treatment of multiple sclerosis, and an inhibitor targeting its production is currently undergoing clinical trials for cancer therapy. Here, we discuss the modulators and their preliminary structure-activity relationships in terms of the generation, transportation, and degradation of S1P.