Exploring antimycobacterial potential: safety evaluation and active compound isolation from gymnopilus junonius
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Multidisciplinary Digital Publishing Institute (MDPI)
Abstract
Background/Objectives: Tuberculosis remains a major public health crisis, and it is imperative to search for new antimycobacterial drugs. Natural products, including medicinal macrofungi, have been used as sources for the discovery of pharmaceuticals; however, research on their antimycobacterial activity remains limited. This study aimed to isolate and identify the bioactive compound responsible for antimycobacterial activity, thereby expanding on the limited knowledge regarding the antimicrobial activity and bioactive compounds present in Gymnopilus junonius. Methods: Bioassay-guided fractionation using column chromatography and preparative thin-layer chromatography were employed to isolate the active compound. Antimycobacterial activity against Mycobacterium tuberculosis H37 was assessed using a resazurin microplate assay (REMA). The chemical structure was determined by 1H nuclear magnetic resonance (NMR) spectroscopy, heteronuclear single quantum coherence (HSQC) spectroscopy, heteronuclear multiple bond correlation (HMBC) spectroscopy, and high-resolution electrospray ionization mass (HR-ESI-MS) spectrometry. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes in M. tuberculosis induced by the compound. Cytotoxicity was evaluated in African green monkey kidney cells (Vero), human liver cells (C3A), and zebrafish embryos/larvae. Results: Bioassay-guided fractionation led to the isolation of gymnopilene, which showed inhibitory activity against M. tuberculosis (MIC: 31.25 µg/mL). TEM analysis revealed that treatment with gymnopilene caused ultrastructural damage observed as the disruption and disintegration of the cell wall. While gymnopilene demonstrated cytotoxicity in Vero and C3A cells, no toxicity was observed in zebrafish embryos/larvae for the crude extract. Conclusions: This study highlights that macrofungi, such as G. junonius, could be a valuable resource of bioactive compounds.
Description
Keywords
Antimycobacterial activity, Cytotoxicity, Gymnopilene, Gymnopilus junonius, Mycobacterium tuberculosis
Citation
Didloff, J., Boukes, G.J., Nyambe, M.N., Beukes, D.R., Lerata, M.S., Vilane, V., Lee, M., Govender, S. and van de Venter, M., 2025. Exploring Antimycobacterial Potential: Safety Evaluation and Active Compound Isolation from Gymnopilus junonius. Antibiotics, 14(2), p.179.