Exploring Antimycobacterial Potential: Safety Evaluation and Active Compound Isolation from Gymnopilus junonius

Area of Science:

• Mycology
• Medicinal Chemistry
• Microbiology

Background:

• Tuberculosis (TB) is a significant global health issue requiring novel therapeutic agents.
• Medicinal macrofungi are underexplored sources for antimycobacterial drug discovery.
• Limited research exists on the antimicrobial properties of Gymnopilus junonius.

Purpose of the Study:

• To isolate and identify bioactive compounds from Gymnopilus junonius with antimycobacterial activity.
• To characterize the mechanism of action against Mycobacterium tuberculosis.
• To assess the cytotoxicity of isolated compounds.

Main Methods:

• Bioassay-guided fractionation using chromatography to isolate the active compound.
• Resazurin microplate assay (REMA) to determine minimum inhibitory concentration (MIC) against Mycobacterium tuberculosis H37.
• Spectroscopic techniques (NMR, HSQC, HMBC, HR-ESI-MS) for structural elucidation.
• Transmission electron microscopy (TEM) to visualize cellular damage.
• Cytotoxicity assays in Vero cells, C3A cells, and zebrafish.

Main Results:

• Gymnopilene was isolated and exhibited antimycobacterial activity with an MIC of 31.25 µg/mL against Mycobacterium tuberculosis.
• TEM revealed that gymnopilene disrupts and disintegrates the cell wall of Mycobacterium tuberculosis.
• Gymnopilene showed cytotoxicity in mammalian cell lines (Vero, C3A), but the crude extract was not toxic to zebrafish.

Conclusions:

• Gymnopilus junonius is a potential source of novel antimycobacterial compounds.
• Gymnopilene is a promising lead compound for developing new anti-TB drugs.
• Further research is warranted to explore the therapeutic potential and safety profile of gymnopilene.