Extracts of the Algerian Fungus Phlegmacium herculeum: Chemical Analysis, Antioxidant, Antibacterial, and Cytotoxicity Evaluation

This study reports the first molecularly confirmed occurrence of <i>Phlegmacium herculeum</i> in Algeria, identified through morphological features and ITS sequence analysis (GenBank accession: PQ133121). Phytochemical profiling revealed a diverse composition of metabolites. SPME-GC-MS analysis detected volatile aldehydes (butanal, pentanal), organic acids (butanoic, pentanoic), terpenoids (limonene, 1,8-cineole), phenolics, and long-chain alkanes. Furthermore, the macrofungus has been extracted with organic solvents, and the obtained extracts have been analyzed via NMR and GC-MS, revealing the presence of organic acids (lactic, succinic, azelaic), fatty acids (palmitic, linoleic), and phenolic acids (protocatechuic, 4-hydroxybenzoic). DPPH-based analysis indicated that the antioxidant response of the crude extracts strengthened as the dose increased, with the ethyl acetate (EtOAc) extract exhibiting the highest inhibition and lowest IC₅₀, attributed to its rich phenolic content. The chloroform (CHCl₃) extract showed moderate activity, consistent with its composition of less polar metabolites such as fatty acids and terpenoids. Antibacterial assays revealed extract-specific effects: CHCl₃ strongly inhibited <i>Staphylococcus aureus</i> (18 mm), while EtOAc was more effective against Gram-negative strains, including <i>Escherichia coli</i> (18 mm) and <i>Pseudomonas aeruginosa</i> (13 mm). Cytotoxicity testing using <i>Saccharomyces cerevisiae</i> confirmed that both extracts were non-toxic, maintaining ≥90% cell viability. These findings highlight <i>P. herculeum</i> as a novel source of bioactive metabolites with antioxidant and antibacterial potential.