Endophytic Fungi Natural Factories of Novel Bioactive Compounds.

Endophytic fungi represent a prolific and chemically diverse source of novel specialized metabolites with significant pharmacological potential. This systematic review examines 118 studies published between 2024 and 2025, reporting the discovery of 242 previously uncharacterized bioactive compounds. These metabolites belong to several major chemical classes, including peptides (4), terpenoids and steroids (58), alkaloids and other nitrogen-containing compounds (51), polyketides (85), lactones (22), ketones (5), chromone compounds (3), and others (9). The genera Aspergillus (28), Penicillium (21), Diaporthe (7), Talaromyces (10), and Trichoderma (6) were identified as the most productive sources. The investigated endophytic fungi were isolated from a wide range of plant hosts and ecological niches, reflecting the extensive biodiversity of endophytic communities. Biological screening demonstrated that a substantial proportion of the tested compounds exhibited diverse bioactivities, including anti-inflammatory, antibacterial, antifungal, antimicroalgal, and cytotoxic effects. Collectively, the remarkable structural diversity and broad biological profiles of metabolites derived from endophytic fungi highlight their strong potential as promising lead scaffolds for future pharmaceutical development.