Bioactive Secondary Metabolites from Endophytic Fungi: Biological Activities and Applications

Secondary metabolites synthesised by endophytic fungi have attracted considerable interest due to their broad applicability across pharmaceutical, agricultural and industrial fields. The breadth of chemical diversity offered by endophytic fungi includes alkaloids, terpenoids, steroids, polyketides, and flavonoids, many of which demonstrate potent antimicrobial, anticancer, anti-inflammatory and antioxidant effects. A key problem addressed in recent research is the urgent need for new and effective natural compounds to combat rising antimicrobial resistance, cancer, and various plant and human diseases. This review systematically evaluates the diversity, biosynthesis, and biological activities of secondary metabolites generated by endophytic fungi. Specifically, it explores the intricate relationship between endophytes and their host plants, which contributes to metabolite production and functional diversity. The review also highlights the mechanisms by which these fungi confer ecological advantages and outlines the challenges and prospects in harnessing their potential for drug discovery and crop management. Recent studies in this review show that there are many types of endophytic fungi that have not yet been explored. We also need to understand more about how these fungi make useful compounds and how these compounds work in living things. By integrating current findings, the review underscores the ongoing promise and future potential of endophytic fungi as sources of innovative and sustainable solutions to urgent medical and agricultural problems.