Analysis of Secondary Metabolites from Plant Endophytic Fungi

Filamentous fungi produce a wide variety of secondary metabolites, which are recognized as a rich source of biomolecules with potential medicinal applications. According to chemical structures and biosynthetic pathways, secondary metabolites are mainly divided into four groups, including polyketide, nonribosomal peptides, alkaloids, and terpenes. Owing to their special living environment, plant endophytic fungi potentially produce many bioactive metabolites with diverse structural features. Some of these metabolites have been demonstrated to hold pharmaceutical and ecological significance. In order to identify bioactive compounds, different methods have been developed to isolate secondary metabolites from plant endophytic fungi. In this chapter, we describe the procedures for fungal fermentation, metabolite extraction, and analysis using high-performance liquid chromatography (HPLC). The endophytic fungus Pestalotiopsis fici, which was isolated from the healthy branches of Camellia sinensis (Theaceae), produces 88 secondary metabolites including 70 new natural products. Combining 74 secondary metabolite clusters revealed by genome sequencing analysis, P. fici is used as an example for analysis of secondary metabolites. The procedures could also be adopted for other fungi after small modifications.