Natural Product Synthesis by Fungi: Recent Trends and Future Prospects

Abstract

Fungi are amazing producers of natural products and thus they are crucial to the health and well-being of people throughout the world. Approximately 70,000 fungal species are recognized, although far more than 1 million are estimated to occur. Fungi can inhabit almost all the ecological niches in the world and are considered by their ability to create secondary metabolites or minor molecule natural products. Consequently, many of these secondary metabolites are not directly involved in the common growth, development, or reproduction of the fungi in which they occur, but rather may be essential in stress tolerance and ecological interactions with other organisms. Fungal secondary metabolites display a variety of biological activities and are of interest to the food, agrochemical, and pharmaceutical industries. The secondary metabolites produce from some common biosynthetic pathways, but the consequential intermediates undergo numerous enzyme-catalyzed reactions resulting in an extremely diverse group of chemical structures. Therefore, the bulk of these secondary metabolites are readily categorized on the basis of their biosynthetic origins as polyketides, alkaloids, terpenoids, nonribosomal peptides, and cyto-chalasins. These valuable molecules, recognized as nonribosomal peptides, are produced by a group of enzymes named nonribosomal peptide synthetases (NRPSs) that assemble diverse natural products including penicillin (antibacterial), beauvericin (anticancer), vancomycin (antibacterial), and peramine (anti-insect). Moreover, novel screening approaches based on innovative biological, chemical, and genetic methods have led to new fungal metabolites in recent years. This chapter highlights current knowledge about fungal natural products, including primary and secondary metabolites, their biosynthetic pathways, and brief examples of each class of compounds, including their bioactivity.