Secondary metabolites from marine fungi: current status and application

Secondary metabolites isolated from marine fungi have added significantly to the field of natural product research. Many of these compounds offer structural and functional uniqueness and are relevant in medical, agriculture, and bioeconomy industries. With sources in not only marine fungi living in inorganic habitats (soil, deep sea sediments, debris) but also marine plants, and invertebrates and vertebrates, bioactive secondary metabolites have caused significant interest in the research community to explore these sources for discovering the riches. Due to the extreme biotic and abiotic conditions in the marine ecosystem, marine fungi have developed metabolic pathways to produce diverse chemical scaffolds. Among the several sources, marine algae and sponges represent a rich source of fungal diversity. The commonly reported genera include Penicillin, Aspergillus, Cladosporium, Fusarium, Trichoderma, Acremonium, Phoma, and Chaetomium. Polyketides are the most reported secondary metabolites, followed by alkaloids, terpenoids and peptides, and lipids. These compounds have a broad array of pharmacological properties, including antimicrobial, anticancer, antiviral, antioxidative, antiinflammatory, etc. The bioactive properties are induced by DNA damage, targeting the cell membrane, a series of proteins in an essential pathway, etc. Plinabulin, a dehydrodiketopiperazine from a marine fungus Aspergillus, is currently running in several clinical trials for the treatment of advanced metastatic cancers. The low yield and specificity of secondary metabolites have often imposed a hurdle in commercializing natural fungal products. This can be tackled with strain improvement, media manipulation strategies, and interdisciplinary approaches to introduce sustainable bioactive secondary metabolites production factories. It is by understanding the biology of marine fungi through omics that next-generation sequencing approaches will diversify the incredible prospects of these microfactories. This chapter provides the impetus for the pharmaceutical application of marine fungal biotechnology.