Marine Fungi as a Bioresource of Medicinal Entities

The search for new drugs is the aim of drug discovery research. Even today, biodiversity is the inspirational source of novel metabolites, and marine environments have proven to possess an exceptional chemical space. Marine fungi have received immense attention as sustainable producers of unique secondary metabolites with promising bioactive properties, such as immunomodulatory, anticancer, anti-inflammatory, antimicrobial, and antivirals. Marine fungi are often found in symbiotic association with higher organisms, such as tunicates, corals, sponges, mollusks, cnidarians, and fish, as well as seaweeds, mangroves, and kelps. They are also found in seawater, deep-sea sediments, and the intertidal region. As an adaptive evolution, the marine fungal metabolites possess unique carbon skeletons, halogenated decorations, functional groups, and heterocyclic structures that contribute to more significant bioactivity than terrestrial sources. The roadmap for a marine natural product to the market involves several stages, including sampling, isolation and taxonomic identification of fungi, extraction of secondary metabolites, primary screening for specific bioactivities, isolation of a pure compound, secondary screening for target identification using genetic and biochemical screens, yield enhancement, in vivo studies, preclinical and clinical analysis, costing, and market approval. The advances in genomics, metabolomics, data science, automation, and robotics have immensely eased the roadmap and accelerated novel compound discovery. The generation of compound libraries has allowed the exploration of new bioactivities for known structures. However, to limit the dereplication of known compounds, efforts must be undertaken to explore marine-specific fungi and innovative marine-specific culture conditions. This chapter aims to highlight the incredible potential of marine fungi as a bioresource of medicinal compounds and the several advancements in natural product research that can accelerate the approval of a fungal drug.