Chemical studies on novel functional secondary metabolites from mushroom-forming fungi

Mushroom-forming fungi, primarily belonging to Agaricomycetes, produce a wide range of unique bioactive compounds. Many of these compounds exhibit pharmacological activities. This review summarizes our studies on biologically active compounds isolated from mushroom-forming fungi. In our research, we isolated and structurally elucidated 56 bioactive compounds, including endoplasmic reticulum stress suppressors, osteoclast-forming suppressing compounds, and Axl and immune checkpoint inhibitors. Notably, we discovered strophasterols, which possess unique and unprecedented carbon skeletons. Furthermore, we demonstrated that cyclopropylvirgines, a unique class of cyclopropane-containing natural products, occur naturally as racemates in mushroom-forming fungi. These findings highlight mushroom-forming fungi as a rich and underexplored source of structurally diverse bioactive natural products with great potential for drug discovery and pharmaceutical development.