The chemical structures, biosynthesis, and biological activities of secondary metabolites from the culinary-medicinal mushrooms of the genus Hericium: A review

Fungal phytochemicals derived from higher fungi, particularly those found in the culinary-medicinal fungi Hericium, have gained importance in drug discovery and healthcare. This review aims to provide a comprehensive summary of the chemical structures, biosynthesis, biological activities, and pharmacological properties of monomer compounds derived from Hericium. Over the past 34 years, 253 metabolites have been identified from various Hericium species, including cyathane diterpenes, alkaloids, benzofurans, chromenes, phenols, pyrones, steroids, and miscellaneous compounds. The biosynthesis of erinacines, a type of cyathane diterpene, has been investigated, leading to the discovery of unnatural cyathane diterpenes. Extensive researches have been conducted on the biological activities and pharmacological properties of Hericium compounds, with a particular focus on their neuroprotective and neurotrophic effects, immunomodulation, anticancer activity, antioxidant properties, and antimicrobial action. Erinacine A, in particular, has been well-researched. Genomic, transcriptomic, and proteomic studies of Hericium have also been conducted, enabling the discovery of new compounds and guiding enzymatic chemical reactions through genome mining. The diverse chemical structures and biological activities of Hericium compounds provide a solid foundation for their use in medicine and as food supplements. Overall, this review not only enhances our understanding of Hericium compounds but also promotes further investigation of Hericium species in the fields of medicine, health, functional foods, and agricultural microbiology. The wide range of compound types and their diverse biological activities offer exciting opportunities for the discovery of pharmaceutical and edible chemicals.