Composition, biosynthesis and pharmacological activities of chemical constituents of <i>Ophiocordyceps sinensis</i>: a review

<italic>Ophiocordyceps sinensis</italic> (syn. DongChongXiaCao), a rare and endemic medicinal fungus native to China, possesses significant pharmacological and commercial value. However, the chemical composition, pharmacological mechanisms, and biosynthetic pathways of secondary metabolites in <italic>O. sinensis</italic> remain largely uncharacterized, hindering efforts to enhance its quality and develop derived products. This review summarizes the resource status, chemical constituents, and pharmacological properties of <italic>O. sinensis</italic>, with a focus on the omics research progress and the biosynthetic pathways of key secondary metabolites such as cordycepin, ergosterol, and polysaccharides. Modern pharmacological studies reveal that <italic>O. sinensis</italic> exhibits immunomodulatory, anti-inflammatory, antitumor, anti-aging, antihypertensive, and antioxidant activities, primarily attributed to its polysaccharides, nucleosides, sterols, and peptides. Despite advancements in omics technologies for studying its unique developmental mechanisms and secondary metabolite biosynthesis, knowledge in this field remains limited, especially compared with congeneric species. Finally, future research directions, including the development of quality biomarkers, exploration of complex macromolecules, investigation of <italic>O. sinensis</italic>-environment interactions, and artificial cultivation techniques, are proposed to alleviate resource scarcity. This review highlights current research gaps and provides actionable solutions, laying a foundation for the subsequent development of related products and the sustainable utilization of <italic>O. sinensis</italic>.