Coupled biosynthesis of cordycepin and pentostatin in Cordyceps militaris: implications for fungal biology and medicinal natural products

Cordycepin, or 3'-deoxyadenosine, is a metabolite produced by the insect-pathogenic fungus Cordyceps militaris and is under intense investigation as a potential lead compound for cancer and inflammatory conditions. Cordycepin was originally extracted by Cunningham et al. (1) from a culture filtrate of a C. militaris culture that was grown from conidia. Subsequently, cordycepin has also been reported to be produced by Ophiocordyceps sinensis (2), a species historically used as a traditional medicine and health food, primarily in China and the wider Far East (3). Cultivated C. militaris is now widely in use as less expensive substitute. In addition, these fungi are also globally gaining a market as natural food supplements, with 30–50 products claiming to contain Cordyceps available in the UK and the USA.