Efficient Biosynthesis of 8-Prenylkaempferol from Kaempferol by Using Flavonoid 8-Dimethylallyltransferase Derived from Epimedium koreanum

The genus Epimedium includes popular Chinese medicinal plants, and icariin and its precursor icaritin are the key bioactive components of Epimedium. Here, we identified flavonoid 8-dimethylallyltransferase (F8DT) in the authentic medicinal material of Epimedium koreanum, which is a key gene in the icariin biosynthesis pathway. This enzyme can catalyze the synthesis of 8-prenylkaempferol (8PK) from kaempferol. The catalytic ability of the rate-limiting enzyme EkF8DT was significantly improved by truncating its N-terminal intrinsically disordered regions (IDRs) and enhancing the flux of the mevalonate pathway. Icaritin was also successfully synthesized by introducing flavonoid 4'-O-methyltransferase into the Saccharomyces cerevisiae strain. Finally, the highest production of 8PK and icaritin (3.6 g/L and 172.0 mg/L, respectively) was obtained in the S. cerevisiae strain.