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

Abstract

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.