Icaritin production from Epimedium folium extract by a one-pot enzymatic cascade of a multifunctional glycosidase and rhamnosidase.

Abstract

Icaritin (ICT), a compound with diverse biological activities derived from Epimedium folium, is typically present in low concentrations in EFs. However, the abundant glycosyl-modified ICT compounds facilitate its transformation into ICT. Current biocatalytic production faces challenges, including low conversion rates and limited enzyme activity. This study developed a one-pot enzymatic cascade strategy for directly biotransform crude extracts of Epimedium folium (EEF) to produce ICT. The feasibility of catalyzing different ICT-related compounds in EEF was validated through molecular docking and substrate reactions. The selected glycosidase exhibited simultaneous activities as a glucosidase, xylosidase, and α-1,6-rhamnosidase, with the rhamnosidase showing outer-rhamnosidic activity and weak glucosidase activity. By using EFs as the substrate and employing whole-cells (Escherichia coli) containing LacS and BtRha proteins for synergistic catalysis, icariin can be efficiently synthesized within 6 h, achieving a conversion rate of 100 %. The enzymatic cascade for ICT production from crude extracts was elucidated by analyzing catalytic intermediates via HPLC. Compared to strategies using single or traditional multi-enzyme applications, this method shows advantages of ease to operation, high efficiency, and large production yield performance. This method has the potential to become an eco-friendly catalytic strategy for the large-scale production of icaritin.