Icaritin Preparation from Icariin by a Special Epimedium Flavonoid-Glycosidase from Aspergillus sp.y848 Strain

J Microbiol Biotechnol. 2022 Feb 11;32(4):1-8. doi: 10.4014/jmb.2112.12036. Online ahead of print.ABSTRACTTo obtain the icaritin with high pharmacological activities from icariin, which content ratio over 58% in the total flavonoids of Epimedium Herb, a special Epimedium flavonoid-glycosidase was produced, purified and characterized from Aspergillus sp.y848 strain. The optimal enzyme production was gained in the medium containing 5% (w/v) wheat bran extract and 0.7% (w/v) Epimedium leaf powder as the enzyme inducer, and strain culture at 30°C for 6-7 days. The molecular weight of the enzyme was approximately 73.2 kDa; the optimal pH and temperature were 5.0 and 40°C. Enzyme Km and Vmax for icariin were 15.63 mM and 55.56 mM/h. The enzyme hydrolyzed the 7-O-glucosides of icariin into icariside II, finally hydrolyzed 3-O-rhamnoside of icariside II into icaritin. The enzyme also hydrolyzed 7-O-glucosides of epimedin B to sagittatoside B, further hydrolyzed terminal 3-O-xyloside of sagittatoside B to icarisiede II, finally hydrolyzed 3-O-rhamnoside of icarisiede II into icaritin. The enzyme only hydrolyzed 7-O-glucoside of epimedim A or epimedin C into sagittatoside A or sagittatoside C. It is possible to prepare the icaritin from the high content icariin in Epimedium herb using the enzyme. When 2.5% icariin was reacted at 40°C for 18-20 h by the low-cost crude enzyme, 5.04 g icaritin with 98% purity was obtained from 10 g icariin. The icaritin molar yield was 92.5%. So, the i...
Source: Journal of Microbiology and Biotechnology - Category: Biotechnology Authors: Source Type: research