Construction of a novel catalysis system for clean and efficient preparation of Baohuoside I from Icariin based on biphase enzymatic hydrolysis

Abstract

Baohuoside I has better in vivo bioactivities than Icariin. Its preparation methods, such as acid hydrolysis, are of low efficiency, with undesirable byproducts. The objective of this study was to establish a novel catalysis system for its clean and efficient preparation via biphase enzymatic hydrolysis. β-glucosidase was selected from five commercial enzymes due to the best catalysis performance. After optimization of conditions, a biphase system was constructed with EtOAc and HAc-NaAc buffer (pH 4.5) (5:1, v/v) containing Icariin/β-glucosidase (3.2:1, w/w), and hydrolysis was performed at 60 °C for 2 h. Consequently, the conversion rate of Icariin was 99.92 ± 0.11% (n = 3), and the processing capacity in the system was increased from 20 mg/mL to 50 mg/mL, 2.5 times that of conventional enzymatic hydrolysis, meanwhile the procedure was much simplified. Additionally, complete hydrolysis with conversion rate at 99.14% had been achieved after the enzyme solution was used twice. The newly proposed strategy is a clean and efficient approach for the preparation of Baohuoside I and also a promising technology for producing secondary glycosides or aglycones.