Controllable Biotransformation of Naringin to Prunin by Naringinase Immobilized on Functionalized Silica

BACKGROUND Mesoporous silica materials, with high specific surface area, tailorable pore size and excellent chemical stability, have wide prospects for application in catalyst carriers. In this work, aldehyde-modified silica materials were first prepared through silanization reaction of N-[3-(trimethoxysilyl)propyl]ethylenediamine and then Schiff base reaction of glutaraldehyde. Subsequently, the resulting materials were used for immobilization of naringinase. RESULTS The results demonstrated that the activity of immobilized naringinase was optimized as 352.83 U g(-1) support. The optimal immobilization conditions were determined as follows: immobilization temperature of 30 degrees C, immobilization time of 3 h, pH of 3.5 and initial naringinase activity of 200.75 U mL(-1). In addition, at the optimal reaction temperature of 50 degrees C and pH of 8.0, the percentage of immobilization, naringinase activity recovery and naringinase activity of the immobilized naringinase reached 56.41%, 93.42% and 423.22 U g(-1) support, respectively. Besides, comparing with free naringinase, in the process of naringin hydrolysis, the immobilized naringinase exhibited wide pH application range and good thermal stability, and still maintained 71.13% residual naringinase activity after 1 month of storage. Even more important, the immobilized naringinase could controllably transform naringin to prunin as the only hydrolysis product, and no naringenin was detected, which represents a new route for controllable preparation of prunin. CONCLUSIONS This study provides an ideal carrier material and some basic data for naringinase immobilization technology, which will greatly promote the application of naringinase and the development of the pharmaceutical industry. (c) 2020 Society of Chemical Industry