桑树黄酮苷芦丁定向糖基改造的液滴微流控酶催化研究

Directional Deglycosylation of Mulberry Flavonoid Glycoside Rutin Catalyzed by Enzyme Using Droplet Microfluidic Technology

设计新颖的生物催化体系对桑树黄酮苷的特定糖基进行定向改造,以制备高附加值的活性产物。利用微芯片制备油包水型液滴,考察分散相与连续相的压力对液滴生成频率及粒径的影响,并在载有α-L-鼠李糖苷酶的液滴中微流控催化芦丁的鼠李糖基水解反应。结果表明,以流动聚焦型芯片制备液滴相对稳定,当分散相和连续相压力分别为125×10^4Pa和15×10^4Pa时,液滴生成频率高达191 min^-1,最大粒径为15 mm,有效避免了液滴聚集。采用响应曲面法优化液滴微流控酶催化芦丁水解制备异槲皮苷的工艺条件,当温度为35℃、底物质量浓度为002 g/L、缓冲液pH值为55时,产物的时空产率高达(755±13)μg/(m3·d)。因此,液滴微反应器用于桑树黄酮苷的糖基定向改造具有良好的可行性。

A novel biocatalysis system was designed to directionally modify specific glycosyl of mulberry flavonoid glycoside to prepare high value-added products. W/O droplets were prepared by microfluidic chip to investigate influence on frequency and size of formatted droplets by pressure of dispersed phase and continuous phase,and rhamanopyranosyl of rutin was directional hydrolyzed using α-L-rhamnosidase as a catalyst in the droplet microreactor. Results showed that flow-focused microfluidic chip was relatively stable. When pressures of dispersed phase and continuous phase were 1 25×10^4 Pa and 1 5×10^4 Pa respectively,droplet frequency peaked at 191 min^-1 and maximum droplet size was 1 5 mm,which could effectively avoid droplet aggregation. In addition,spatio-temporal yield of product as high as(75 5±1 3)μg/(m3·d)was obtained under the following optimal enzyme-catalyzed reaction conditions using droplet microfluidic technology to hydrolyze and prepare isoquercitrin from rutin:temperature 35 ℃,buffer concentration 0 02 g/L,buffer pH 5 5. In conclusion,droplet microreactor is feasible for directional deglycosylation of mulberry flavonoid glycoside.