β-葡萄糖苷酶纳米凝胶非水相合成红景天苷

Synthesis of salidroside by β-glucosidase nanogel in non-aqueous media

为了高效制备红景天苷,采用水相原位聚合的方法制备β-葡萄糖苷酶纳米凝胶作为催化剂,以葡萄糖和酪醇为底物,在非水相体系中通过逆水解合成红景天苷。对酶纳米凝胶的耐受性以及影响合成红景天苷的多种因素如反应体系的有机溶剂种类、含水量、加酶量、pH、温度和底物浓度等作了考察。实验结果表明:由于酶纳米凝胶能够有效增强酶的热稳定性和有机溶剂耐受性,非常适合β-葡萄糖苷酶逆水解合成红景天苷反应的进行;优化后的合成条件表明以叔丁醇作为有机溶剂,反应体系含水量为5%,加酶量4.0U/m L,体系pH6.0,反应温度60℃,葡萄糖和酪醇的浓度分别为300mmol/L和900mmol/L,经过96h的反应,红景天苷浓度为71.13mmol/L,收率达到23.7%。本研究提供了酶法合成红景天苷更高效的新方法。

To efficiently prepare salidroside,the encapsulation of β-glucosidase into nanogel was accomplished via the two-step in situ polymerization and used as the catalyst to synthesize salidroside with glucose and tyrosol as substrates in a non-aqueous system by reverse hydrolysis. The tolerance of the enzyme nanogel and the effects of different organic solvents,water content,enzyme dosage,pH,temperature and the substrate concentration on the synthesis of salidroside were investigated. Because the enzyme nanogel could effectively enhance the thermo-stability and the tolerance of organic solvents,β-glucosidase nanogel was well suitable for the synthesis of salidroside by reverse hydrolysis. The results showed that t-butanol was the best organic solvent whenthe water content of system was 5%,the enzyme dosage was 4.0 U/m L,the pH was 6.0,the reaction temperature was 60℃,and the concentrations of glucose and tyrosol were 300 mmol/L and 900 mmol/L,respectively. Under the optimized conditions,the concentration of salidroside was 71.13 mmol/L,and the yield could reach up to 23.7% after reaction for 96 h. The research provided a new and more effective approach for enzymatic synthesis.