Abstract: In a non-traditional reaction system with ionic liquid, mixed organic solvents and buffer solution, synthesis of salidroside with highly operation stable cross-linked b-glucosidase aggregates by direct glycosylation under enzymatic catalysis was studied. Based on the optimization of the composition of reaction media and the proportion of each component, the reaction system was determined as follows in volume ratio: 8.5% of ionic liquid C4MIm×PF6, 42.5% of 1,4-dioxane, 34.0% of ethyl acetate, and 15.0% of citric acid-disodium hydrogen phosphate buffer (pH 6.0). In this reaction system, the water activity was maintained at the proper level which was suitable to the direct glycosylation even though the water content of the system was up to 15%. So, at the reaction temperature of 50℃ and the rotating speed of 250 r/min, when b-D-glucose content was 100 g/L and p-hydroxyphenylethanol content 200 g/L, the equilibrium concentration of salidroside could reach up to 25.32 g/L after reaction for 120 h.

Key words: enzymatic catalysis, cross-linked b-glucosidase aggregate, salidroside, direct glycosylation, ionic liquid

摘要： 采用具有较高操作稳定性的交联b-葡萄糖苷酶聚集体，在离子液体-混合有机溶剂-缓冲溶液的非常规反应体系中酶催化直接糖基化合成红景天苷，筛选反应体系的组成和各成分的比例. 结果表明，反应体系的组成为(%, j)：1,4-二氧六环42.5, 离子液体C4MIm×PF6 8.5, 乙酸乙酯34, pH 6.0柠檬酸-磷酸氢二钠缓冲溶液15.0. 该体系在水含量高达15%(j)的条件下水活度为0.66，适合直接糖基化反应. 底物b-D-葡萄糖100 g/L、对羟基苯乙醇200 g/L时，在50℃及250 r/min下反应120 h达到平衡，红景天苷最大浓度可达25.32 g/L.

关键词: 酶催化, 交联b-葡萄糖苷酶聚集体, 红景天苷, 直接糖基化, 离子液体