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

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