摘要
以亲水性固体材料吸附p-羟基苯乙醇的形式以及补加葡萄糖方式,通过β-葡萄糖苷酶在水-1,2-二乙酰氧基乙烷体系中催化p-羟基苯乙醇直接糖基化反应制备p-羟基苯乙基β-D-葡萄糖苷。当硅藻土吸附p-羟基苯乙醇的吸附量为0.06mol·g-1,体系水分活度(aW)0.78,52℃,pH6.2时,在p-羟基苯乙醇为0.6mol·L-1,与葡萄糖摩尔比为3的条件下,反应24h,反应产率达25.63%,产物浓度为0.051mol·L-1;采取反应后期补加葡萄糖到初始浓度,继续反应24h,总反应产率达40.15%,产物总浓度为0.101mol·L-1。而两次补加的总反应产率达41.10%,产物总浓度为0.124mol·L-1。实验结果表明,吸附形式p-羟基苯乙醇和补加葡萄糖两种方式对在水-1,2-二乙酰氧基乙烷体系中的酶催化直接糖基化反应过程都具有明显的强化作用。
The preparation of p-hydroxyl phenylethyl β-D-glucoside via β-glucosidase catalyzed direct o-glucosylation of p-hydroxyl phenylethanol in aqueous-1,2-diacetoxyethane system were enhanced by using adsorbing p-hydroxyl phenylethanol onto solid supports and adopting step-addition of β-D-glucose. Celite 545, silica gel and clay were selected as adsorbents and solid supports of the p-hydroxyl phenylethanol. The experiments show that all the above adsorbents have enhancement effect for the glucosylation reaction, and among them the Celite 545 is most effective. A yield of 25.63% （product content of 0.051 mol·L^-1 could be obtained under the conditions of the aqueous system with water activity （αw） of 0.78, temp. of 52℃ and pH of 6.2 and the content of p-hydroxyl phenylethanol adsorbed onto Celite 545 is 0.6 mol·L^-1, the molar ratio of aglycone/glycone is 3, reaction time is 24 h. Then, step-adding β-D-glucose and continuing the reaction for further 24 h, the yield reaches 40.15% （product content of 0.101 mol·L^-1）. After the second step-addition of β-D-glucose and reaction for another 24 h, a total yield of 41.10% （product content of 0.124 mol·L^-1） can be reached. The results suggest that both the measures of absorbing p-hydroxyl phenylethanol onto solid support and step-adding β-D-glucose have obvious enhancement effects on the yield of enzymatic preparation of p-hydroxyl phenylethyl β-D-glucoside.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2009年第1期87-91,共5页
Journal of Chemical Engineering of Chinese Universities
