利用环糊精糖基转移酶转化合成AA-2G的研究

Enzyme Synthesis of AA-2G by Cyclodextrin Glycosyltransferase

摘要:

利用环糊精糖基转移酶（CGT-SL）对转化合成2-O-α-D-吡喃葡萄糖基-L-抗坏血酸（AA-2G）的条件进行考察。反应产物通过HPLC/LC-MS分析确定含有AA-2G。以便宜易得的可溶性淀粉和VC作为底物，在初始反应条件下AA-2G的产量为1.23 g/L。通过转化条件优化初步确定了转化反应的最优条件：最适温度15 ℃，最适pH 4.0，转化反应时间32 h，底物VC和可溶性淀粉的比例为2∶4，VC质量浓度为16 g/L，酶浓度为79 U/mL时，AA-2G的产量达到6.23 g/L，VC转化率为19.93%。

Abstract:

The enzymatic synthesis condition of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid（AA-2G） was studied in this dissertation. AA-2G was synthesized by using cyclodextrin glycosyltransferase（CGT-SL，support by Amano），and soluble starch and VC as the substrate. Under the initial condition，AA-2G production was 1.23 g/L. The best conditions for the synthesis of AA-2G：time 32 h，temperature 15 ℃，pH 4.0，concentration of VC 16 g/L，the proportion of VC and soluble starch is 2∶4，the concentration of CGT-SL 79 U/mL. Under these conditions，the final production of AA-2G was 6.23 g/L，and the transformation rate of VC reached 19.93%.