Enzymatic Glucosylation of Salidroside from Starch by alpha-Amylase
Enzymatic Glucosylation of Salidroside from Starch by alpha-Amylase
复制标题
α-淀粉酶对淀粉中的红景天苷进行酶促糖基化
DOI：
10.1021/acs.jafc.8b06618
复制
发表时间：
2019
影响因子：
6.1
通讯作者：
Lu Lili
中科院分区：
文献类型：
--
作者：
Wang Ke;Qi Tingting;Guo Longcheng;Ma Zhongxuan;Gu Guofeng;Xiao Min;Lu Lili
α-淀粉酶是淀粉加工中最重要和最广泛使用的工业酶之一。本工作从枯草芽孢杆菌XL 8菌株中分离纯化了一种α-淀粉酶，该酶具有水解和转糖基活性。淀粉水解的最适pH为5.0，最适温度为70 °C。该酶可将可溶性淀粉降解为有益的麦芽低聚糖，范围从二聚体到六聚体。更重要的是，它能够催化α-糖基从可溶性淀粉转移到红景天苷，一种具有广泛药理学性质的药用植物来源的成分。在100 mg/mL可溶性淀粉和50 mM红景天苷（pH7.5）中，50 °C反应2 h，酶催化的转糖基化反应生成6个衍生物，总收率高达73.4%。这些衍生物分别被鉴定为α-1，4-葡萄糖基、麦芽糖基、麦芽三糖基、麦芽四糖基、麦芽五糖基和麦芽六糖基红景天苷。这两个化合物是一个很有前途的新化合物，可能整合了麦芽低聚糖和红景天苷的生物活性功能。
α-Amylases are among the most important and widely used industrial enzymes for starch processing. In this work, an α-amylase fromBacillus subtilisXL8 was purified and found to possess both hydrolysis and transglycosylation activities. The optimal pH and temperature for starch hydrolysis were pH 5.0 and 70 °C, respectively. The enzyme could degrade soluble starch into beneficial malto-oligosaccharides ranging from dimer to hexamer. More importantly, it was able to catalyze α-glycosyl transfer from the soluble starch to salidroside, a medicinal plant-derived component with broad pharmacological properties. The transglycosylation reaction catalyzed by the enzyme generated six derivatives in a total high yield of 73.4% when incubating with 100 mg/mL soluble starch and 50 mM salidroside (pH 7.5) at 50 °C for 2 h. These derivatives were identified as α-1,4-glucosyl, maltosyl, maltotriosyl, maltotetraosyl, maltopentaosyl, and maltohexaosyl salidrosides, respectively. They were novel promising compounds that might integrate the bioactive functions of malto-oligosaccharides and salidroside.