l-Menthol was glucosylated by the α-glucosidase (EC 3.2.1.20) of Saccharomyces cerevisiae using maltose as the glucosyl donor. When 50 mg of l-menthol and 1.6 M maltose in 10 mM citrate-phosphate buffer (pH 5.5) were incubated at 45°C, l-menthyl α-D-glucopyranoside (α-MenG) was α-anomer-selectively formed as a product. The specificity of the α-linkage was confirmed by 13C-NMR analysis. In the reaction mixture after 2 h, α-MenG was mainly accumulated in a crystalline form and the concentration of dissolved α-MenG was constant at 1.4 mM. The molar conversion yield of α-MenG produced based on the supplied l-menthol was maximally 30.7% at 48 h of reaction.
以
麦芽糖为
葡萄糖基供体,通过酿酒酵母的α-
葡萄糖苷酶(
EC 3.2.1.20)对薄荷醇进行
葡萄糖基化。在 10 mM
柠檬酸盐-
磷酸盐缓冲液(pH 5.5)中加入 50 mg l-menthol 和 1.6 M
麦芽糖,在 45°C 下孵育,l-menthyl α-D-glucopyranoside (α-MenG)作为一种产物选择性地形成了 α-异构体。13C-NMR 分析证实了 α 连接的特异性。2 小时后,α-MenG 在反应混合物中主要以结晶形式积累,溶解的 α-MenG 浓度保持在 1.4 mM。在反应 48 小时后,以提供的 l-薄荷醇为基础生成的 α-MenG摩尔转化率最高为 30.7%。