Yu Huan-Huan, Yoshimitsu Michiyo, Xu Xiu-Ying, Zheng Yi-Min, Li Long-Yun
School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 400054.
Chonqing Academy of Chinese Materia Medica, Chongqing, 400065.
Zhongguo Zhong Yao Za Zhi. 2017 Jan;42(2):274-279. doi: 10.19540/j.cnki.cjcmm.20161222.049.
To explore the optimum conditions of β-glucosidase activity in Scrophularia root by using pNPG method. The extraction conditions and reaction conditions (such as extraction liquid type, reaction system, reaction time, temperature, and substrate concentration) were screened by using monofactorial experiment and homogeneous design. Then the changes of β-glucosidase activity in Scrophularia root were detected at the drying temperature of 40-100 ℃. The results showed that citric acid phosphate buffer had better extraction effect, and the maximum absorbance produced by enzymatic reaction was present at 50 ℃ environment after reaction for 30 min. Homogeneous design experiment determined that the optimal conditions were as follows: optimal extraction liquid pH 7.0; enzymatic reaction system pH 6.0; substrate concentration 20 mmol•L⁻¹. The change of enzyme activity was affected by drying temperature and water loss rate. In the drying temperature of 60-100 ℃, the enzyme activity was reduced rapidly with the increase in water loss rate, while the activity was seen even with 0% of water at 40 and 50 ℃. This study has laid the theoretical foundation for research of hydrolysis mechanism of iridoid glycosides and optimum drying process.
采用对硝基苯-β-D-吡喃葡萄糖苷（pNPG）法探究玄参中β-葡萄糖苷酶活性的最佳条件。通过单因素试验和均匀设计筛选提取条件和反应条件（如提取液类型、反应体系、反应时间、温度和底物浓度）。然后在40 - 100℃干燥温度下检测玄参中β-葡萄糖苷酶活性的变化。结果表明，柠檬酸磷酸缓冲液具有较好的提取效果，酶促反应在50℃环境下反应30 min后产生的最大吸光度。均匀设计试验确定最佳条件如下：最佳提取液pH 7.0；酶促反应体系pH 6.0；底物浓度20 mmol•L⁻¹。酶活性变化受干燥温度和失水率影响。在60 - 100℃干燥温度下，酶活性随失水率增加而迅速降低，而在40℃和50℃时，即使失水率为0%仍有活性。本研究为环烯醚萜苷水解机理及最佳干燥工艺研究奠定了理论基础。
