玄参中β葡萄糖苷酶活性测定条件及干燥过程中酶活性变化的研究(1)
[摘要]采用pNPG法测定玄参中β葡萄糖苷酶的活性，通过单因素及均匀设计实验对提取液的种类、反应体系、反应时间、温度、以及底物浓度等提取条件与反应条件进行了筛选，并在此基础上测定了新鲜玄参在40～100 ℃干燥温度中酶活性的变化。结果显示，柠檬酸磷酸缓冲液提取效果较好，50 ℃环境下反应30 min时酶促反应产生的吸光度最大，均匀设计实验确定最佳提取液pH 70、酶反应体系pH 60、底物浓度20 mmol·L-1。酶活性变化受干燥温度和失水率影响，60～100 ℃干燥过程中温度升高，随着失水率加快酶活性迅速下降，而40，50 ℃干燥过程中一定的酶活性始终存在。该研究为环烯醚萜苷类水解机制和最佳干燥工艺的研究奠定了理论基础。
[关键词]玄参； β葡萄糖苷酶； 提取条件； 活性测定条件
Investigate optimum conditions and determinate changes of βglucosidase
, http://www.100md.com
activity in Scrophularia root under different drying conditions
YU Huanhuan1， YOSHIMITSU Michiyo1， XU Xiuying1， ZHENG Yimin1， LI Longyun2*
(1. School of Pharmacy and Bioengineering， Chongqing University of Technology， Chongqing， 400054；
2. Chonqing Academy of Chinese Materia Medica， Chongqing， 400065)
[Abstract]To explore the optimum conditions of βglucosidase 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 βglucosidase activity in Scrophularia root were detected at the drying temperature of 40100 ℃ 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 70； enzymatic reaction system pH 60； substrate concentration 20 mmol·L1 The change of enzyme activity was affected by drying temperature and water loss rate In the drying temperature of 60100 ℃， 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
, http://www.100md.com
[Key words]Scrophularia root； βglucosidase activity； extraction conditions； activity testing conditions
玄參为玄参科植物Scrophulariacese玄参Scrophularia ningpoensis Hemsl的干燥根，是具有凉血滋阴、泄火解毒等功效的传统中药材[1]，主要成分为哈巴苷、哈巴俄苷、桃叶珊瑚苷与O甲基梓醇等环烯醚萜苷类。环烯醚萜苷类极易氧化或水解，并且环烯醚萜类苷键水解断裂和氧化聚合所生成的苷元很不稳定，同时引起颜色的变化[23]。在中药材干燥加工过程中，酶活性的变化是引起药材性味及化学成分发生转化的重要原因。据文献报道，在玄参不同炮制方法的研究中发现，水解酶活性对玄参中主要成分哈巴俄苷的含量具有潜在影响[45]，哈巴俄苷在干燥过程中可能使其肉桂酰基水解， 产生哈巴苷和肉桂酸[6]。另有研究发现哈巴苷、哈巴俄苷、桃叶珊瑚苷等环烯醚萜类化合物经β葡萄糖苷酶水解后具有抗炎活性[79]。可见玄参干燥过程中药材内在成分变化复杂，从而影响外观颜色以及药物功效。目前对于酶活性影响环烯醚萜苷水解机制的实验数据尚未见报道，阐明药材初加工过程中影响成分变化的机制，涉及到对干燥环境的合理控制，对提高玄参药材质量和稳定性具有重要意义。, http://www.100md.com(喻欢欢 吉光见稚代 胥秀英 郑一敏 李隆云)
[关键词]玄参； β葡萄糖苷酶； 提取条件； 活性测定条件
Investigate optimum conditions and determinate changes of βglucosidase
, http://www.100md.com
activity in Scrophularia root under different drying conditions
YU Huanhuan1， YOSHIMITSU Michiyo1， XU Xiuying1， ZHENG Yimin1， LI Longyun2*
(1. School of Pharmacy and Bioengineering， Chongqing University of Technology， Chongqing， 400054；
2. Chonqing Academy of Chinese Materia Medica， Chongqing， 400065)
[Abstract]To explore the optimum conditions of βglucosidase 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 βglucosidase activity in Scrophularia root were detected at the drying temperature of 40100 ℃ 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 70； enzymatic reaction system pH 60； substrate concentration 20 mmol·L1 The change of enzyme activity was affected by drying temperature and water loss rate In the drying temperature of 60100 ℃， 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
, http://www.100md.com
[Key words]Scrophularia root； βglucosidase activity； extraction conditions； activity testing conditions
玄參为玄参科植物Scrophulariacese玄参Scrophularia ningpoensis Hemsl的干燥根，是具有凉血滋阴、泄火解毒等功效的传统中药材[1]，主要成分为哈巴苷、哈巴俄苷、桃叶珊瑚苷与O甲基梓醇等环烯醚萜苷类。环烯醚萜苷类极易氧化或水解，并且环烯醚萜类苷键水解断裂和氧化聚合所生成的苷元很不稳定，同时引起颜色的变化[23]。在中药材干燥加工过程中，酶活性的变化是引起药材性味及化学成分发生转化的重要原因。据文献报道，在玄参不同炮制方法的研究中发现，水解酶活性对玄参中主要成分哈巴俄苷的含量具有潜在影响[45]，哈巴俄苷在干燥过程中可能使其肉桂酰基水解， 产生哈巴苷和肉桂酸[6]。另有研究发现哈巴苷、哈巴俄苷、桃叶珊瑚苷等环烯醚萜类化合物经β葡萄糖苷酶水解后具有抗炎活性[79]。可见玄参干燥过程中药材内在成分变化复杂，从而影响外观颜色以及药物功效。目前对于酶活性影响环烯醚萜苷水解机制的实验数据尚未见报道，阐明药材初加工过程中影响成分变化的机制，涉及到对干燥环境的合理控制，对提高玄参药材质量和稳定性具有重要意义。, http://www.100md.com(喻欢欢 吉光见稚代 胥秀英 郑一敏 李隆云)