利用一种耐热耐糖β-葡萄糖苷酶制备黄芩素的研究  

Preparation of baicalein using thermophilic and sugar-tolerant β-glucosidase

作　　者：李石平[1,2,3] 温建辉[1,2,3] 赵祎武[1,2,3] 黄文哲[1,2,3] 裴建军[4] 王振中[1,2,3] 赵林果[4] 萧伟[1,2,3] 

机构地区：[1]江苏康缘药业股份有限公司,江苏连云港222001 [2]中药制药过程新技术国家重点实验室,江苏连云港222001 [3]中药提取精制新技术重点研究室,江苏连云港222001 [4]南京林业大学化学工程学院,江苏南京210037

出　　处：《中国中药杂志》2015年第23期4616-4622,共7页China Journal of Chinese Materia Medica

基　　金：国家"重大新药创制"科技重大专项(2013ZX09402203)

摘　　要：对利用一种耐热耐糖β-葡萄糖苷酶水解黄芩苷制备黄芩素进行了研究。该酶催化黄芩苷转化为黄芩素的反应能在醋酸-醋酸钠缓冲液中良好地进行,酶的最适p H 5.5,最适反应温度85℃,温度在85℃以下,p H 5~7.5酶的稳定性良好。酶的最大反应速率Vmax为0.41 mmol·L^(-1)·min^(-1),米氏常数Km为3.31 mmol·L^(-1)。不同的金属离子对酶的活性有不同的影响,醋酸-醋酸钠缓冲液中的Na+对酶有活化作用。反应体系中葡萄糖醛酸浓度低于0.6 mol·L-1时,对酶有活化作用,当单糖浓度大于0.6 mol·L^(-1)时,对酶有抑制作用,当单糖浓度达到1.2 mol·L^(-1)时,酶活抑制率为50%,糖耐受性较好。通过实验得出较佳反应条件为黄芩苷-酶液1 g∶0.2 m L,pH 5.5的醋酸-醋酸钠缓冲液,反应时间为10 h时,反应温度为85℃,酶解率可达97%。The reaction conditions of baicalin hydrolyzed into baicalein by a kind of thermophilic and sugar-tolerant β-glucosidase were studied in this paper. The β-glucosidase could catalyze baicalin into baicalein well in the acetic acid-sodium acetate buffer. The optimal enzyme activity was at 85 ℃ and p H 5. 5. The enzyme was stable at the temperature less than 85 ℃ and p H range of 5-7. 5.The maximum reaction rate Vmaxand michaelis constant Kmwere 0. 41 mmol·L^（-1）·min^（-1） and 3. 31 mmol·L^（-1） respectively. Different metal ions had different effects on the activity of enzyme. Na＋existing in acetic acid-sodium acetate buffer had an activation effect on enzyme. The enzyme activity was enhanced by the concentrations of glucose below 0. 6 mol·L^（-1）,and was gradually inhibited when monosaccharide concentration was over 0. 6 mol·L^（-1）. When the monosaccharide concentration reached 1. 2 mol·L^（-1）,the inhibition rate of enzyme activity was about 50%,which showed good glucose tolerance. The good reaction conditions through the experiment have been determined as follows,the substrate∶ enzyme dose was 1 g∶ 0. 2 m L,acetic acid-sodium acetate buffer pH 5. 5,reaction temperature 85 ℃,reaction time 10 h,and the enzymatic hydrolyzation ratio could reach 97%.

关 键 词：耐热 耐糖 Β-葡萄糖苷酶 黄芩苷 黄芩素 

分 类 号：R283[医药卫生—中药学]