二步法制备稀有人参皂苷Rh1组异构体

Preparation of Rare Ginsenoside Rh1 Group Isomers by Two-step Method

本论文以制备人参皂苷Rh1为目标,选择三醇类人参皂苷Re为底物,采用酶转化和金属离子催化联用的二步法催化转化,研究了各步骤中的催化反应条件,并对产物进行了纯化和组成分析。结果表明:Absidia sp.P39r菌株产酶能催化转化Re生成Rg1,确定其最佳反应条件为:缓冲液pH5.0,反应温度40℃,底物浓度1.2%,反应时间16 h,乙醇浓度10%,在此反应条件下得到的Rg1质量分数最高,为70.5%。然后以Rg1为底物,确定在乙醇-水体系下Fe3+的催化反应产物20(S,R)-Rh1的质量分数最高,催化反应条件优化结果为:乙醇浓度50%,反应温度50℃,底物浓度1.7%,Fe3+溶液反应浓度1.4 mol/L,反应时间14 h,20(S,R)-Rh1的质量分数高达61.83%,Rk3、Rh4的质量分数之和为27.34%。在上述条件下将20 g人参皂苷Re与酶液反应,反应结束后用AB-8大孔吸附树脂分离干燥得到含有Rg1的产物14.1 g。再取10.2 g反应得到的Rg1与Fe^3+溶液反应,干燥后最终得到的人参皂苷Rh1组异构体质量为8.18 g,得率为80.2%,其中20(S)-Rh1,20(R)-Rh1,Rk3和Rh4的含量分别为37.71%,24.12%,7.27%,20.07%。

The aim of this thesis was to prepare ginsenoside Rh1 by catalytic transformation of protopanaxatriol type saponin Re with two-step method including enzymatic conversion and metal ion catalysis. The catalytic reaction conditions in each step were researched,and the products were purified and analyzed.The results showed that,Absidia sp.P39 r strain could catalyze Re to Rg1,the optimum reaction conditions were determined as: Buffer pH5.0,reaction temperature 40 °C,substrate concentration1.2%,reaction time 16 h,ethanol concentration 10%. Under these conditions,the mass fraction of Rg1 obtained was the highest,up to 70.5%.Next,Rg1 was used as the substrate,the mass fraction of 20( S,R)-Rh1 was determined to be the highest in reaction conditions under metallic ion Fe3+catalysis.The optimum reaction conditions were as follows: Ethanol concentration50%,reaction temperature 50 °C,substrate concentration 1.7%,Fe3+solution concentration 1.4 mol/L,reaction time 14 h,the mass fraction of 20( S,R)-Rh1 was 61.83%,and the sum mass fractions of Rk3 and Rh4 were 27.34%. Under the above conditions,20 g ginsenoside Re was reacted with the enzyme solution. And after the reaction was completed,14.1 g Rg1-containing product was obtained by separation with AB-8 macroporous adsorption resin and dried.Then,10.2 g Rg1 obtained by the reaction was reacted with Fe3+solution.After drying,the mass of the final ginsenoside Rh1 group isomers was 8.18 g,with a conversion rate of 80.2%,in which the contents of 20( S)-Rh1 was 37.71%,20( R)-Rh1 was 24.12%,Rk3 was 7.27%,Rh4 was 20.07%.