近临界水中薯蓣皂苷的水解反应

Hydrolysis of Dioscin to Diosgenin in Subcritical Water

在近临界水中研究了薯蓣皂苷水解成薯蓣皂苷元的工艺和反应动力学,分别考察了反应温度、压力、时间等因素对薯蓣皂苷元收率的影响。实验结果表明,近临界水解法的较佳工艺条件为260℃,25 MPa,反应10 min。在此条件下,薯蓣皂苷元收率为1.46%。动力学研究结果表明,薯蓣皂苷在近临界水中水解是一级反应,活化能为76.7 kJ/mol,指前因子k0为5.99×104s-1。

Diosgenin was an important raw material for steroid hormone and steroid contraception medicine synthesis. Usually, it was produced from dioscin hydrolysis in acid solution. But this process consumed a large quantity of water and polluted environment seriously. Subcritical water had the advantages of organic solvent, acid catalysis, chemical reaction acceleration and environmental friendship. The reaction conditions and chemical dynamics of diosgenin production from dioscin hydrolysis in subcritical water without catalyst were studied. The effects of reaction temperature, reaction pressure and reaction time on the yield of diosgenin were investigated respectively. The experimental results showed that the optimal reaction conditions were 25 MPa, 260 ℃ and reaction time 10 min. Under such reaction conditions, 1.46% yield of diosgenin was obtained. The dynamic experimental results showed that dioscin hydrolysis was first order reaction, the activation energy was 76.7 kJ/mol and frequency factor ko was 5.99N10^4 s^-1.