非水相酶催化合成D-异抗坏血酸-6-硬脂酸酯的工艺研究

摘要

One-factor-at-a-time and orthobonal array design methods are employed to study the esterification conditions,such as the kinds of lipases,organic solvent,enzyme load,temperature,substrate molar ratio and the addition of molecular sieves for lipase catalyzed of D-isoascorbyl Stearate(D-IS)from D-isoascorbic acid and Stearate acid.The result shows that 72.58％ of conversion rate was finally obtained under the optimized condition:isoascorbic-to-Stearate acid molar ratio of 1:4,reaction temperature of 50oC,enzyme load of 20％(w/w)when the reaction parameters are set as:80 g/L of molecular sieves content,200 rpm speed for 24-h reaction time in tert-butyl alcohol.%以D-异抗坏血酸(EA)和硬脂酸为原料,利用单因素试验和正交试验,研究脂肪酶的种类、有机溶剂、酶量、温度、底物浓度和分子筛的用量对酶促酯化反应合成D-异抗坏血酸-6-硬脂酸酯(D-IS)的影响,并确定了其最佳反应条件.结果表明,在以叔丁醇为反应介质,固定化脂肪酶Novozym 435为催化剂的反应体系中,合成D-异抗坏血酸-6-硬脂酸酯的最佳反应条件为:底物摩尔比(EA:硬脂酸)为1∶4,温度为50℃,酶用量为20％,分子筛浓度为80g/L,摇床转速200rpm,反应24h后产物D-异抗坏血酸-6-硬脂酸酯的转化率为72.58％.