固定化脂肪酶合成肉豆蔻酸异丙酯的研究

采用固定化脂肪酶(Novozym 435)在有机溶剂体系中催化肉豆蔻酸和异丙醇酯化合成了肉豆蔻酸异丙酯.研究了各种因素如有机溶剂种类、反应物摩尔比、反应温度及酶用量等因素对酯化率的影响.结果表明,肉豆蔻酸异丙酯合成的较佳条件为:1.14 g肉豆蔻酸,0.45 g异丙醇,0.02 g Novozym 435,10 mL石油醚(其中加入0.5 g 3A分子筛吸水),在55℃下振荡反应4 h,酯化率为99.2%(肉豆蔻酸可基本完全转化为肉豆蔻酸异丙酯).实验过程中固定化酶稳定性较好,可连续使用7批左右.

Study of enzymatic synthesis of isopropyl myristate with immobilized lipase

Isopropyl myristate was synthesized by the esterification of myristic acid with isopropanol using immobilized lipase (Novozym 435) as catalyst and an organic solvent as a reaction medium. The effects of solvent, molar ratio of substratcs, reaction temperature and dosage of the catalyst were investigated. Molecular sieve 3A was added into the reaction system to remove the water produced during the esterification and increased dramatically the esterification yield to make myristic acid react thoroughly. The optimized reaction conditions were as follows: 1.14 g myristic acid,0.45 g isopropanol,0. 02 g Novozym 435,0. 5 g 3A molecular sieve, 10 mL petroleum ether, at 55 ℃ for 4 h under oscillation condition. As the reaction process was stopped, 99. 2% of myristic acid was converted into isopropyl myristate. The immobilized lipase can be reused for at least 7 times.