利用乳液酶膜反应器拆分萘普生甲酯实验研究

Experimental study on resolution of naproxen methyl esters in an emulsion enzyme membrane reactor

利用乳液酶膜反应器进行外消旋萘普生甲酯的水解反应,以制备光学纯对映体(S)-萘普生,反应同时从膜透过侧收集产物,实现反应分离一体化。实验研究了固定酶前后膜传质阻力和反应过程的水相跨膜通量,考察了透过侧的产物浓度、反应器的转化率、产量和对映体选择性。结果表明:固定化酶引起的传质阻力远大于膜本身的阻力;透过侧的产物浓度与水相渗透通量密切相关,通量较低时,产物浓度较高;固定化酶的初始反应速率为3.660μmol/(h.g),为自由酶的20倍以上,固定化酶的对映体过剩值为99%—100%,远高于自由酶的选择性,表明该反应体系为脂肪酶催化拆分反应提供了良好环境。

The hydrolysis reaction of racemic naproxen methyl esters was carried out in emulsion enzyme membrane reactor to produce optical pure （S）-naproxen. The product was simultaneously separated and collected from the permeate side of the membrane during the reaction process, thus realizing the combination of reaction and separation in the system. The mass transfer resistance of membrane before and after the immobilization of enzyme as well as the permeation rate of aqueous phase through the membrane were studied experimentally. The product concentration in the permeate, conversion, production and enantioselectivity of the reactor were investigated. It shows that the mass-transfer resistance induced by immobilized enzyme is much higher than that of membrane itself. The concentration of （S）-naproxen is reversely correlated with the permeation rate of aqueous phase and lower permeation rate leads to higher product concentration. The initial reaction rate of immobilized Candida rugosa lipase （CRL） is 3. 660 p, mol/（ h g）, which is more than 20 times higher than that of free CRL. As high as 99% -100% of enantiomeric excess is achieved, which is much higher than that of free CRL. This suggests a favorable catalytic environment for lipase-catalytic resolution.