微波辐射-酶耦合催化(MIECC)戊醇同分异构体与n-辛酸的酯化反应

Esterification between Amyl Alcohol Isomers and n-Caprylic Acid under Microwave Irradiation-Enzyme Coupling Catalysis (MIECC)

以戊醇同分异构体与n 辛酸为反应底物 ,比较在三种模式下进行的非水相酶催化酯化反应 :( 1)在线微波辐射 (MI)模式 ;( 2 )常规加热 (CH )模式 ;( 3 )离线微波预辐射酶 +常规加热 (pre MI +CH)模式 ,以揭示微波辐射 -酶耦合催化(MIECC)的耦合效应 .实验结果表明 ,MIECC在提高酯化反应初速率方面表现出明显的耦合效应 ,可加快反应初速率 2 .5～4.5倍 .醇结构对MIECC有影响 ,在反应初速率及平衡产率方面均遵循伯醇 >仲醇 >叔醇的规律 .MI模式或pre MI +CH模式对酶均有激活作用 ,经微波预辐射的酶产生某种记忆效应 。

The enzymatic esterification between amyl alcohol isomers and n-caprylic acid was investigated in the following three ways to reveal the potential coupling mechanism of microwave irradiation-enzyme coupling catalysis (MIECC). That is, (1) MI manner: on-line microwave irradiation with 2450 MHz emission frequency and constant output power, (2) CH manner: conventional isothermal heating and (3) pre-MI + CH manner: enzyme pre-treated by microwave irradiation followed by catalysis under conventional heating. The obvious MIECC effect on increasing initial reaction rate 2.5 similar to 4.5 times but less influence on shifting reaction equilibrium was observed. The structure of amyl alcohol affects both the initial reaction rate and the ultimate yield of amyl n-caprylate in the following sequence: primary alcohol > secondary alcohol > tertiary alcohol. Increment of microwave power shows some effect on the initial reaction rate of esterification. but the short intermittence of MI/cooling seems more favorable to MIECC in reaction rate. The experimental results show that, no matter how MI or pre-MI + CH manner can activate enzymes and especially the enzyme that undergoes pre-MI can keep the stimulated activity during following reaction due to some memory function of enzyme to pre-MI.