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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (7): 823-826. 上一篇    下一篇

研究简报

少量离子液体对有机相R.miehei脂肪酶催化合成辛酸戊酯的影响

吴红平 方云 万会达 夏咏梅   

  1. 江南大学化学与材料工程学院
  • 投稿日期:2007-08-08 修回日期:2007-10-10 发布日期:2008-04-14
  • 通讯作者: 夏咏梅

Effect of Ionic Liquid on Lipase-catalyzed Synthesis of Amyl Caprylate in Organic Solvent

  

  • Received:2007-08-08 Revised:2007-10-10 Published:2008-04-14

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502

被引次数

15

研究了疏水性离子液体[BMIM][PF6]对脂肪酶R. miehei有机相催化合成辛酸戊酯反应的影响，并结合荧光发射光谱分析R. miehei构象变化与酶活性表达的关联。结果表明，该酯化反应在饱和烷烃中的初速度比在芳烃中的大，且当溶剂logP为1.5～3.5时，反应初速度随logP的增加而降低。在不同有机溶剂中，加入占辛酸质量1%的[BMIM][PF6]均导致反应初速度降低15%左右，降低幅度几乎不与溶剂种类有关。表明[BMIM][PF6]对该反应的影响与所在溶剂系统无关，而只与离子液体的加入有关。[BMIM][PF6]加入量为辛酸质量1%～3%时，以壬烷为溶剂时的反应初速度随[BMIM][PF6]加入量的增加而降低，进一步表明离子液体的加入量是影响反应初速度的重要因素。荧光光谱分析表明，酶活性的表现与酶分子的构象变化有一定的相关性。

关键词: 脂肪酶, 离子液体, 反应初速度, 酯化

Effect of hydrophobic [BMIM][PF6] on enzymatic synthesis of amyl caprylate catalyzed by lipase from R. miehei in organic solvent was studied. The relevance of the enzyme activity and the conformational changes were investigated by means of the fluorescence spectra of the enzyme. It was found that the lipase-catalyzed esterification in alkanes is more efficient than in aromatic hydrocarbons. The initial reaction rate decreases with the increase of logP when logP was 1.5~3.5. [BMIM][PF6] (1% of caprylic acid, w/w) induced a 15% decrease in the initial reaction rate for all assayed reactions executed in different organic solvents, which indicates that the effect of [BMIM][PF6] on the reaction is only related to its addition rather than the solvent it was with. Further more, the initial reaction rate decreased with the increase of the dosage of [BMIM][PF6] (1%~3% of caprylic acid, w/w) employed in the reactions carried out in nonane. The fluorescence spectra analysis indicates that the conformation change coordinates to the enzyme activity.

Key words: lipase, ionic liquid, initial rate, esterification