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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (10): 1010-1016. 上一篇    下一篇

研究论文

新型1,3-二丁基咪唑离子液体中脂肪酶催化折分(R,S)-1-苯乙醇

单海霞1，陆杨1，李在均*,1,2，李明1，陶丽华1，党渭铭2   

  1. (1江南大学化学与材料工程学院 无锡 214122)
    (2无锡信达胶脂材料有限公司 无锡 214142)
  • 投稿日期:2009-09-04 修回日期:2009-11-27 发布日期:2010-01-15
  • 通讯作者: 李在均 E-mail:zaijunli@263.net
  • 基金资助:

    国家自然科学基金(Nos.20771045 和20676052)、国家高技术计划“863” (2007AA10Z428)、浙江省自然科学基金(No.Y407321)和江苏省“青蓝工程”资助项目。

Resolution of (R,S)-1-Phenylethanol Catalyzed by Lipase in Novel 1,3-Dibutylimidazolium Ionic Liquid

Shan Haixia1 Lu Yang1 Li Zaijun*,1,2 Li Ming1 Tao Lihua1 Dang Weiming2   

  1. (1 School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122)
    (2 Wuxi Xinda Rosin & Ester System Co. Ltd, Wuxi 214142)
  • Received:2009-09-04 Revised:2009-11-27 Published:2010-01-15

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设计合成6种采用不同1,3-二丁基咪唑阳离子和六氟磷酸()或双三氟甲烷磺酰亚胺(TFSI－)阴离子的离子液体. 以脂肪酶催化拆分1-苯乙醇为模型反应, 分别考察介质、水含量和温度对反应的影响. 结果表明, 在1,3-二异丁基咪唑六氟磷酸盐([D(i-C4)Im][PF6])离子液体介质中酶的活性和反应性明显高于其它离子液体和正己烷. 因此, [D(i-C4)Im][PF6]被确定为反应介质. 在最佳条件下, 初始反应速率是1.93 μmol•mg－1•min－1, 1-苯乙醇的转化率达50%, 对映体过量值eep＞99%, 酶的半衰期为348 h, 酶重复使用10次后活性没有明显减少. 此外, 圆二色谱、内源荧光光谱和光学显微镜研究表明, 酶在[D(i-C4)Im][PF6]中保温6 d后氨基酸残基的裸露程度略有增加, 但其二级结构仍保持稳定, 且以天然的折叠球形态存在.

关键词: (R,S)-1-苯乙醇, 脂肪酶, 离子液体, 拆分

Six ionic liquids consisting different 1,3-dibutylimidazolium cation and hexafluorophosphate () or bis(trifluoromethanesulphonyl)imide (TFSI－) anion were designed and synthesized in the laboratory. The resolution of (R,S)-1-phenylethanol by Pseudomonas cepacial lipase was chosen as the model reaction to study on effects of the reaction medium, water content and temperature on the reaction. The results showed the activity of lipase in the ionic liquid 1,3-di-isobutylimidazolium hexafluorophosphate abbreviated as [D(i-C4)Im][PF6] has obviously better activity and reactivity than these in other ionic liquids and hexane. Accordingly, the ionic liquid [D(i-C4)Im][PF6] was chosen as the medium for the reaction. Under optimal condition, initial rate of lipase, the conversion of 1-phenylethanol, ee value of (R)-1-phenylethyl acetate and half life time of the lipase was 1.93 μmol•mg－1•min－1, 50%, 99% and 348 h, respectively. Moreover, circular dichroism, fluorescence spectrum and optical microscope analysis have demonstrated after the incubation of lipase in the ionic liquid [D(i-C4)Im][PF6] for 6 d the lipase exhibited an slightly increasing exposure level of amino-acid residue, however, its secondary structure is of excellent stability also and exists as its native ball enzyme conformation.

Key words: (R,S)-1-phenylethanol, lipase, ionic liquid, resolution