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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (2): 245-250. 上一篇    下一篇

研究论文

改性Ultrastable-Y分子筛固定化对非水相中脂肪酶拆分(R,S)-2-辛醇的影响

戴大章*，夏黎明   

  1. (浙江大学化学工程与生物工程学系 杭州 310027)
  • 投稿日期:2007-03-20 修回日期:2007-06-08 发布日期:2008-01-28
  • 通讯作者: 戴大章

Effect of Immobilization by Modified Ultrastable-Y Molecular Sieve on the Resolution of (R,S)-2-Octanol in Nonaqueous Media by Lipase

DAI Da-Zhang*; XIA Li-Ming   

  1. (Department of Chemical Engineering and Bioengineering, Zhejiang University, Hangzhou 310027)
  • Received:2007-03-20 Revised:2007-06-08 Published:2008-01-28
  • Contact: DAI Da-Zhang

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采用改性Ultrastable-Y分子筛固定Penicillium expansum PED-03 脂肪酶(PEL), 利用固定化PEL在非水相中对(R,S)-2-辛醇进行手性拆分, 考察了改性Ultrastable-Y分子筛固定化处理对PEL催化性能的影响. 结果表明, 与游离PEL及经其它载体固定化的PEL相比, 改性Ultrastable-Y分子筛固定的PEL所催化的拆分反应的转化率(c)和对映体过量值(ee)以及对映体选择性(E)均得到了较大提高. 经固定化处理后, PEL的最适反应温度明显升高, 适宜反应温度范围变宽, 其稳定性也得到了明显改善, 而适宜反应pH值则具有“记忆”性. 在间歇式反应器中利用Ultrastable-Y分子筛固定化PEL对(R,S)-2-辛醇进行手性拆分, 50 ℃反应24 h转化率(c)可达理论值的97.68%, 对映体过量值(ee)可达98.75%. 连续8批拆分反应的结果表明: 改性Ultrastable-Y分子筛固定化脂肪酶催化效率高、立体选择性强(平均E 值＞460), 且催化性能稳定, 显示了该固定化酶在(R,S)-2-辛醇的手性拆分方面具有良好的应用前景.

关键词: 改性分子筛, 固定化脂肪酶, 拆分, 2-辛醇, 催化性能

The lipase from Penicillium expansum PED-03 (PEL) was immobilized into a modified ultrastable-Y molecular sieve and the resolution of (R,S)-2-octanol was carried out in a bioreactor in nonaqueous media by the immobilized lipase to investigate the effect of immobilization on the catalytic property of PEL duing the enzymatic reaction. It was found that the conversion (c), enantiomeric excess (ee), and enantioselectivity (E) of the resolution catalyzed by the PEL immobilized on the modified ultrastable-Y molecular sieve were much higher than those of the reaction catalyzed by free PEL and PEL immobilized on other supports. Being immobilized on the modified Ultrastable-Y molecular sieve, the lipase exhibited obvious activity in a wider pH range and at a much higher temperature than the free PEL, and showed a marked enhancement of stability against thermal inactivation, by which the suitable pH value of the buffer used for immobilization could be “memorized”. The conversion of the reaction catalyzed by PEL immobilized on the modified ultrastable-Y molecular sieve reached 97.68% of the theoretical value with excellent enantioselectivity (Average E of 8 batches ＞460) in nonaqueous media at “memorial” pH 9.5, 50 ℃ for 24 h, which showed a good application potential to the production of optically pure (R,S)-2-octanol.

Key words: modified ultrastable-Y molecular sieve, immobilized lipase, resolution, 2-octanol, catalytic property