多元电解质对脂肪酶有机相拆分炔戊醇的激活

Multi-electrolytes activation of Lipase for 4-methylhept-4-en-1-yn-3-ol resolution in organic media

脂肪酶是一种应用节广泛的重要生物催化剂,提高脂肪酶在非天然环境中的催化性能逐步成为了一个研究热点。研究表明,某些电解质的加入可显著提高提脂肪酶在有机溶剂体系中的酶活和选择性。然而有关研究主要考察单一电解质的作用,且涉及的电解质种类较少,更为系统的研究未见报道。本文以洋葱假单胞菌脂肪酶(Pseudomonas cepacia lipase,即PcL)催化手性菊酯农药前体4-甲基庚-4-烯基-1-炔基-3-醇(炔戊醇)在甲苯中选择性转酯化为模型,系统考察了卤化物、硝酸盐、硫酸盐、磷酸盐等8类35种电解质单独以及多种电解质协同对PcL催化性能的影响。结果表明,NaF-Na2HPO4/NaH2PO4的二元电解质体系具有远高于任意单一电解质组分的性能,该体系使PcL活力提高23倍。进一步研究表明,这一电解质体系对PcL催化不同对映体转酯化的活力提高程度不同,从而将其对映体选择率(E值)由11提高到21。

Lipase was an important biological catalyst,which was widely applied in many areas,how to improve its catalytic performance in non-natural environment has become a research hot spot gradually. Studies showed that the specific activity and enantioselectivity of lipase could be improved remarkably by adding some electrolytes into reaction system. However,relevant researches mainly focused on the role of single electrolyte,report on the types of electrolytes involved was much less,and further systematic research has not been reported yet. By utilizing Pseudomonas cepacia lipase (PcL) as the catalyst,the asymmetric transesterification resolution of 4-methylhept-4-en-1-yn-3-ol was conducted with the precursor of chiral chrysanthemum ester pesticides in hydrophobic organic media, the influences of 8 types,including halide,nitrate,sulfate,phosphate et al,35 kinds of electrolytes and their different combinations on PcL's catalytic performance were investigated systematically. The results indicate that the specific activity of PcL is 23 times higher than that of native lipase with synergistic effect of NaF,Na2HPO4 and NaH2PO4. Further study shows that the improvement of enantioselectivity has been achieved from 11 to 21,due to the different degree of activation of enantiomers by PcL.