摘要/Abstract

手性叔醇是合成药物和一些香料产品的非常重要中间体.芳樟醇是叔醇的一种，不同构型的芳樟醇具有不同的香气.因此如何研发合适的制备方法以获得高光学纯度的芳樟醇等叔醇是急需解决的技术问题.生物酶催化合成符合绿色化学的理念，但是由于叔醇化学结构中的空间位阻影响，使用生物酶催化的拆分反应制备高光学纯度的叔醇比较困难.对来自南极微生物的一个新的酯酶EST112-2进行了功能鉴定，并将其作为合成手性芳樟醇的生物催化剂.EST112-2可以通过不对称水解乙酸芳樟酯获得（S）-芳樟醇.对反应的pH、温度、共溶剂、底物浓度、催化剂用量以及反应时间等参数进行优化，EST112-2制备的（S）-芳樟醇的光学纯度大于66%，得率超过72%.EST112-2制备的（S）-芳樟醇的光学纯度要远远高于以往报道.
关键词: 生物催化, 南极微生物酯酶, 动力学拆分, 手性叔醇, (S)-芳樟醇
Chiral tertiary alcohols (TAs) are key building blocks for the synthesis of many crucial flavor compounds and pharmaceuticals. The two enantiomers of tertiary alcohol, linalool, differ in odor. So, sustainable strategies for the manufacture of optically pure TAs represented by linalool, are highly desirable. But the enzymatic synthesis of chiral tertiary alcohols through kinetic resolution was not easily achieved, possibly because of the steric hindrance from the chemical structures of tertiary alcohols. Herein, we identified and functionally characterized a new microbial esterase EST112-2 from the antarctic sediments and utilized esterase EST112-2 as a green biocatalyst in the synthesis of chiral tertiary alcohol (S)-linalool through asymmetric hydrolysis of racemic linalyl acetate. Parameters such as pH, temperature, co-solvents, substrate concentrations, enzyme loading and reaction time were optimized for the kinetic resolutions. Desired chiral product (S)-linalool was finally obtained with an enantiomeric excess of over 66% and a yield of over 72% after process optimization. The enantiomeric excess of (S)-linalool prepared by esterase EST112-2 was much higher than that from previous reports.
Key words: biocatalysis, antarctic microbial esterase, kinetic resolution, chiral tertiary alcohol, (S)-linalool


PDF全文下载地址:

点我下载PDF