醇腈酶促不对称合成手性氰醇反应条件的研究

利用气相色谱手性分析，对醇腈酶促不对称合成手性氰醇中的pH值、温度、底物浓度和水含量对酶反应速度和非酶反应速度的影响作了研究。结果表明，上述因素对酶反应和非酶反应速度均有显著影响。在水含量较低的非水相酶反应体系中，pH值在4．0以下或反应温度为0－5℃时，非酶反应受到较大程度的抑制，而酶反应仍具有相对较快的反应速度，故可获得高光学纯度的产物。

Study on the Reaction Conditions for Asymmetric Synthesis of Optically Active Cyanohydrin Catalyzed by Oxynitrilase

The effects of pH value, temperature, substrate concentration and water content on the enzymatic and non-enzymatic reactions in the asymmetric synthesis of optically active cyanohydrin catalyzed by (R)-oxynitrilase from bitter almond were studied using GC chiral analysis. The conclusion is in non-aqueous organic solvent system with low water content, when pH value is below 4.0 or reaction temperature is 0～5 ℃, the non-enzymatic reaction is greatly inhibited, but oxynitrilase reaction still has relatively high rate. Therefore, the reaction can achieve high enantiomeric purity of the product.