水相体系中固定化Acetobacter sp.CCTCC M209061细胞催化(S)-3-氯苯丙醇不对称合成

光学纯的3-氯苯丙醇是合成抗抑郁类药物的重要中间体。本论文报道了水相体系中固定化Acetobacter sp.CCTCC M209061细胞高效、高选择性地催化3-氯苯丙酮不对称还原为(S)-3-氯苯丙醇,采用聚乙烯醇与海藻酸钠的混合载体对醋酸杆菌细胞进行固定化,所得的固定化细胞的稳定性(热稳定性、p H稳定性及操作稳定性)均明显优于游离细胞。同时,固定化后的微生物细胞具有较好的重复利用性,连续反应3个批次后固定化细胞仍保留了80.0%以上的活性,而游离细胞的相对活性则小于20%。在所研究的体系中,葡萄糖为该反应的最佳辅底物,其最适浓度为50.0 mmol/L;该反应体系中的最适缓冲液p H值、反应温度、底物浓度分别为5.5、30℃和3.0 mmol/L。在此条件下,反应的初速度、产率以及产物的e.e.值依次为1.77 m M/h,88.9%和99.0%以上。

Asymmetric Synthesis of (S)-3-Chloro-1-phenylpropanol with Immobilized Acetobacter sp. CCTCC M209061 Cells in a Monophasic System

Optically pure 3-chloro-1-phenyl-1-propanol is an important intermediate for the synthesis of drugs for treating depression. In the present study, biocatalytic asymmetric reduction of 3-chloropropiophenone to (S)-3-chloro-1-phenyl-1-propanol with immobilized Acetobacter sp. CCTCC M209061 cells was successfully conducted in a monophasic aqueous system with high efficiency and selectivity. The immobilized Acetobacter sp. CCTCC M209061 cells exhibited higher stabilities (thermal, pH, and operational stability) than the free cells. In addition, the immobilized microbial cells exhibited a relatively good recyclability; the relative activity of immobilized cells remained over 80%, while that of the free cells under the same condition was less than 20%. In the studied system, glucose was the best co-substrate at an optimum concentration of 50 mmol/L. The optimum buffer pH, reaction temperature, and substrate concentration in this reaction system were 5.5, 30°C, and 3.0 mmol/L, respectively. Under the optimized reaction conditions, the initial reaction rate, yield, and product e.e. were 1.77 mM/h, 88.9%, and above 99.0%, respectively.