钙和钒离子对钒-溴过氧化物酶催化 H2O2 氧化环己烯反应的影响

 在溴化钾存在下, 大型海洋藻类珊瑚藻的钒-溴过氧化物酶 (V-BPO) 可在常温下催化 H₂O₂ 环氧化环己烯生成环氧环己烷. 通过用含 1.0 mmol/L 钒离子和 1.0 mmol/L 钙离子的缓冲溶液透析 V-BPO, 用恒流泵向反应体系中连续添加 H₂O₂, 并优化其它反应条件, 可提高该催化反应时空收率. 在优化的反应条件下, 产物环氧环己烷的时空收率为 4.79 g/(h•L), 对 H₂O₂ 的收率为 74%, 均比文献最高值提高了 78%.

Effects of Calcium and Vanadium Ions on the Epoxidation of Cyclohexene with H2O2 Catalyzed by Vanadium Bromoperoxidase

Vanadium bromoperoxidase (V-BPO) from a marine macro-alga Corallina officinalis can catalyze the epoxidation of cyclohexene in the presence of KBr to form epoxycyclohexane using H₂O₂ as the oxidant. A process intensification strategy has been developed by the integration of V-BPO pretreatment, continuous feeding of H₂O₂, and optimizing reaction conditions in order to improve the epoxidation pro-ductivity. The BPO activity and thermostability increased significantly when the V-BPO solution was dialyzed with a buffer containing 1.0 mmol/L vanadium ion and 1.0 mmol/L calcium ion. The apparent enzyme activity was improved when the H₂O₂ was fed continuously using a constant flow pump. When combined with the optimal reaction conditions (including buffer, pH, temperature, enzyme concentration, and KBr and H₂O₂ concentrations), the space-time yield of epoxycyclohexane and its yield to hydrogen peroxide reached 4.79 g/(L•h) and 74%, respectively. These values are 78% increasing than the highest values reported previously.