钙和钒离子对钒-溴过氧化物酶催化H_2O_2氧化环己烯反应的影响

Effects of Calcium and Vanadium Ions on the Epoxidation of Cyclohexene with H_2O_2 Catalyzed by Vanadium Bromoperoxidase

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1.0mmol/L钒离子和1.0mmol/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4.79g/(h·L),对H2O2的收率为74%,均比文献最高值提高了78%.

Vanadium bromoperoxidase （V-BPO） from a marine macro-alga Corallina officinalis can catalyze the epoxidation of cyclohex-ene 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 productivity. 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.