Photoenzymatic cascade reactions: Coupling photocatalytic in-situ generation of hydrogen peroxide with peroxidase-based enzymatic reactions

过氧酶催化各种氧化官能化反应，用于合成化学和药物构建块。与许多依赖辅因子的氧化还原酶不同，它们使用廉价且容易产生的过氧化氢(H_2O_2)作为辅助底物。然而，它们对过氧化氢的不稳定使得目前的应用相当复杂。在上一个项目中，我们可以证明多相光催化是一种很好的原位供应H_2O_2的工具。然而，通过光催化产生的羟基自由基的意外失活导致与替代的酶或电化学产生过氧化氢的方法相比，性能略低。随着详细动力学模型的建立、光催化剂的优化和固定化酶的使用，这一原理证明研究的进一步发展将进一步提高整个过程的效率。在该项目的后期阶段，将使用在线过氧化氢和产品分析来规范整个过程。最后，将使用更有效的光反应堆来强化这一进程，并将证明其可扩展性。

Peroxygenases catalyze a variety of oxyfunctionalizations for the synthesis of chemical and pharmaceutical building blocks. In contrast to many co-factor dependent Oxidoreductases they use the inexpensive and easily producible hydrogen peroxide (H2O2) as a cosubstrate. However, their instability against H2O2 currently makes the application rather complicated. In the previous project we could show that heterogeneous photocatalysis is an excellent tool for the adequate in-situ H2O2 supply. However, an unexpected inactivation through photocatalytically generated hydroxyl radicals leads to the somewhat lower performance compared to the alternative enzymatic or electrochemical H2O2 generation methods. A further development of this proof of principle study with the development of a detailed kinetic model, the optimization of the photocatalysts and the use of immobilized enzymes shall further improve the efficiency of the overall process. In a later stage of the project an online H2O2 and product analysis will be used to regulate the whole process. In the end more efficient photoreactors will be used for an intensification of the process and their scalability shall be demonstrated.