Cyclization reactions that create complex polycyclic scaffolds are hallmarks of alkaloid biosynthetic pathways. We present the discovery of three homologous cytochrome P450s from three monoterpene indole alkaloid-producing plants (Rauwolfia serpentina, Gelsemium sempervirens and Catharanthus roseus) that provide entry into two distinct alkaloid classes, the sarpagans and the β-carbolines. Our results highlight how a common enzymatic mechanism, guided by related but structurally distinct substrates, leads to either cyclization or aromatization.

中文翻译：

---

Sarpagan桥酶具有底物控制的环化和芳构化模式

产生复杂多环支架的环化反应是生物碱生物合成途径的标志。我们从三种产生单萜吲哚生物碱的植物（ Rauwolfia serpentina、Gelsemium sempervirens和Catharanthus roseus ）中发现了三种同源细胞色素 P450，它们提供了两种不同的生物碱类别，即 sarpagans 和 β-咔啉。我们的研究结果强调了一种常见的酶机制如何在相关但结构不同的底物的指导下导致环化或芳构化。