The Final Steps in Pseudoiodinine Biosynthesis Feature Ring-Contractive N–N Bond Formation

作者：Lingyi Zhu, Xiaozheng Wang, Qing Shi, Tingting Huang, Ruihuan Yang, Lifang Zou, Gongyou Chen, Zixin Deng, Yu‐Cheng Gu, Ikuro Abe, Shuangjun Lin · 发表于：JACS Au · 年份：2025 · DOI：10.1021/jacsau.5c00358 · 被引用次数：4 · 研究领域：Metalloenzymes and iron-sulfur proteins、Synthesis and Catalytic Reactions、Biochemical and Molecular Research

High Resolution Image Download MS PowerPoint Slide Pseudoiodinine (PSD) is a N–N bond-containing natural product with profound antimicrobial and antifungal activities. In this work, we have completed the PSD biosynthetic pathway by explicating the final three steps, which involve an enigmatic N–N bond formation in a ring contraction process. As a starting material, 1,6-didesmethyltoxoflavin (1,6-DDMT) is sequentially methylated by PsdF and PsdA to give 5-methoxy-6-desmethyltoxoflavin (5-OCH 3 -6-DMT), which then undergoes oxidative decarboxylation for the ring-contractive N–N bond formation to generate the pyrazole ring catalyzed by PsdB, a novel vicinal oxygen chelate superfamily (VOC) protein. This is the first enzyme in the VOC family to catalyze such a reaction, providing new insight into N–N bond formation.