The First Kynurenine3‑Monooxygenase Activatorwith an Undescribed Skeleton Provides Insight into the ToxicologicalMechanism of Gelsemium elegans

Liquid chromatography–mass spectrometry-guided phytochemical isolation led to the discovery of four dimeric Gelsemium alkaloids, gelselegangmines A–D (<b>1</b>–<b>4</b>) from Gelsemium elegans. These dimers were connected by pyrrole rings. Their formation mechanism may include oxidation, hydrolysis, nucleophilic addition, etc. Bioactivity screening and verification disclosed alkaloid <b>2</b> as the first kynurenine 3-monooxygenase activator, providing insight into the toxicological mechanism of this famous plant.