The First Kynurenine 3-Monooxygenase Activator with an Undescribed Skeleton Provides Insight into the Toxicological Mechanism of Gelsemium elegans

Liquid chromatography-mass spectrometry-guided phytochemical isolation led to the discovery of four dimeric Gelsemium alkaloids, gelselegangmines A-D (1-4) 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 2 as the first kynurenine 3-monooxygenase activator, providing insight into the toxicological mechanism of this famous plant.