Chemical Diversity Investigation of Hepatotoxic Pyrrolizidine Alkaloids in Qianliguang (Senecio scan

Objective: Qianliguang (Senecio scandens) is a common Chinese medicinal herb. Qianliguang-containing herbal proprietary products are registered as over-the-counter remedies in China and exported to Western countries. The presence of hepatotoxic pyrrolizidine alkaloids (PAs) has raised concerns about the safety of using Qianliguang and its products. The present study aims at investigation of different types of PAs present in Qianliguang collected from representative locations in China. Methods: In this study, a simple but specific UHPLC-QTOF-MS method for the determination of toxic PAs was developed, based on the characteristic fragment ions specific to different types of PAs. It was successfully applied for the identification and distinguishing of PAs present in Qianliguang and related Senecio species growing in different locations of China. Results: Significant diversity of the PA types and quantities were revealed among the samples tested. The estimated total amounts of toxic PAs in three of the samples exceed the toxic limits of PA intake restricted by WHO, demonstrating the timely and highly demand for regulating both types and quantities of PAs present in Qianliguang. Conclusions: This study provides the methodology for simultaneous identification and quantification of PAs present in herbs without requiring corresponding standards, which could be further used for more systematic investigations of the PA distribution in Qianliguang and other PA-containing herbs.