RESUMO
Objective: To rapidly recognize and identify phenanthrenes in Juncus effusus and J. setchuensis. Methods: HPLC-ESI-MS method was used to investigate the ESI-MS characteristics of those phenanthrenes, to screen, and to identify phenanthrenes in J. effusus and J. setchuensis. Results: Under negative mode, phenanthrenes were inclined to loss two hydrogens, which presumably caused by the cyclization of vinyl and aromatic ring; Furthermore, the loss of C=O could be also observed. Fragmentation pathway of phenanthrenes in ESI as a negative ion mode was summarized. Twenty-one phenanthrenes were rapidly detected from the extracts of J. effusus and J. setchuensis. Among them, six compounds were accurately identified by comparison with reference substances; The structures of five compounds were inferred according to their MS spectrum and polarity. Conclusion: HPLC-ESI-MS provides not only a new technique for the rapid identification of phenanthrenes from complex matrix, but also an effective method for the target separation of constituents in Chinese materia medica.