Objectives To develop a high-performance liquid chromatography (HPLC) tandem
mass spectrometry method for screening and identifying the multiple constituents in
the complex Chinese materia medica (CMM) formulation Sini Decoction. Methods The
chemical constituents in Sini prescription as an entirety were isolated and analyzed by
HPLC coupled with electrospray ionization ion-trap mass spectrometry (ESI-IT-MS) in
order to clarify the chemical components of Sini Decoction and explore the chemical
methods of studying CMM prescriptions. Results Twenty-five compounds were
isolated from the water extract of this decoction. Through chemical and spectral
analyses, the structures of 20 compounds were elucidated, including 15 flavonoids,
one triterpene, two coumarins, and two other types of compounds. By using
HPLC-DAD-MSn technique, the MSn cleavage behaviors of the flavonoids have been
summarized as well as the origin of the isolated compounds was assigned. Conclusion
The phytochemical compositon of Sini prescription is tentatively characterized by
HPLC-DAD-ESI-IT-MSn. The results of the experiments demonstrate that the
combination of HPLC and ESI-MSn is a sensitive and effective tool for rapidly
investigating the complex CMM formulations.