Structure characterization and identification steroidal saponins from Ophiopogon japonicus Ker-Gawler (Liliaceae) by high-performance liquid chromatography with ion trap mass spectrometry

Introduction – Steroidal saponins are the main active constituents in Ophiopogon japonicus Ker‐Gawler (Liliaceae). However, because of their high polarity, non‐chromophores and low content in plants, steroidal saponins are difficult to be isolated from O. japonicus by conventional phytochemical methods. Objective – To develop a sensitive and rapid approach towards the structural analysis of steroidal saponins using HPLC/ESI‐MSⁿ. Methodology – The fragmentation behaviors of six known steroidal saponins in negative ESI‐MSⁿ were used to deduce their mass spectral fragmentation mechanisms. By using HPLC/ESI‐MSⁿ, the important structural information on aglycone types, sugar types and saccharide sequences can be obtained. Results – According to the HPLC retention behaviour, the molecular structural characteristics provided by multistage mass spectrometry spectra and the literature, a total of 8 steroidal saponins were tentatively identified or characterized in O. japonicus rapidly. Conclusion – This work has shown that HPLC‐ESI‐MSⁿ may be used as an effective and rapid method for the characterization and identification of steroidal saponins from O. japonicus. Copyright © 2010 John Wiley & Sons, Ltd.