Chemical investigation of saponins in different parts of Panax notoginseng by pressurized liquid extraction and liquid chromatography-electrospray ionization-tandem mass spectrometry.

A pressurized liquid extraction (PLE) and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for the qualitative determination of saponins in different parts of P. notoginseng, including rhizome, root, fibre root, seed, stem, leaf and flower. The samples were extracted using PLE. The analysis was achieved on a Zorbax SB-C18 column with gradient elution of acetonitrile and 8 mM aqueous ammonium acetate as mobile phase. The mass spectrometer was operated in the negative ion mode using the electrospray ionization, and a collision induced dissociation (CID) experiment was also carried out to aid the identification of compounds. Forty one saponins were identified in different parts of P. notoginseng according to the fragmentation patterns and literature reports, among them, 21 saponins were confirmed by comparing the retention time and ESI-MS data with those of standard compounds. The results showed that the chemical characteristics were obviously diverse in different parts of P. notoginseng, which is helpful for pharmacological evaluation and quality control of P. notoginseng.