Development and validation of an UFLC–MS/MS assay for the absolute quantitation of nine notoginsenosides in rat plasma: Application to the pharmacokinetic study of Panax Notoginseng Extract

• Built a robust method for the measurement of multi-notoginsenoside.
• A new LC–MS/MS system, Shimadzu UFLC–MS/MS-8050, was used.
• Pharmacokinetics of notoginsenosides in rats was evaluated.
• The method would be useful for the PK studies for other saponins.

Notoginsenosides, the main active gradients of Chinese traditional medicine Panax notoginseng, possesses a variety of biological activities including antioxidant property, anti-hyperglycemic, anti-obese, etc. However, pharmacokinetic evaluation for notoginsenosides is still a formidable task due to their low concentrations and complex components in vivo. The summation of this work generated a rapid and sensitive method for quantitative analysis of multi-notoginsenoside in rat plasma based on ultra fast liquid chromatographic-tandem mass spectrometric. After liquid–liquid extraction by n-butanol, notoginsenoside R1, Rg3, Rd, Rg2, Rb2, Rf, Rg1, Rb1 and Re were simultaneously monitored in negative ionization mode after separating on a Thermo ODS C18 column (5 mm 50 mm × 2.1 mm) by a binary gradient elution, and all compounds were analyzed within 9 min. Multiple reaction monitoring (MRM) was performed as follows: R1 (m/z 967.7 → 637.4), Rg3 (m/z 819.6 → 621.4), Rd (m/z 981.6 → 783.5), Rg2 (m/z 819.6 → 475.4), Rb2 (m/z 1113.4 → 783.4), Rf (m/z 835.6 → 475.4), Rg1 (m/z 835.6 → 637.6), Rb1 (m/z 1143.7 → 945.6), Re (m/z 981.6 → 637.4), internal standard (digoxin, m/z 815.5 → 779.4). Validation parameters (linearity, sensitivity, intra-and inter-assay precision and accuracy, recovery and matrix effect) were within acceptable ranges and biological extracts were stable during the entire storing and preparing process. This UFLC–MS/MS approach was further validated by being applied to the pharmacokinetic study for P. Notoginseng extract in rats, and the pharmacokinetic parameters were calculated by Winolin software. Thus, the presently developed methodology was simple, robust, accurate, precise, and would be useful for the pharmacokinetic studies for all kinds of notoginsenosides and other herbal saponins.