High-performance liquid chromatography coupled with tandem mass spectrometry applied for metabolic study of ginsenoside Rb1 on rat

Liquid chromatography coupled with mass spectrometry and tandem mass spectrometry has been applied to investigate the in vivo metabolism of ginsenoside Rb1 in rat. Both positive electrospray ionization mass spectrometry and negative electrospray ionization mass spectrometry were used to identify the Rb1 and its metabolites in rat plasma, urine, and feces samples. Oxygenation and deglycosylation were found to be the major metabolic pathways of Rb1 in rat. A total of nine metabolites were detected in urine and feces samples collected after intravenous and oral administration. Deglycosylated metabolism of Rb1 generated other ginsenosides as the major metabolites, such as Rd, Rg3 or F2, Rh2, or C-K. This result indicates that the ginsenoside Rb1 has many pharmacological activities and could be used as a prodrug.