Chemical Transformation of Protopanaxadiol Type Ginsenoside Rb1, Rb2 and Rc Analyzed by RRLC-Q-TOF-MS

The developed rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (RRLC-Q-TOF-MS) method was applied for analyzing the chemical transformation of protopanaxadiol (PPD) type ginsenoside Rb-1, Rb-2 and R-c under acidic condition. And Rb-1, Rb-2, R-c and conversion products were analyzed in the ginseng processing. The experimental results demonstrated that chemical transformation mechanisms of protopanaxadiol type ginsenoside in acidic condition included saccharide hydrolysis, Delta 20( 21) - or Delta 20(22)-dehydration, and hydration addition reactions at C24 and C25. The RRLC-Q-TOF-MS/MS analysis included the specific product ions of aglycone PPD(m/z 459), Delta 20(21) - or Delta 20 (22)-dehydration-PPD (m/z 441), and C24, C25 hydrated-PPD (m/z 477). The tandem mass spectrometry(MS/MS) was discussed to provide a basis for structural characterization. The chemical transformation pathway 14 protopanaxadiol type ginsenoside was summarized. The established method was applied for analyzing PPD ginsenosides changes in raw white ginseng and processed red ginseng(100 and 120 degrees C) .