RRLC-Q-TOF-MS研究人参二醇型皂苷Rb1,Rb2和Rc的化学转化

Chemical Transformation of Protopanaxadiol Type Ginsenoside Rb_1,Rb_2 and Rc Analyzed by RRLC-Q-TOF-MS

将高分离快速液相色谱-四极杆-飞行时间质谱(RRLC-Q-TOF-MS)联用技术用于人参二醇型(PPD)皂苷Rb_1,Rb_2和Rc在酸性条件下的化学转化研究,并对人参炮制过程中人参二醇型皂苷Rb_1,Rb_2和Rc及其转化产物的相对含量进行了分析.利用RRLC-Q-TOF-MS联用和串联质谱(MS/MS)技术对化合物的保留时间、精确分子量及串联质谱碎片信息进行分析,以鉴定化合物的结构.研究结果表明,人参二醇型皂苷在酸性条件下的化学转化包括:取代糖基的水解反应、Δ20(21)或Δ20(22)位的脱水反应和C24,C25位的水合加成反应.在MS/MS分析中,质谱峰m/z 459,477和441分别为人参二醇苷元、C24,C25位水合人参二醇苷元和Δ20(21)或Δ20(22)位脱水人参二醇型苷元的特征离子,这为人参二醇型皂苷及其转化产物的结构鉴定提供了依据,并以此总结了人参二醇型皂苷的化学转化途径.还利用所建立的方法研究了生晒参和红参(100和120℃)中PPD人参皂苷在炮制过程中的变化.

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 Rb1,Rb2 and Rc under acidic condition. And Rb1,Rb2,Rc 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,Δ20（ 21）-or Δ20（ 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）,Δ20（ 21）-or Δ20（ 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 for 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 ℃）.