利用ESI-Q-TOF-MS/MS区分人参皂苷Rh2和CK

Differentiation of Ginsenoside Isomers Rh_2 and CK Using ESI-Q-TOF-MS/MS

为了建立快速、准确地区分人参皂苷同分异构体Rh2和CK的分析方法,利用电喷雾-四极杆-飞行时间串联质谱(ESI-Q-TOF-MS/MS)技术,分别在正离子、负离子模式下采用不同的碰撞能量对人参皂苷同分异构体Rh2和CK进行MS/MS研究。结果表明:在负离子模式下,二者均产生相同的特征碎片离子;但在相同的碰撞能量下,Rh2的特征碎裂离子丰度明显低于CK的碎裂离子丰度。在正离子模式下,二者的裂解规律有明显的差异;CK在碰撞能量为20、40、60eV时,出现特征碎片离子m/z465和m/z203;而Rh2则仅在较高碰撞能量60eV时,产生该特征碎片离子。通过比较Rh2和CK的MS/MS裂解规律,能够快速区分这两个同分异构体。

A rapid analysis method of electrospray-quadrupole-time-of-flight mass spectrometry （ESI-Q-TOF-MS/MS） was established to differentiate ginsenoside isomers Rh2 and compound K （CK）.Based on the analysis of MS/MS product ions with different collision energy in both negative and positive ion mode,ginsenoside isomers Rh2 and CK are distinguished.The results show that the fragmentation pathway of Rh2 and CK in negative ion mode is similar.The difference is that the fragment ion abundance of Rh2 is significantly lower than that of CK with the same collision energy.The fragmentation behavior of Rh2 is different from CK in positive ion mode,specific fragment ions m/z 465 and m/z 203 are produced with collision energy 20,40 and 60 eV in CK,but Rh2 produces the similar specific fragment ions only with collision energy 60 eV in MS/MS.The MS/MS fragmentation pathway is particularly useful in the identification of ginsenoside isomers Rh2 and CK.