仿刺参皂苷类化合物的电喷雾负离子质谱裂解规律研究

Study on the Fragmentation Pathways of Triterpene Glycosides from Apostichopus japonicus Selenka by Negative Electrospray Ionization Mass Spectrometry

采用电喷雾-四极杆-飞行时间质谱(ESI-Q-TOF MS)在负离子检测方式下,对仿刺参中4种皂苷类成分的裂解途径进行研究。通过ESI-MS产生的[M-H]-获得相应化合物的相对分子质量信息,对[M-H]-进行碰撞诱导解离(CID)获得相应化合物的裂解途径信息。研究发现,4种皂苷化合物的ESI-MS/MS裂解规律相同,首先断裂苷元上的18(20)内酯键,然后连续丢失糖链的末端单糖,最后生成苷元的特征碎片离子m/z423,这些特征有助于皂苷类化合物的结构解析。

The fragmentation pathways of four triterpene glycosides from Apostichopus japonicus Selenka were investigated in negative ion mode by ESI-Q-TOF MS.The -ions were observed by ESI-MS,from which the molecular weights were obtained.The collision induced dissociation（CID） data of the -ions provide fragmentation pathways of the triterpene glycosides.Results show that four compounds have the same fragmentation pathway.The cleavage is initiated by a loss of 18（20）-lactone residue from the aglycon,then consecutively loses monosaccharide residue of sugar chain,and finally yields a signature ion peak at m/z 423.These characteristic fragmentations will be helpful in identifying the structures of triterpene glycosides.