title: Identification of new trace triterpenoid saponins from the roots of Panax notoginseng by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.
abstract: Triterpenoid saponins are the major bioactive constituents of Panax notoginseng. In the study reported here, the fragmentation behavior of triterpenoid saponins from P. notoginseng was investigated by electrospray ionization tandem mass spectrometry (ESI-MS(n))and high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC/ESI-MS(n)). Analyses revealed that product ions from glycosidic and cross-ring cleavages can give a wealth of structural information regarding the nature of the aglycone, sugar types, the sequence and linkage information of sugar units. It is noted that different glycosylation positions remarkably influenced the fragmentation behaviors, which could assist in the differentiation of saponin analogues. To rationalize this characteristic, the collision energy required for various glycosidic cleavages was investigated. According to the summarized fragmentation rules, identification of triterpenoid saponins from the roots of P. notoginseng could be fulfilled, even when reference standards were unavailable. Furthermore, minor and trace constituents were enriched and detected by eliminating the major constituents in one of the saponin fractions. As a result, a total of 151 saponins, including 56 new trace ones, were identified or tentatively characterized from saponin fractions based on their retention times, HPLC/HRMS, HPLC/ESI-MS(n) fragmentation behaviors and comparison with literature data.
authors.affiliation: Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, China.
authors.forename: Yuanyan
authors.initials: Y
authors.lastname: Liu
authors.forename: Jianbei
authors.initials: J
authors.lastname: Li
authors.forename: Jiuming
authors.initials: J
authors.lastname: He
authors.forename: Zeper
authors.initials: Z
authors.lastname: Abliz
authors.forename: Jing
authors.initials: J
authors.lastname: Qu
authors.forename: Shishan
authors.initials: S
authors.lastname: Yu
authors.forename: Shuanggang
authors.initials: S
authors.lastname: Ma
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Dan
authors.initials: D
authors.lastname: Du
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D053723:Panax notoginseng / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D015203:Reproducibility of Results; D012503:Saponins / Q000032:analysis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014315:Triterpenes / Q000032:analysis / Q000737:chemistry*
chemical_list: D012503:Saponins; D014315:Triterpenes