title: Triterpenoid saponins profiling by adducts-targeted neutral loss triggered enhanced resolution and product ion scanning using triple quadrupole linear ion trap mass spectrometry.
abstract: Triterpenoid saponins (TSs) are a unique class of high molecular weight glycosides and have been frequently used in cosmetic and phytotherapy industry. There is a great need to comprehensively profile these plant metabolites for studying their functions. In the present study, a novel adducts targeted neutral loss (NL), triggered enhanced resolution (ER) and enhanced product ion (EPI) scanning approach were described for TSs profiling using a triple quadrupole linear ion trap mass spectrometry. This approach circumvented the disadvantages of poor glycosidic bond cleavage of TSs by monitoring the NH3 (NL17) and HCOOH (NL46) loss of their abundant ammonium and formate adducts, respectively. The sugar-loss independent NL scanning served as a sensitive survey scan and triggered information-dependent ER and EPI scans to increase peak assignment confidence. NL17 was superior to NL46 for TSs characterization due to the better fragmentation of ammonium adducts than formate adducts. For those TSs undetectable by NL17, precursor ion (PI) scan for sapogenin fragments could be used to screen out non-adducted TSs. The NL/PI-ER-EPI approach was applied for TSs profiling in Astragali Radix, a famous medicinal and nutritional plant widely used in Asian countries and United States. In total, 136 TSs were detected while previous research using high resolution mass spectrometry based full scan only detected 22 TSs in this herb.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao, China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Yan
authors.affiliation: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative Region.
authors.forename: Ge
authors.initials: G
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-tech Park, Shanghai 201203, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao, China.
authors.forename: Yitao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao, China. Electronic address: ruyan@umac.mo.
authors.forename: Ru
authors.initials: R
authors.lastname: Yan
mesh_terms: D013058:Mass Spectrometry; D012503:Saponins / Q000032:analysis* / Q000737:chemistry*
chemical_list: D012503:Saponins
keywords: Adducts targeted neutral loss scanning; Triple quadrupole linear ion trap mass spectrometry; Triterpenoid saponins profiling