title: Characterization of C-glycosyl quinochalcones in Carthamus tinctorius L. by ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.
abstract: C-Glycosyl quinochalcones are unique components in Carthamus tinctorius L. The reported C-glycosyl quinochalcones have the same quinochalcone skeleton with a hydroxyl group at the 5'-position and a glucose linked to this position with a carbon-carbon bond. In this study, the standard hydroxysafflor yellow A and water-extracted fraction of Carthamus tinctorius L. were analyzed by ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOFMS) in both positive and negative ion modes. The fragmentation pathways of C-glycosyl quinochalcones were interpreted and validated by accurate mass measurement. Their fragmentation showed a special cleavage at the C-C bond except for the typical internal cleavage at the sugar moiety of other C-glycosyl flavonoids. In positive ion mode, cleavage of the 5'-glucose produced an [M+H-162](+) ion by a neutral loss, while cleavage of the 5'-glucose in negative ion mode led to an [M-H-163](-.) ion by radical cleavage. The cleavage from the carbonyl group produced fragment ions containing an A or a B ring. The fragment ions containing an A ring were common product ions of seven compounds in both ion modes, and fragment ions containing the B ring were used to judge the different substituent groups at the 3'-position. The fragmentation patterns of seven structurally related C-glycosyl quinochalcones were analyzed systematically and the formation of the fragment ions in two modes is explained in detail in this report. UPLC/Q-TOFMS is an effective tool for characterizing a complex sample, which gives higher resolution separation and generates accurate mass measurement of the product ions.
authors.affiliation: Dalian Institute of Chemical Physics, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Dalian, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Jin
authors.forename: Xiu-li
authors.initials: XL
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.forename: Yuan-sheng
authors.initials: YS
authors.lastname: Xiao
authors.forename: Yan-xiong
authors.initials: YX
authors.lastname: Ke
authors.forename: Xing-ya
authors.initials: XY
authors.lastname: Xue
authors.forename: Fei-fang
authors.initials: FF
authors.lastname: Zhang
authors.forename: Xin-miao
authors.initials: XM
authors.lastname: Liang
mesh_terms: D031187:Carthamus tinctorius / Q000737:chemistry*; D002599:Chalcone / Q000031:analogs & derivatives* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry*; D010860:Pigments, Biological / Q000737:chemistry; D010936:Plant Extracts; D010946:Plants, Medicinal / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D003373:Coumaric Acids; D005960:Glucosides; D006027:Glycosides; D010860:Pigments, Biological; D010936:Plant Extracts; D011809:Quinones; C503191:safflomin A; C085278:hydroxysafflor yellow A; D002599:Chalcone; C103141:carthamine