Analysis of catalpol derivatives by characteristic neutral losses using liquid chromatography combined with electrospray ionization multistage and time‐of‐flight mass spectrometry

Abstract

2684 Letter to the Editor Scheme 2. Proposed fragmentation pathways of iridoids in V. linariifolia: (a) catalpol; (b) geniposidic acid; (c) scandoside; and (d) aucubin.

HPLC‐DAD‐ESI‐Q‐TOF‐MS/MS profiling of Verbascum ovalifolium Donn ex Sims and evaluation of its antioxidant and cytogenotoxic activities

“…Another seven iridoid glycosides were identified in V. ovalifolium extracts. Showing characteristic fragmentation patterns (Table S1) similar with those reported in the literature, peaks 2 , 4 , 6 and 7 , with pseudomolecular ions at m/z 361, 345, 363 and 347, respectively, were tentatively identified as catalpol, aucubin, harpagide and ajugol, respectively. Moreover, comparison with an authentic standard led to the unequivocal identification of peak 4 as aucubin.…”

“…The most frequent fragment ions observed in the MS/MS spectra of acylated catalpol‐type iridoid diglycosides resulted from the loss of the glucosyl (162 Da) moiety, followed by the invariable loss of the neutral C 5 H 6 O 3 fragment (114 Da). As suggested by Hong et al, this fragmentation pattern is characteristic of catalpol derivatives and can be explained by the fact that the hemiacetal group from the six atom ring firstly suffers an internal rearrangement to a dialdehydic structure, followed by the cleavage of the remaining five carbon atom cycle. The further fragment ion observed was generated from the deglucosylated ion by the loss of caltapolgenin residue C 9 H 10 O 4 (182 Da).…”

“…Total phenolic, flavonoid, aucubin, chlorogenic acid, verbascoside, luteolin-7-O-glucoside and luteolin contents of Verbascum ovalifolium extracts -type iridoid diglycosides resulted from the loss of the glucosyl (162 Da) moiety, followed by the invariable loss of the neutral C 5 H 6 O 3 fragment (114 Da). As suggested by Hong et al,23 this fragmentation pattern is characteristic of catalpol derivatives and can be explained by the fact that the hemiacetal group from the six atom ring…”

Tentative Characterisation of Iridoids, Phenylethanoid Glycosides and Flavonoid Derivatives from Globularia alypum L. (Globulariaceae) Leaves by LC‐ESI‐QTOF‐MS

“…Furthermore, specioside (peak 34 ) was tentatively characterised by comparing its MS data with those reported in the literature (Hong et al ., ). The MS/MS analysis of this compound (Fig.…”

Screening of glycoside isomers in P. scrophulariiflora using ionic liquid‐based ultrasonic‐assisted extraction and ultra‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry

“…Cleavage of the ester bond provided a vanilloxyl ion at m/z 167.0343 (C 8 H 7 O 4 , 167.0344, –0.60 ppm). The hemiacetal group in the precursor ion at m/z 349.0921 facilitated isomerization of the two aldehyde groups, and the product ion appeared at m/z 235.0608 (C 12 H 11 O 5 , 235.0606, 0.85 ppm), formed by the ring‐opening reaction with the neutral loss of C 5 H 6 O 3 . Successive loss of a molecule of carbon monoxide produced a fragment ion at m/z 207.0659 (C 11 H 11 O 4 , 207.0657, –0.97 ppm).…”