Highlighting mass spectrometric fragmentation differences and similarities between hydroxycinnamoyl-quinic acids and hydroxycinnamoyl-isocitric acids

Abstract

BackgroundPlants contain a myriad of metabolites which exhibit diverse biological activities. However, in-depth analyses of these natural products with current analytical platforms remains an undisputed challenge due to the multidimensional chemo-diversity of these molecules, amplified by both isomerization and conjugation. In this study, we looked at molecules such as hydroxyl-cinnamic acids (HCAs), which are known to exist as positional and geometrical isomers conjugated to different organic acids namely quinic- and isocitric acid.ObjectiveThe study aimed at providing a more defined distinction between HCA conjugates from Amaranthus viridis and Moringa oleifera, using mass spectrometry (MS) approaches.MethodsHere, we used a UHPLC–MS/MS targeted approach to analyze isobaric HCA conjugates extracted from the aforementioned plants.ResultsMass spectrometry results showed similar precursor ions and fragmentation pattern; however, distinct differences were seen with ions at m/z 155 and m/z 111 which are associated with isocitric acid conjugates.ConclusionOur results highlight subtle differences between these two classes of compounds based on the MS fingerprints, enabling confidence differentiation of the compounds. Thus, these findings provide a template reference for accurate and confident annotation of such compounds in other plants.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-017-0262-8) contains supplementary material, which is available to authorized users.

Chemical profile of pineapple cv. Vitória in different maturation stages using electrospray ionization mass spectrometry

“…A hexoside loss is observed, yielding ions of m / z 197.8 (−134 Da) and m / z 225.6 (−105 Da), revealing a hexoside moiety in the molecule. Another compound detected in the pineapple Vitória is the coumaroy isocitrate, also previously described in the literature . The fragmentation profile of this ion (Fig.…”

“…S5b) indicates the loss of the coumaroyl group with subsequent dehydration of isocitric acid (m/z 173). 39 Feruloyl hexoside has been detected in wileyonlinelibrary.com/jsfa this cultivar, being also reported by Steingass. 17 Experiments of ESI(−) MS/MS (Fig.…”

“…Another compound detected in the pineapple Vitória is the coumaroy isocitrate, also previously described in the literature. 17,38,39 The fragmentation profile of this ion (Fig. S5b) indicates the loss of the coumaroyl group with subsequent dehydration of isocitric acid (m/z 173).…”

Corryocactus brevistylus (K. Schum. ex Vaupel) Britton & Rose (Cactaceae): Antioxidant, Gastroprotective Effects, and Metabolomic Profiling by Ultrahigh-Pressure Liquid Chromatography and Electrospray High Resolution Orbitrap Tandem Mass Spectrometry

“…Peak 9 was identified as caffeoyl-O-hexoside (C 15 H 17 O 9 − ), while two compounds (peak 12 and 13) had similar deprotonated molecules [M-H]-at m/z 353.0513. MS/MS fragmentation pattern of peak 12 (m/z 191.0191; 173.0085; 154.9978; 111.0078) indicated the presence of caffeoyl-(iso) citric acid while peak 13 was identified as its isomer (Masike et al, 2017 (Brito et al, 2014) or rhamnetin/isorhamnetin-O-neohesperidose (since isorhamnetin aglycone was found using standard). Peak 18 was identified as the flavanonol taxifolin (C 15 H 11 O 7 − ) (dihydroquercetin) that is a bioactive flavanonol commonly found in grapes (Yang et al, 2016).…”

“…Identification of compounds in Corryocactus brevistylus fruits by UHPLC-PDA-ESI-HRMS/MS Masike et al, 2017)…”