Structural Characterization of Flavonoid Glycoconjugates and Their Derivatives with Mass Spectrometric Techniques

Abstract

Abstract:Mass spectrometry is currently one of the most versatile and sensitive instrumental methods applied to structural characterization of plant secondary metabolite mixtures isolated from biological material including flavonoid glycoconjugates. Resolution of the applied mass spectrometers plays an important role in structural studies of mixtures of the target compounds isolated from biological material. High-resolution analyzers allow obtaining information about elemental composition of the analyzed compounds. Application of various mass spectrometric techniques, including different systems of ionization, analysis of both positive and negative ions of flavonoids, fragmentation of the protonated/deprotonated molecules and in some cases addition of metal ions to the studied compounds before ionization and fragmentation, may improve structural characterization of natural products. In our review we present different strategies allowing structural characterization of positional isomers and isobaric compounds existing in class of flavonoid glycoconjugates and their derivatives, which are synthetized in plants and are important components of the human food and drugs as well as animal feed.

Metabolite Profiling of Aquilaria malaccensis Leaf Extract Using Liquid Chromatography-Q-TOF-Mass Spectrometry and Investigation of Its Potential Antilipoxygenase Activity In-Vitro

“…LC/Q-TOF-MS represents an important approach to identifying unknown constituents in plant extracts. The chemical constituents of A. malaccensis leaves extracted with 95% ethanol were analyzed via LC/Q-TOF-MS in both positive and negative ionization modes, since flavonoid fragmentations can be recorded on positive and negative ion modes [33]. However, the negative ion mode in the current study provided a wider range of metabolites than the positive ion mode.…”

“…Apigenin was isolated earlier from A. sinensis flowers [59]. However, the identification of peak C21 (m/z 431.0995, C 21 H 19 O 10 − ) relied on the formation of ion fragments at m/z 311 caused by the loss of 90 Da, which corresponds to the cross-ring cleavage of the sugar unit [33] and suggesting an aglycone-C-hexoside. The occurrence of another fragment ion at m/z 269 (apigenin aglycone) is caused by the loss of hexose moiety (-162 Da).…”

Valorisation of the green waste parts from turnip, radish and wild cardoon: Nutritional value, phenolic profile and bioactivity evaluation

“…Peak 18 BR was positively identified as kaempferol-3-O-glycoside by comparison of its UV spectrum (λ máx 340 nm) and retention time with the commercial standard. Peaks 8 RS , 9 RS , 6 RS , 7 RS , 8 BR , 10 RS , and 11 RS were tentatively identified as kaempferol linked to different sugar moieties, rhamnoside-pentoside ( Barros, Dueñas, Ferreira, Carvalho, & Santos-Buelga, 2011;Kachlicki, Piasecka, Stobiecki, & Marczak, 2016). Peaks 17 BR , 12 BR , 15 BR , 12 RS , 13 RS , 9 BR , 4 BR , 6 BR , 7 BR were tentatively identified as kaempferol linked to sugar moieties and phenolic acids (ferulic, malonic, sinapic, and p-coumaric acids).…”

Chemical and absorption signatures of Xiao Chai Hu Tang

“…Six flavanone O ‐glucuronides (29, 32, 33, 35, 37, 38, 40) were detected from XCHT. The C ‐glycosides, compounds 7 (apigenin 6,8‐di‐glucoside), 8 (schaftoside), 13 (violanthin), 15 (chrysin‐6‐C‐β‐D‐glucopyranoside‐8‐C‐α‐L‐arabinopyranoside), 16 (chrysin 6‐C‐α‐L‐arabinopyranoside‐8‐C‐glucoside), 18 (isomer of violanthin), 20 (isomer of chrysin‐6‐C‐β‐D‐8‐C‐α‐L‐arabinopyranoside), 22 (chrysin 8‐C‐glucopyranoside), and 28 were identified using the fragments of m/z 120 and 90 for C‐hexose, m/z 104 and 74 for C‐deoxyhexose, and m/z 90 and 60 for C‐pentose . For di‐C‐glucoses, the compounds were identified by fragmention into [M − 120 − H] − and [M − 240 − H] − .…”