A new liquid chromatography-high resolution Orbitrap mass spectrometry-based strategy to characterize Glucuronide Oleanane-type Triterpenoid Carboxylic Acid 3, 28-O-Bidesmosides (GOTCAB) saponins.A case study of Gypsophila glomerata Pall ex M. B. (Caryophyllaceae)

In this study, the fragmentation behaviors of GOTCAB from methanol-aqueous root extract of Gypsophila glomerata Pall ex M. B. (Caryophyllaceae) were investigated using ultra-high performance liquid chromatography (UHPLC) coupled with hybrid quadrupole-Orbitrap high resolution mass spectrometry (HRMS). A new saponin was isolated and its structure was established by 1D and 2D-NMR spectroscopic experiments as 3-O-β-D-galactopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucuronopyranosyl gypsogenin 28-O-α-L-arabinopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester. On the basis of the accurate mass measurements, fragmentation patterns in MS/MS analyses and comparison with previously isolated authentic references, a total of 41 GOTCAB saponins were identified or tentatively elucidated in G. glomerata roots, including 14 pairs of isobars. Possible fragmentation pathways for three groups of GOTCAB are suggested. The group I appeared to be GOTCAB of gypsogenin with two carbohydrate chains: a branched trisaccharide at C-3 and tri- to hexa-saccharide attached to C-28 of the aglycone through a deoxyhexose residue. Saponins with monoacetylated (group II) or sulphated (group III) C-28 chain were evidenced, as well as quillaic and oleanolic acid GOTCAB. Sixteen GOTCAB were previously not described. The content of Gypsophila prosaponins, gypsogenin 3-O-glucuronide (7.4079 ± 0.0723 mg/g dry weight, dw) and quillaic acid 3-O...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research