Quality control and identification of steroid saponins from Dioscorea zingiberensis C. H. Wright by fingerprint with HPLC-ELSD and HPLC-ESI-Quadrupole/Time-of-fight tandem mass spectrometry

Abstract

In this study, a fingerprint of steroid saponins, the major bioactive constituents in the crude extracts from Dioscorea zingiberensis C. H. Wright (DZW), has been established for the first time by high-performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD) and the simultaneous characterization of the steroid saponins by high-performance liquid chromatography coupled with electrospray ionization-mass spectrometry and quadrupole tandem time-of-fight mass analyzers detection (HPLC-ESI-Q/TOF). These HPLC analyses were both carried out on a Welchrom C18 column (250 mm × 4.6 mm I.D., 5 μm) with a mobile phase composed of water and acetonitrile under gradient elution. There were 68 common characteristic peaks in the fingerprints, in which 12 of them were confirmed by comparing their mass spectra and retention times with those of the reference compounds. In order to identify the other unknown peaks, their fragmentation behaviors characteristic for the major groups of steroid saponins from DZW with six types of aglycone skeletons were discussed in detail, and possible MS/MS fragmentation pathways were proposed for aiding the structural identification of these components. According to the summarized fragmentation patterns, these peaks were tentatively assigned by matching their empirical molecular formula with those of the published compounds, or by elucidating their quasi-molecular ions and fragment ions referring to available literature information when the reference standards were unavailable. As a result, 22 steroid saponins were found in DZW for the first time. In addition, the quantitative analysis of the 12 known peaks was accomplished at the same time which indicated that there was a great variability in the amount of these active compounds in different batches in the crude extracts. This approach could demonstrate that the fingerprint could be considered to be a suitable tool to comprehensively improve the quality control of DZW, and the identification and structural elucidation of the peaks in the fingerprint may provide important experimental data for further pharmacological and clinical researches.

Applications of High Performance Liquid Chromatography in the Analysis of Herbal Products

“…Twelve saponins (purity >98%), 10 previously isolated and identified by the authors[86] and two purchased from a commercial supplier, were used as marker compounds. 2.…”

“…Twenty batches of samples of D. zingiberensis were obtained from different parts of China. A fully validated HPLC fingerprinting analysis[86] of each sample (10 mL) was performed on a Waters Alliance 2695 HPLC equipped with an online vacuum degasser, a high-pressure quaternary pump, an autosampler, and an Alltech 2000 evaporative light scattering detector (ELSD), utilizing a Welchrom C 18 column (250 Â 4.6 mm, 5 mm) with a binary gradient elution as follows: acetonitrile as solvent A and water as solvent B, initial 25% A, 0e5 min linear gradient 25e30% A, 5e20 min at 30% A, 20e35 min from 30 to 35% A, 35e45 min 35e47% A, 45e47 min 47e70% A, 47e60 min at 70% with a flow rate of 1 mL/min. Twelve saponins (purity >98%), 10 previously isolated and identified by the authors[86] and two purchased from a commercial supplier, were used as marker compounds.…”

Safety investigation on total steroid saponins extracts from Dioscorea zingiberensis C.H. Wright: Sub-acute and chronic toxicity studies on dogs

“…In recent years, D. zingiberensis , an ethno pharmacological and traditional TCM, has demonstrated to exert some newly emerging bioactivities as afore-mentioned in the “ introduction section ” and triggered our interest to explore its chemical composition for pharmacological and clinical applications in depth with extensive efforts [10–12]. The essential TSSN extracts originated from D. zingiberensis have been elaborated as the bioactive compounds that are attributable to the observable effects according to our previous chemical and pharmacological investigations which provided the concentration of some biomarker constituents [17, 21, 22]. Inspite of the increasing bioactivity data, the detailed available information regarding the potential toxicity in vivo of TSSN from this plant is relatively limited to an anterior report about cursory evaluation on mice and rats [16].…”

Therapeutic effects of total steroid saponin extracts from the rhizome of Dioscorea zingiberensis C.H.Wright in Freund's complete adjuvant induced arthritis in rats

“…The compounds in the TSSN has been analyzed by HPLC-ELSD and HPLC-ESI-MS in our laboratory [14]. The HPLC analysis was performed on a Waters Alliance 2695 equipment (Waters, Milford, MA, USA) including Alltech 2000ES (Alltech, USA), and the mass spectrometer equipped with a Q-TOF Premier, a quadrupole and orthogonal acceleration time-of-flight tandem mass spectrometer with an electrospray ionization interface.…”