Differentiation and identification of ginsenoside structural isomers by two-dimensional mass spectrometry combined with statistical analysis

Abstract

Background In the current phytochemical research on ginseng, the differentiation and structural identification of ginsenosides isomers remain challenging. In this paper, a two-dimensional mass spectrometry (2D-MS) method was developed and combined with statistical analysis for the direct differentiation, identification, and relative quantification of protopanaxadiol (PPD)-type ginsenoside isomers. Methods Collision-induced dissociation was performed at successive collision energy values to produce distinct profiles of the intensity fraction (IF) and ratio of intensity (RI) of the fragment ions. To amplify the differences in tandem mass spectra between isomers, IF and RI were plotted against collision energy. The resulting data distributions were then used to obtain the parameters of the fitted curves, which were used to evaluate the statistical significance of the differences between these distributions via the unpaired t test. Results A triplet and two pairs of PPD-type ginsenoside isomers were differentiated and identified by their distinct IF and RI distributions. In addition, the fragmentation preference of PPD-type ginsenosides was determined on the basis of the activation energy. The developed 2D-MS method was also extended to quantitatively determine the molar composition of ginsenoside isomers in mixtures of biotransformation products. Conclusion In comparison with conventional mass spectrometry methods, 2D-MS provides more direct insights into the subtle structural differences between isomers and can be used as an alternative approach for the differentiation of isomeric ginsenosides and natural products.

Ginsenoside M1 Induces Apoptosis and Inhibits the Migration of Human Oral Cancer Cells

“…Ginsenoside M1 and ginsenoside Rh2 are the major ginsenoside metabolites with anticancer activities [ 25 ]. In addition, ginsenoside M1 and ginsenoside Rh2 are positional isomers [ 26 ], therefore, we investigated the effect of ginsenoside M1 and ginsenoside Rh2 in human oral cancer cells. Human oral cancer cells SAS and OEC-M1 were plated at 5 × 10 5 cells per 6-cm dish in 2 mL of culture medium and were grown overnight at 37 °C in a 5% CO 2 incubator.…”

“…Furthermore, ginsenoside M1 and ginsenoside Rh2 showed different killing effect in normal gingival epithelioid SG cells. As ginsenoside M1 and ginsenoside Rh2 are positional isomers [ 26 ], we suggested that the different killing effect of ginsenoside M1 and ginsenoside Rh2 on normal gingival epithelioid SG cells may be structurally selective. Although ginsenoside M1 was less toxic to human gingival epithelioid SG cells than ginsenoside Rh2, ginsenoside M1 showed a similar killing effect in OEC-M1 cells and SG cells.…”

Anticancer Activities of Ginsenosides, the Main Active Components of Ginseng

“…Some ginsenosides, such as Rg2, Rg3, Rh1, and Rh2, exist in different stereoisomeric forms, 20-(S) and 20-(R), depending on the position of the hydroxyl group in C-20. Other ginsenosides, including Rb2, Rb3, Rc, aglycone, Rg1, and F11, contain different saccharide substituents [ 41 , 42 ]. However, not all ginsenosides occur naturally in ginseng.…”

A rapid, simultaneous and quantitative analysis of 26 ginsenosides in white and red Panax ginseng using LC–MS/MS

“…It is very important to quantitate the constitutional and stereisomeric isomer of ginsenosides independently because each isomer was known to have different activity [10][11][12]. Analysis of ginsenoside isomers required the derivatization for GC analysis [13] or 2-dimensional UHPLC-MS/MS for the separation [14]. Separating isomers using MS detection is challenging due to the similarity of the MS spectra and MRM transition between isomers.…”