Characterization of ginsenoside structural isomers from mixtures using in situ methylation with direct analysis in real-time ionization tandem mass spectrometry

Recent application of direct analysis in real time mass spectrometry in plant materials analysis with emphasis on traditional Chinese herbal medicine

“…It was reported that after methylated by TMAH, the ginsenoside isomers, even those with minor structure differences, exhibited distinct signals in DART‐MS spectra and tandem MS spectra, which was successfully applied to differentiate ginsenoside isomers, including F1/Rh1, R2/F3, Rg2/Rg3, Rd/Re, and Rf/Rg1/F11 (Ren et al, 2022). For example, the full methylation products of intact ginsenoside at m / z 956.70 were observed in Figure 7A,B for R 2 and F 3 .…”

“…Unlabeled black, pink, and red arrows indicate mass differences of 18 (H 2 O), 14 (CH 2 ), and 32 (H 2 O+CH 2 ) between peaks, respectively. Reproduced from Ren et al (2022) with permission from American Chemical Society. [Color figure can be viewed at wileyonlinelibrary.com]…”