4B. The intensities
of ions b and f were relatively high in all ARG samples, but they were undetectable in the KRG samples. Ions a, c, d, and e were detected in most of the samples, but the intensities of these ions were find more relatively higher in all ARG samples than in the KRG group. The ion intensity trends suggested that components related to ions a–f could be used as potential chemical markers of ARG to distinguish it from KRG. The intensities of ions h and j were relatively high in all KRG samples, but they were undetectable in ARG. And ions g, i, k, and l were mainly detected in KRG as relatively higher intensities than in another group. These ion intensity trends suggested that components related to ions g–l could be used as potential chemical markers of KRG to distinguish it from ARG. In order to identify the important potential marker ions, such as ginsenoside Rf, Ra1, F2, and 24(R)-pseudoginsenoside F11, a qualitative analysis of ginsenosides present in KRG and ARG was performed. The identifications
of marker ions confirmed in samples by individual ginsenoside standard Caspase inhibitor materials were compared with respect to each other, and the results are summarized in Table 2. As a result, ions b and f were the fragment ions from the same molecule, and these ions were [M−H]– and [M−H+HCOOH]– from 24(R)-pseudoginsenoside F11, respectively, and ion h was [M−H]– from ginsenoside-Rf. These two ginsenosides occupy an important position in Fig. 4A (top-right and lower-left corner of “S”). This phenomenon confirmed the fact that ginsenoside-Rf and 24(R)-pseudoginsenoside F11 could be used as marker substances of KRG and ARG, respectively. Ginsenosides Ra1 and F2 were confirmed in all samples, but do not occupy an important position in Fig. 4A. This is because ginsenosides Ra1 and F2 had low values of “factor of change” derived from the low concentration and high standard deviation in samples. This means that these ginsenosides showed a low contribution to the
distinction between the processed ginseng genera. 4-Aminobutyrate aminotransferase Other potential marker ions were identified by comparing the spectrum of standard materials and selected ions in samples and individual retention times. Ions a and c were the fragment ions from the same molecule, and these ions were [M−H]– and [M−H+HCOOH]– from ginsenoside Rd, respectively. Ions d and e were the fragment ions from ginsenoside-Re with respect to [M−H]– and [M−H+HCOOH]–. Ions g and k were confirmed as [M−H]– and [M−H+HCOOH]– of ginsenoside Rc, and ion i was confirmed as [M−H]– ion of ginsenoside Rg1 by use of standard materials. These ions could not be used as a marker substance; it is only because of the difference between the concentrations of the two groups is a phenomenon. These are called “false-positives” in metabolomics and should be excluded by other verification methods (using standard material). Finally, in Fig. 4, ion j occupies an important position but could not be confirmed by standard materials.