The comprehensive 1H-NMR and 13C-NMR spectral data of compounds 1–21 are worth determining for the structures of the less polar ginsenosides as some of their 1H-NMR and 13C-NMR spectroscopic

data are not available. Other data are either scattered throughout published papers, or dated, therefore it is hard to compare the structures of the isolated compounds. PF-01367338 mw In the study, the results were assigned using one-dimensional and two-dimensional NMR spectroscopic methods and were also confirmed by comparison with previously published data. Some signals, such as those for the methyl groups of C-26–C-30 and the saturated methylenes, which have not been reported previously, were unambiguously determined using two-dimensional NMR spectra including 1H-1H COSY, HSQC and HMBC spectra. The 13C-NMR spectral data suggested the

following information for the structural elucidation of the ginsenosides isomers. First, the chemical BGB324 shifts of the characteristic peaks between the 20(S) and 20(R) ginsenosides provided information for the identification of the stereoisomers. In particular, changes in the chemical shifts between the S- and R- forms at C-17, C-21 and C-22 in the 13C-NMR spectra were approximately Δδ (δS – δR) +4.1 ± 0.1, +4.3 ± 0.1, and −7.4 ± 0.1 ppm, respectively ( Table 2 and Table 4). Next, the presence of the signal (δC 88.8 ± 0.1 ppm) of the hydroxyl carbon at C-3, which did not overlap with other hydroxyl groups in the backbone and the sugar moieties, easily indicated whether it was a PPD- (1–8, 17, and 20) or PPT-type (9–16 and 18). In addition, the signals at δC 170.6 ± 0.1 showed the existence

of the acetyl groups (5, 6, 15, and 16) ( Table 2 and Table 4). It was assumed that they were produced from the malonyl moiety by decarboxylation during the manufacturing process and were located at C-6 in the glucose group (5, 6, 15, and 16) [23]. Finally, the chemical shifts of the down-field signals indicated the type of backbones. The values for a double bond at Δ24(25) in 3,12,20-trihydroxydammar-24-ene and 3,6,12,20-tetrahydroxydammar-24-ene (1–6, 9–12, 15, and 16) were δC 126.1 ± 0.2 (C-24) and 130.1 ± 0.1 (C-25), respectively ( Table 2 and Table 4). However, they were shifted to δC 124.2 ± 1.0 and 131.2 ± 0.0 as a result Liothyronine Sodium of the dehydration at Δ20(21) (17) or Δ20(22) (18 and 20) ( Table 6). The differences between the chemical shifts of δC 155.5 and 108.1, and of δC 140.1 ± 0.1 and 123.4 ± 0.2 ppm indicated the discrimination of 3,12-dihydroxydammar-20, 24-diene (17) and 3,12-dihydroxydammar-20(22),24-diene (18 and 20). These results were in perfect agreement with previously published values [21], [24] and [25]. Compound 21, an oleanane-type triterpene, might be produced by the selective hydrolysis of sugar residues at C-3 in ginsenoside Ro [26] ( Table 6). All the contributing authors declare no conflicts of interest.