Table 2. 1H and 13C NMR data for metabolites M1–M4 in MeOD (δ in ppm).
| No. | M1 | M2 | M3 | M4 | ||||
|---|---|---|---|---|---|---|---|---|
| δC | δH | δC | δH | δC | δH | δC | δH | |
| 2 | 163.2 | 163.5 | 162.9 | 163.3 | ||||
| 3 | 114.2 | 6.28 (1H, d, J = 9.5 Hz) | 114.5 | 6.29 (1H, d, J = 9.5 Hz) | 115.4 | 6.35 (1H, d, J = 9.5 Hz) | 115.6 | 6.35 (1H, d, J = 9.5 Hz) |
| 4 | 145.6 | 7.90 (1H, d, J = 9.5 Hz) | 145.6 | 7.89 (1H, d, J = 9.5 Hz) | 145.4 | 7.93 (1H, d, J = 9.5 Hz) | 145.5 | 7.92 (1H, d, J = 9.5 Hz) |
| 4a | 115.3 | 114.6 | 116.9 | 116.6 | ||||
| 5 | 130.4 | 7.56 (1H, d, J = 8.6 Hz) | 110.6 | 7.20 (1H, s) | 130.0 | 7.60 (1H, d, J = 8.5 Hz) | 111.1 | 7.23 (1H, s) |
| 6 | 115.2 | 7.12 (1H, dd, J = 8.6, 2.3 Hz) | 148.3 | 118.9 | 7.26 (1H, dd, J = 8.5, 2.2 Hz) | 150.2 | ||
| 7 | 162.3 | 151.8 | 157.3 | 146.8 | ||||
| 8 | 105.3 | 7.09 (1H, d, J = 2.3 Hz) | 105.5 | 7.22 (1H, s) | 109.6 | 7.33 (1H, d, J = 2.2 Hz) | 110.8 | 7.55 (1H, s) |
| 8a | 156.7 | 150.7 | 156.1 | 149.7 | ||||
| 1′ | 101.9 | 5.06 (1H, d, J = 7.5 Hz) | 101.9 | 5.10 (1H, d, J = 7.5 Hz) | ||||
| 2′ | 74.6 | 3.54 (1H, m) | 74.5 | 3.58 (1H, m) | ||||
| 3′ | 73.5 | 3.54 (1H, m) | 73.5 | 3.55 (1H, m) | ||||
| 4′ | 77.6 | 3.54 (1H, m) | 77.6 | 3.54 (1H, m) | ||||
| 5′ | 76.5 | 3.83 (1H, m) | 76.5 | 3.84 (1H, dd, J = 7.5, 2.1 Hz) | ||||
| 6′ | 176.2 | 176.2 | ||||||
| OMe | 57.0 | 3.91 (3H, s) | 57.0 | 3.89 (3H, s) | ||||
NMR spectroscopy was performed on a Bruker Ascend 600 NMR spectrometer equipped with cryogenic probe (600 MHz for 1H NMR and 150 MHz for 13C NMR) using standard Bruker pulse programs. About 1 mg of each sample was dissolved in 0.5 ml MeOD with TMS as the internal standard (0.05% V/V), and the operation temperature was 298.0 K.