Table 1.
1H- and 13C-nuclear magnetic resonance (NMR) spectral data of four phenolic compounds isolated from red pine twigs
| Position | PMG | TRR | LRR | DHM |
|---|---|---|---|---|
| 1H-NMR | ||||
| H-2 | 6.99 (1H, d, J=2.0 Hz) | 7.02 (1H, d, J=2.0 Hz) | 7.00 (1H, d, J=2.0 Hz) | 4.84 (1H, d, J=11.5 Hz) |
| H-3 | 4.47 (1H, d, J=11.5 Hz) | |||
| H-4 | 6.98 (1H, t, J=2.0 Hz) | |||
| H-5 | 6.49 (1H, d, J=2.0 Hz) | 6.73 (1H, brs) | ||
| H-6 | 6.99 (1H, d, J=2.0 Hz) | 6.88 (1H, d, J=2.0 Hz) | 6.86 (1H, d, J=2.0 Hz) | 5.88 (1H, d, J=2.0 Hz) |
| H-7 | 2.45 (1H, t, J=7.8 Hz) | 2.52 (1H, m) | ||
| H-8 | 1.64 (1H, m) | 1.69 (1H, m) | 5.91 (1H, d, J=2.0 Hz) | |
| H-9 | 3.40 (1H, m) | 3.42 (1H, m) | ||
| H-2’ | 7.38 (1H, d, J=8.5 Hz) | 7.05 (H, d, J=2.0 Hz) | 7.05 (1H, d, J=8.5 Hz) | 6.54 (1H, s) |
| H-3’ | 7.05 (1H, d, J=8.5 Hz) | |||
| H-4’ | 7.09 (1H, d, J=1.5 Hz) | |||
| H-5’ | 7.05 (1H, d, J=8.5 Hz) | 6.53 (1H, s) | 6.73 (1H, brs) | |
| H-6’ | 7.38 (1H, d, J=8.5 Hz) | 6.90 (1H, d, J=2.0 Hz) | 6.87 (1H, d, J=2.0 Hz) | 6.54 (1H, s) |
| H-7’ | 5.45 (1H, d, J=6.5 Hz) | 5.48 (1H, d, J=6.5 Hz) | ||
| H-8’ | 2.50 (1H, m)→3.96 m | 2.50 (1H, brs)→3.46 m | ||
| H-9’ | 3.70 (1H, m), 3.65 (1H, m) | 3.72 (1H, m), 3.64 (1H, m) | ||
| H-α | 6.31 (1H, d, J=16.0 Hz) | |||
| H-β | 7.28 (1H, d, J=16.0 Hz) | |||
| Hexose | Glucose | Rhamnose | Rhamnose | |
| H-1 | 4.84 (1H, d, J=7.5 Hz) | 5.24 (1H, d, J=1.5 Hz) | 5.24 (1H, d, J=1.5 Hz) | |
| H-2∼H5 | 3.20∼3.67 | 3.17∼3.84 | 3.17∼3.84 | |
| H6 | 3.79 | 1.10 (3H, d, J=6.5 Hz) | 1.06 (3H, d, J=6.5 Hz) | |
| OCH3 | 3.81 (3H, s) | 3.76 (3H, s) | 3.76 (3H, s) | |
| OCH3 | 3.77 (3H, s) | |||
| 13C-NMR | ||||
| 1 | 141.55 | 134.92 | 135.19 | |
| 2 | 101.21 | 110.59 | 110.55 | 85.32 |
| 3 | 151.09 | 149.99 | 150.03 | 73.75 |
| 4 | 105.32 | 144.58 | 144.78 | 198.33 |
| 5 | 149.13 | 115.76 | 116.45 | 165.35 |
| 6 | 109.21 | 117.82 | 117.84 | 97.43 |
| 7 | 31.27 | 31.29 | 168.82 | |
| 8 | 34.66 | 34.69 | 96.40 | |
| 9 | 63.24 | 60.18 | 164.50 | |
| 10 | 101.87 | |||
| 1’ | 132.28 | 128.71 | 128.74 | 129.19 |
| 2’ | 112.27 | 118.04 | 117.96 | 108.16 |
| 3’ | 122.60 | 140.68 | 143.35 | 146.93 |
| 4’ | 117.91 | 144.70 | 145.46 | 134.98 |
| 5’ | 122.60 | 114.85 | 112.50 | 146.93 |
| 6’ | 112.27 | 117.82 | 117.84 | 108.16 |
| 7’ | 86.11 | 86.48 | ||
| 8’ | 53.69→56.06 | 53.43→55.70 | ||
| 9’ | 60.18 | 63.13 | ||
| Cα | 128.10 | |||
| Cβ | 129.75 | |||
| Hex-1 | Glu-1 (102.61) | Rha-1 (99.66) | Rha-1 (99.65) | |
| 2 | 75.02 | 70.24 | 70.25 | |
| 3 | 78.39 | 70.39 | 70.40 | |
| 4 | 71.46 | 71.73 | 71.73 | |
| 5 | 78.00 | 69.56 | 69.57 | |
| 6 | 62.60 | 17.82 | 17.83 | |
| OCH3 | 56.86 | 55.77 | 55.69 | |
| OCH3 | 56.02 | |||
| FAB-MS | 389 [M+H] | 515 [M+Na] | 507 [M+H] | 321 [M+H] |
Chemical shift in δ ppm, coupling constant (J) expressed in Hz in parenthesis and measured in the solvent CD3OD (PMG and DHM) and dimethyl sulfoxide (TRR and LRR), taking tetramethylsilane as an internal standard. Fast atom bombardment mass spectrometry (FAB-MS) spectra were determined by nitrobenzyl alcohol as a matrix.
PMG, pinosylvin 3-methoxy-5-O-β-D-glucoside; TRR, taxiresinol 4’-O-α-L-rhamnoside; LRR, lariciresinol 4’-O-α-L-rhamnoside; DHM, dihydromyricetin.