Table 1.
1H- and 13C-NMR data for akanthopyrones A–D (1–4, Methanol-d4).
| Pos | 1 a | 2 | 3 | 4 | ||||
|---|---|---|---|---|---|---|---|---|
| δH (J in Hz) | δC, Type | δH (J in Hz) | δC, Type | δH (J in Hz) | δC, Type | δH (J in Hz) | δC, Type | |
| 2 | - | 165.1, C | - | 167.1, C | - | 167.9, C | - | 167.8, C |
| 3 | - | 104.4, C | - | 105.1, C | - | 102.1, C | - | 105.1, C |
| 4 | - | 167.4, C | - | 170.8, C | - | 169.0, C | - | 170.8, C |
| 5 | 6.76, s | 94.9, CH | 7.06, s | 96.6, CH | 7.00, s | 96.8, CH | 7.06, s | 96.6, CH |
| 6 | - | 165.3, C | - | 167.8, C | - | 164.9, C | - | 167.0, C |
| 7 | 4.51, b dd (7.3, 4.7) | 76.4, CH | 4.67, dd (7.3, 4.6) | 77.1, CH | 4.65, dd (7.5, 4.9) | 77.0, CH | 4.66, dd (7.3, 4.7) | 77.1, CH |
| 8 | 1.74, m; 1.84, m | 34.1, CH2 | 1.76, m; 1.86, m | 35.4, CH2 | 1.76, m; 1.85, m | 35.4, CH2 | 1.76, m; 1.86, m | 35.4, CH2 |
| 9 | 1.38, m | 24.9, CH2 | 1.44, m | 25.9, CH2 | 1.43, m | 25.9, CH2 | 1.43, m | 25.9, CH2 |
| 10 | 1.29, b m | 29.2, CH2 | 1.35, b m | 30.6, CH2 | 1.35, b m | 30.5, CH2 | 1.35, b m | 30.5, CH2 |
| 11 | 1.27, b m | 29.3,c CH2 | 1.32, b m | 30.7, c CH2 | 1.32, b m | 30.6,c CH2 | 1.32, b m | 30.6, c CH2 |
| 12 | 1.25, b m | 29.4,c CH2 | 1.30, b m | 30.9, c CH2 | 1.30, b m | 30.7,c CH2 | 1.30, b m | 30.7, c CH2 |
| 13 | 1.25, b m | 29.5,c CH2 | 1.30, b m | 30.8, c CH2 | 1.30, b m | 30.9,c CH2 | 1.30, b m | 33.2, CH2 |
| 14 | 1.25, b m | 29.6,c CH2 | 1.30, b m | 30.7, c CH2 | 1.30, b m | 30.8,c CH2 | 1.30, b m | 23.9, CH2 |
| 15 | 1.25, b m | 31.8, CH2 | 1.34, b m | 27.1, CH2 | 1.35, b m | 27.1, CH2 | 0.90, t (7.1) | 14.6, CH3 |
| 16 | 1.29, b m | 22.6, CH2 | 1.52, m | 33.8, CH2 | 1.53, m | 33.8, CH2 | 4.44, s | 54.2, CH2 |
| 17 | 0.87, t (6.9) | 14.1, CH3 | 3.54, t (6.7) | 63.2, CH2 | 3.54, t (6.8) | 63.2, CH2 | 3.99, s | 58.0, CH3 |
| 18 | 4.51, b s | 54.3, CH2 | 4.44, s | 54.2, CH2 | 1.87, s | 8.6, CH3 | - | - |
| 19 | 3.93, s | 56.9, CH3 | 3.99, s | 58.1, CH3 | 3.96, s | 57.7, CH3 | - | - |
| β-4-O-methyl-d-glucopyranose | ||||||||
| 1′ | 4.29, d (7.6) | 100.6, CH | 4.26, d (7.9) | 102.7, CH | 4.25, d (7.9) | 102.6, CH | 4.25, d (7.9) | 102.7, CH |
| 2′ | 3.43, dd (7.6, 9.2) | 73.6, CH | 3.29, dd (7.9, 9.2) | 75.3, CH | 3.28, dd (7.9, 9.2) | 75.4, CH | 3.28, dd (7.9, 9.2) | 75.4, CH |
| 3′ | 3.54, dd (9.2, 8.8) | 76.6, CH | 3.43, dd (9.2, 8.8) | 78.3, CH | 3.43, dd (9.1, 9.1) | 78.3, CH | 3.43, dd (9.1, 9.1) | 78.4, CH |
| 4′ | 3.21, dd (8.8, 9.5) | 79.1, CH | 3.09, dd (9.2, 9.5) | 81.1, CH | 3.09, dd (9.1, 9.5) | 81.1, CH | 3.09, dd (9.1, 9.5) | 81.1, CH |
| 5′ | 3.26, m | 75.4, CH | 3.23, m | 77.4, CH | 3.22, m | 77.4, CH | 3.22, m | 77.4, CH |
| 6′ | 3.74, dd (12.2, 4.3) 3.89, dd (12.2, 2.4) | 61.8, CH2 | 3.68, dd (11.8, 5.3) 3.84, dd (11.8, 2.0) | 62.5, CH2 | 3.68, dd (11.8, 5.4) 3.83, dd (11.8, 2.0) | 62.5, CH2 | 3.68, dd (11.8, 5.4) 3.83, dd (11.8, 2.0) | 62.5, CH2 |
| OMe | 3.57, s | 60.8, CH3 | 3.56, s | 60.9, CH3 | 3.55, s | 60.9, CH3 | 3.55, s | 61.0, CH3 |
1 and 2 were measured at 500 MHz (13C 125 MHz); 3 and 4 were measured at 700 MHz spectrometer (13C 175 MHz); a in CDCl3, b overlapping signals, c assignment may be interchanged.