Table 2.
NMR spectrum data for stremycin B (2), 1H NMR (500 MHz, δ in ppm), 13C NMR (125 MHz, δ in ppm) in MeOD.
| Position | δC, Type | δH (Mult., J in Hz) | HMBC | COSY |
|---|---|---|---|---|
| 1 | 81.8, CH | 4.43, d (3.8) | C-1A, C-2, C-3, C-12b, C-4a | H-2 |
| 2 | 123.1, CH | 5.72, d (3.2) | 3-Me, C-4 | H-1 |
| 3 | 138.7, C | - | - | - |
| 4 | 70.5, CH | 4.17, s | 3-Me, C-3, C-4a, C-12b | - |
| 4a | 76.2, C | - | - | - |
| 5 | 75.9, CH | 5.76, d (6.8) | C-6, COMe | H-6 |
| 6 | 69.8, CH | 4.91, m (6.8) | C-5, C-6a, C-12a | H-5 |
| 6a | 144.5, C | - | - | - |
| 7 | 190.8, C | - | - | - |
| 7a | 115.6, C | - | - | - |
| 8 | 158.7, C | - | - | - |
| 9 | 139.4, C | - | - | - |
| 10 | 134.2, CH | 7.85 d (7.7) | C-8, C-1B, C11a | H-11 |
| 11 | 120.0, CH | 7.61, d (7.7) | C-7a, C-9, C-12 | H-10 |
| 11a | 132.5, C | - | - | - |
| 12 | 187.3, C | - | - | - |
| 12a | 146.7, C | - | - | - |
| 12b | 79.7, C | - | - | - |
| 3-Me | 21.9, CH3 | 1.95, s | C-3, C-4 | - |
| 5-COMe | 173.0, C | - | - | - |
| 20.6, CH3 | 2.02, s | - | - | |
| Sugar A | ||||
| 1A | 100.9, CH | 4.57, d (4.4) | C-1, C-3A, C-5A | H-2A |
| 2A | 30.3, CH2 | 1.32, overlapped; 1.85, m | C-1A | H-1A, H-3A |
| 3A | 78.4, CH | 3.27, m | C-4A | H-4A |
| 4A | 67.5, CH | 3.47, m | - | H-5A |
| 5A | 63.7, CH | 4.10, d (6.5) | - | H-6A |
| 6A | 16.8, CH3 | 1.17, d (6.6) | C-5A | H-5A |
| OMe-3A | 57.7, C | 3.30, s | - | - |
| Sugar B | ||||
| 1B | 72.4, CH | 4.87, m (overlapped) | C-9, C-10 | H-2B |
| 2B | 38.6, CH2 | 1.42, m; 2.49, dd (12.3, 4.6) | C-3B, C-4B | H-1B, H-3B |
| 3B | 82.3, CH | 3.84, m | C-4B, C-1C | H-4B |
| 4B | 76.9, CH | 3.11, dd (11.1, 6.7) | C-3B, C-5B, C-6B | H-5B |
| 5B | 77.7, CH | 3.44, dd (6.9, 3.5) | C-6B | H-6B |
| 6B | 18.8, CH3 | 1.37, d (6.1) | C-5B | - |
| Sugar C | ||||
| 1C | 99.3, CH | 4.77, d (9.9) | C-3B, C-2C | H-2C |
| 2C | 45.6, CH2 | 1.95, overlapped; 1.67, m | C-3C, C-4C | H-1C |
| 3C | 71.5, C | - | - | - |
| 4C | 90.5, CH | 3.18, d (9.6) | Me-3C, C-5C, C-6C, C-1D | H-5C |
| 5C | 72.0, CH | 4.81, d (6.5) | --- | H-6C |
| 6C | 18.5, CH3 | 1.30, d (6.1) | C-5C | H-5C |
| Me-3C | 22.6, CH3 | 1.25, s | C-3C, C-4C | - |
| Sugar D | ||||
| 1D | 104.5, CH | 4.61, d (9.2) | C-4C, C-2D, C-3D | H-2D |
| 2D | 31.4, CH2 | 1.99, m; 1.63, m | - | H-3D |
| 3D | 28.9, CH2 | 2.14, m; 1.59, m | - | H-4D |
| 4D | 73.9, CH | 4.24, dd (9.7, 5.5) | C-6D, CONH2 | H-5D |
| 5D | 75.3, CH | 3.62, m | - | H-6D |
| 6D | 18.2, CH3 | 1.22, d (6.1) | C-5D | - |
| 4D-CONH2 | 159.6, C | - | C-4D | - |