Table 2.
1H NMR Chemical shifts (δ) of compounds 1–10.
| Compounds | OH (δ) | Methine (δ) | α to the Diketone (δ) | β to the Diketone (δ) | Methoxyl (δ) | Acetyl (δ) | Benzyl (δ) | Aromatic (δ) |
|---|---|---|---|---|---|---|---|---|
| DAC | 16.12 | 6.20 | 6.99 | 7.66 | 3.85 | 2.28 | - | 7.16–7.52 |
| DACH4 | 15.53 | 5.78 | 2.77 | 2.85 | 3.74 | 2.23 | - | 5.78–7.00 |
| DiMeOC | 16.27 | 5.80 | 6.47 | 7.58 | 3.91–3.89 | - | - | 6.85–7.05 |
| DiBcOC | 16.30 | 6.11 | 6.48 | 7.59 | 3.84 | - | 5.14 | 7.34–7.59 |
| PhCurcu | 16.11 | 6.21 | 6.96 | 7.67 | - | - | - | 7.73 |
| DAC-Cu | - | - | - | - | - | 2.27 | 3.85 | - |
| DACH4-Cu | - | - | - | - | - | 4.01 | - | - |
| DiMeOC-Cu | - | - | - | - | - | 4.01 | - | - |
| DiBcOC-Cu | - | - | - | - | - | 3.86 | - | - |
| PhCurcu-Cu | - | - | 6.91 | 7.66 | - | - | - | - |