Table 2.
The chemical shifts from of 1H and 13C NMR (nuclear magnetic resonance) spectra of chlorogenic acid (5-CQA, 5-O-caffeoylquinic acid) and alkali metal chlorogenates (5-CQAs), δ [ppm].
| Proton No. | 5-CQA [2] | 5-CQAs | Carbon No. | 5-CQA | 5-CQAs | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Li | Na | K | Rb | Cs | Li | Na | K | Rb | Cs | ||||
| H2eq | 1.80 | 1.68 | 1.73 | 1.72 | 1.61 | 1.60 | C1 | 73.6 | 75.8 | 75.2 | 75.2 | 75.2 | 75.2 |
| H2ax | 2.03 | 1.99 | 1.99 | 1.98 | 1.98 | 1.97 | C2 | 37.3 | 39.5 | 39.5 | 39.5 | 39.5 | 39.5 |
| H3 | 3.94 | 3.92 | 3.91 | 3.90 | 3.88 | 3.88 | C3 | 68.2 | 71.4 | 71.4 | 71.5 | 71.6 | 71.6 |
| H4 | 3.58 | 3.48 | 3.49 | 3.48 | 3.47 | 3.48 | C4 | 70.5 | 71.5 | 71.6 | 71.6 | 71.7 | 71.6 |
| H5 | 5.08 | 5.17 | 5.17 | 5.17 | 5.16 | 5.16 | C5 | 71.0 | 73.2 | 73.3 | 73.4 | 73.5 | 73.5 |
| H6eq | 1.96 | 1.81 | 1.81 | 1.81 | 1.90 | 1.81 | C6 | 36.4 | 38.0 | 38.1 | 38.2 | 38.2 | 38.2 |
| H6ax | 2.01 | 1.85 | 1.87 | 1.87 | 1.94 | 1.94 | C7 | 175.0 | 176.5 | 176.7 | 176.5 | 176.2 | 176.0 |
| H7 | 12.41 | C1′ | 125.7 | 125.4 | 125.5 | 125.4 | 124.4 | 124.5 | |||||
| H2′ | 7.04 | 7.06 | 7.07 | 7.08 | 7.01 | 7.02 | C2′ | 114.9 | 114.5 | 114.7 | 114.7 | 114.0 | 114.1 |
| H3′ | 9.13 | C3′ | 145.6 | 145.8 | 145.8 | 145.9 | 146.3 | 146.2 | |||||
| H4′ | 9.56 | C4′ | 148.4 | 148.8 | 148.5 | 148.8 | 150.2 | 150.0 | |||||
| H5′ | 6.77 | 6.75 | 6.75 | 6.72 | 6.69 | 6.70 | C5′ | 115.9 | 115.9 | 115.8 | 115.9 | 115.6 | 115.6 |
| H6′ | 6.98 | 6.97 | 6.97 | 6.96 | 6.93 | 6.93 | C6′ | 121.5 | 121.2 | 121.2 | 121.2 | 121.5 | 121.4 |
| H7′ | 7.43 | 7.46 | 7.44 | 7.44 | 7.44 | 7.44 | C7′ | 145.0 | 144.7 | 144.6 | 144.7 | 144.9 | 144.9 |
| H8′ | 6.16 | 6.22 | 6.22 | 6.22 | 6.21 | 6.22 | C8′ | 114.4 | 114.5 | 114.6 | 114.5 | 113.7 | 114.1 |