Table 2.
Diagnostic 13C and 1H chemical shifts (ppm) of sulfo-sialic acid analogues compared to the corresponding phosphonic acids4, and carboxylic acids20.
| C-1 Anomeric | C-2 | H-1 Anomeric | H-2ax | H-2eq | H-5 | Solvent | |
|---|---|---|---|---|---|---|---|
| 7a | 87.0 | 36.4 | 4.28 | 1.79 | 2.45 | 3.63 | CD3OD |
| 7b | 86.7 | 34.3 | 4.70 | 1.92 | 2.62 | 4.25 | CD3OD |
| eqPO3H | 73.6 | 36.2 | 3.75 | 1.70 | 2.24 | 3.49 | CD3OD |
| axPO3H | 71.9 | 34.4 | 4.25 | 1.94 | 2.36 | 3.93 | CD3OD |
| eqCO2H* | 76.8 | 37.8 | 3.87 | 1.56 | 2.36 | 3.58 | D2O |
| axCO2H* | 74.8 | 35.2 | 4.44 | 1.87 | 2.56 | 3.62 | D2O |
*Sialic acid numbering has been changed to assign the anomeric position as 1.