Table 1.
Comparison of 13C NMR chemical shifts in guanine incubated in concentrated sulfuric acid for two different time periods. All NMR data were obtained at room temperature.
| Guanine | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 13C | ||||||||||
| Solvent | C2 (ppm) | C4 (ppm) | C5 (ppm) | C6 (ppm) | C8 (ppm) | |||||
| 11 October 2022 | 6 November 2023 | 11 October 2022 | 6 November 2023 | 11 October 2022 | 6 November 2023 | 11 October 2022 | 6 November 2023 | 11 October 2022 | 6 November 2023 | |
| 81% D2SO4/19% D2O | 150.36 | 150.37 | 136.33 | 136.34 | 108.22 | 108.22 | 150.55 | 150.56 | 137.11 | 137.10 |
| 88% D2SO4/12% D2O | 150.28 | 150.28 | 136.26 | 136.27 | 108.13 | 108.14 | 150.42 | 150.44 | 137.22 | 137.21 |
| 94% D2SO4/6% D2O | 150.23 | 150.23 | 136.22 | 136.22 | 108.01 | 108.01 | 150.26 | 150.28 | 137.38 | 137.36 |
| 98% D2SO4/2% D2O | 150.13 | 150.12 | 136.17 | 136.18 | 107.90 | 107.90 | 150.19 | 150.22 | 137.53 | 137.53 |