Table 1 The calculated BDEs in gas phase, water and ethanol solvent at the weakest X-H (X=C, O) bond and the proton dissociation enthalpy (PDE) of the lignans.
Comp. | Name | X-H (X=O, C) position | BDEs (X-H, kcal.mol−1) | PDEs (kcal.mol−1) Gas phase | ||
|---|---|---|---|---|---|---|
Gas phase | Water | Ethanol | ||||
1 | Cyclolariciresinol | O4-H | 81.1 | 83.9 | 83.2 | 241.3 |
C7′-H | 79.8 | 83.9 | 83.1 | 240.1 | ||
2 | Secoisolariciresinol | O4-H | 78.6 | 81.8 | 81.1 | 232.1 |
3 | Isoliovil | O4-H | 84.1 | 86.7 | 86.1 | 234.8 |
O4′-H | 85.8 | 86.8 | 86.3 | 236.5 | ||
C7′-H | 82.8 | 86.6 | 85.9 | 233.5 | ||
4 | Matairesinol | O4-H | 85.4 | 87.2 | 86.6 | 230.9 |
O4′-H | 85.1 | 84.0 | 83.6 | 230.5 | ||
5 | Hydroxymatairesinol | O4-H | 85.7 | 87.0 | 86.1 | 232.1 |
O4′-H | 85.8 | 88.0 | 87.4 | 232.3 | ||
C7′-H | 85.0 | 84.4 | 83.8 | 231.5 | ||
6 | Nortrachelogenin | O4′-H | 78.9 | 82.3 | 81.6 | 229.3 |
7 | Pinoresinol | O4-H | 84.3 | 87.0 | 86.3 | 235.7 |
C2-H | 79.6 | 82.7 | 82.1 | 231.0 | ||
8 | α-Conidendrin | O4-H | 84.6 | 86.8 | 85.8 | 233.5 |
O4′-H | 84.0 | 86.5 | 85.8 | 233.0 | ||
C7′-H | 82.0 | 85.8 | 85.1 | 230.9 | ||
9 | Lariciresinol | O4-H | 78.5 | 82.1 | 81.4 | 230.8 |
O4′-H | 78.4 | 81.9 | 81.2 | 230.7 | ||
10 | LignanA | O4-H | 84.9 | 84.0 | 83.6 | 238.5 |
O4′-H | 84.6 | 82.7 | 82.4 | 238.2 | ||
C12-H | 80.9 | 83.6 | 82.9 | 234.5 | ||
