Table 1. The known range of thapsigargins found in Thapsia.
| |||
|---|---|---|---|
| Compound | R1 | R2 | |
| 1 | Thapsigargin | O-Oct | But |
| 2 | Thapsigargicin | O-Hex | But |
| 3 | Thapsitranstagin | O-iVal | 2-MeBut |
| 4 | Thapsivillosin A | O-Ang | Sen |
| 5 | Thapsivillosin B | O-Ang | 2-MeBut |
| 6 | Thapsivillosin C | O-Oct | 2-MeBut |
| 7 | Thapsivillosin D | O-6-MeOct | Sen |
| 8 | Thapsivillosin E | O-6-MeOct | 2-MeBut |
| 9 | Thapsivillosin G | O-6-MeHep | 2-MeBut |
| 10 | Thapsivillosin H | O-Ang or Sen | Ang or Sen |
| 11 | Thapsivillosin I | O-Ang | But |
| 12 | Thapsivillosin J | O-IVal | But |
| 13 | Thapsivillosin K | O-Sen | 2-MeBut |
| 14 | Trilobolide | H | (S)-2-MeBut |
| 15 | Nortrilobolide | H | But |
| 16 | Thapsivillosin F | H | Sen |
Ang, angeloyl; Sen, senecioyl; iVal, iso-valeroyl.