| Active principles | Rating | Bibliogr. | Expand | |
|---|---|---|---|---|
| 1 | Heterocyclic Compounds, 2-Ring | 100 | + | |
| 2 | Heterocyclic Compounds, 1-Ring | 82 | + | |
| 3 | Pyrans | 30 | + | |
| 4 | Alkaloids | 21 | + | |
| 5 | Heterocyclic Compounds with 4 or More Rings | 17 | + | |
| 6 | Heterocyclic Compounds, 3-Ring | 11 | + | |
| 7 | Heterocyclic Compounds, Bridged-Ring | 6 | + | |
| 8 | Acids, Heterocyclic | 2 | + | |
| 9 | Heterocyclic Oxides | 1 | + |