| Purine Nucleotides | Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA. | 59 | 597 | Details |
| Purine-Nucleoside Phosphorylase, antagonists & inhibitors | Not Available | 5 | 11 | Details |
| Purinergic Agents | Compounds that act on PURINERGIC RECEPTORS or influence the synthesis, storage, uptake,... more | 20 | 153 | Details |
| Purinergic Agonists | Compounds that bind to and activate PURINERGIC RECEPTORS. | 5 | 25 | Details |
| Purinergic Antagonists | Drugs that bind to and block the activation of PURINERGIC RECEPTORS. | 15 | 128 | Details |
| Purinergic P1 Receptor Agonists | Compounds that bind to and stimulate PURINERGIC P1 RECEPTORS. | 5 | 25 | Details |
| Purinergic P1 Receptor Antagonists | Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS. | 8 | 70 | Details |
| Purinergic P2 Receptor Antagonists | Compounds that bind to and block the stimulation of PURINERGIC P2 RECEPTORS. | 6 | 33 | Details |
| Purinergic P2X Receptor Agonists | Not Available | 1 | 1 | Details |
| Purinergic P2X Receptor Antagonists | Compounds that bind to and block the stimulation of PURINERGIC P2X RECEPTORS. Included ... more | 1 | 1 | Details |
| Purinergic P2Y Receptor Antagonists | Compounds that bind to and block the stimulation of PURINERGIC P2Y RECEPTORS. Included ... more | 5 | 38 | Details |
| Purines | A series of heterocyclic compounds that are variously substituted in nature and are kno... more | 230 | 1268 | Details |
| Purinones | Cyclic compounds that include atoms other than carbon in their ring structure. | 71 | 279 | Details |
| Putrescine, analogs & derivatives | Not Available | 1 | 6 | Details |
| Putrescine, antagonists & inhibitors | Not Available | 0 | 0 | Details |
| Pyrans | Cyclic compounds that include atoms other than carbon in their ring structure. | 214 | 846 | Details |
| Pyrazines | A heterocyclic aromatic organic compounds with the chemical formula C4H4N2. | 4 | 37 | Details |
| Pyrazoles | Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMID... more | 85 | 340 | Details |
| Pyrazolone Derivatives | Not Available | 1 | 2 | Details |
| Pyrazolones | Compounds with a five-membered heterocyclic ring with two nitrogens and a keto OXYGEN. ... more | 17 | 83 | Details |
| Pyrenes | A group of condensed ring hydrocarbons. | 1 | 3 | Details |
| Pyrethrines | Not Available | 4 | 19 | Details |
| Pyrethrines, Incl. Synthetic Compounds | Not Available | 3 | 21 | Details |
| Pyrethrins | The active insecticidal constituent of CHRYSANTHEMUM CINERARIIFOLIUM flowers. Pyrethrin... more | 3 | 22 | Details |
| Pyridazines | Six-membered rings with two adjacent nitrogen atoms also called 1,2-diazine. | 22 | 88 | Details |