| Member | Definition | Role |
|---|
| 1,5-dihydroxyisoquinoline | An isoquinolinol that is isoquinoline in which the hydrogens at positions 1 and 5 are replaced by hydroxy groups. | isoquinoline-1,5-diol |
| 2-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline | An isoquinolinol that is norsalsolinol substituted by a methyl group at position 2. It is present in normal human brain and also identified in the cerebrospinal fluid of patients with Parkinson's disease. | N-methylnorsalsolinol |
| norsalsolinol | An isoquinolinol that is 1,2,3,4-tetrahydroisoquinoline substituted by hydroxy groups at positions 6 and 7. It is present in the dopamine-rich areas of the human brain, including the substantia nigra. | norsalsolinol |
| reticulin | | reticuline |
| tetrahydropapaveroline | | norlaudanosoline |