Binding of β-carbolines at imidazoline I2 receptors: a structure-affinity investigation

Abstract A series of ring-substituted (i.e., methoxy and bromo) 3,4-dihydro- and 1,2,3,4-tetrahydro-β-carbolines was examined at I 2 imidazoline receptors, as was the effect of ring-opening, ring-expansion, and translocation of the piperidinyl nitrogen atom. Several analogues were identified that bind with K i 2 sites and with reduced affinity at α 2 -adrenergic receptors, and 1,2,3,4-tetrahydro-γ-carbolines were identified as a novel class of I 2 imidazoline receptor ligand.