3-Hydroxy-4-methoxyindolomorphinans as delta opioid selective ligands

Previous studies showed that 4-hydroxy-3-methoxyindolomorphinans had variable delta opioid affinity and selectivity. Herein, we show that the 3,4-dimethoxy analogs possessed similar low affinity, whereas the 3-hydroxy-4-methoxy analogs showed excellent delta opioid affinity and selectivity comparable with the parent indolomorphinans.