Binding of methoxy-substituted N1-benzenesulfonylindole analogs at human 5-HT6 serotonin receptors

Indole analog 12c (Ki = 0.8 nM) binds with high affinity at 5-HT6 serotonin receptors; the presence of the methoxy groups results in enhanced affinity and might make an electronic contribution to binding. In contrast, 1,2,3,4-tetrahydrocarbazoles failed to behave in a similar manner and introduction of the methoxy groups resulted in decreased affinity (11c; Ki = 210 nM).