Tetrahydropyridinylindoles (THPIs) are a group of chemical compounds related to the tryptamines.Cornfield, L. J. (1990). Characterization of structure-activity relationships for serotonin receptors coupled to adenylate cyclase. The University of Arizona. http://hdl.handle.net/10150/185101 "The work discussed in this chapter extends the previous study by examining relationships between structure and intrinsic activity at 5-HT1A receptors in a larger series of tetrahydropyridinyl analogs, specifically 3-(1,2,5,6-tetrahydropyridin-4-yl)indoles (4-THPI) and 3-(1,2,5,6-tetrahydropyridin-3-yl)indoles (3-THPI). [...]" They can be subdivided into 3-(1,2,5,6-tetrahydropyridin-4-yl)indoles (4-THPIs or simply THPIs) and 3-(1,2,5,6-tetrahydropyridin-3-yl)indoles (3-THPIs). 3-THPIs are cyclized tryptamines and include RS134-49, RU-28253, and NEtPhOH-THPI, whereas 4-THPIs are not technically tryptamines but are closely related, with examples including THPI, RU-24969 (5-MeO-THPI), EMD-386088, MTHPI, tepirindole (RU-27592), Lu 35-138, and LY-367265. Tetrahydropyridinylindoles of both of the preceding groups are known to act as serotonin receptor modulators.
See also Substituted tryptamine § Related compounds Cyclized tryptamine Piperidinylindole
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