Pip-Tryptamine

pip-T was only briefly mentioned by Alexander Shulgin in his book TiHKAL (Tryptamines I Have Known and Loved). Its properties and effects were not described.

Pharmacodynamics

The affinities (IC₅₀Tooltip half-maximal inhibitory concentration) of pip-tryptamine for serotonin receptors were 600 nM for the serotonin 5-HT_1A receptor, 760 nM for the serotonin 5-HT_2A receptor, and 1,250 nM for the serotonin 5-HT_2B receptor, whereas other serotonin receptors were not reported. The affinity of pip-T for the serotonin 5-HT_2A receptor was about 10-fold lower than that of dimethyltryptamine (DMT) and was about 7-fold lower than that of pyr-tryptamine (pyr-T; N,N-pyrrolidinyltryptamine). Pip-T is a serotonin receptor agonist in the rat uterus with similar potency as DMT, but showed 20-fold lower potency than DMT in the rat fundus strip.

The drug produces hypolocomotion in rodents. In addition, it induces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents. This was blocked by the serotonin 5-HT_2A receptor antagonist ketanserin. Hence, the drug may have hallucinogenic effects in humans. Conversely, pip-T did not produce conditioned place preference (CPP) and was not self-administered, suggesting that it lacks reinforcing properties and misuse potential, similarly to most other tryptamines.

Synthesis

The chemical synthesis of pip-T has been described.

Analogues

Analogues of pip-T include 5-MeO-pip-T, 10,11-secoergoline (α,N-Pip-T), pyr-T, MPMI, SN-22, RU-24,969, and EMD-386088, among others.

mor-Tryptamine

mor-Tryptamine, or mor-T, also known as 3-(2-morpholinoethyl)indole, is the analogue of pip-T with the piperidine ring replaced with a morpholine ring. It was briefly described by Alexander Shulgin in his book TiHKAL (Tryptamines I Have Known and Loved), including its chemical synthesis. The drug was tested by intramuscular injection of 30 mg as the fumarate salt, but produced no effects whatsoever. Accordingly, mor-T was completely inactive as a serotonin receptor agonist in the rat uterus and rat stomach strip. The 5-methoxy derivative of mor-T, 5-MeO-mor-T, is also known, but is not known to have been tested.

Pip-T was first described in the scientific literature by 1959 and was more thoroughly characterized in 1990 and 2020.