5-Methoxyharmalan
5-Methoxyharmalan, also known as 5-methoxy-1-methyl-4,9-dihydro-3H-β-carboline, is a serotonin receptor modulator of the β-carboline family. It is a cyclized tryptamine analogue of 4-MeO-DMT and a positional isomer of 6-methoxyharmalan and harmaline.
Pharmacology
The drug shows high affinity for the serotonin 5-HT2A and 5-HT2C receptors. It had higher affinity for these receptors than any other assessed β-carboline, with 1.7–4.6-fold, 57–58-fold, and >73–116-fold the affinity of harmine, harmaline, and tetrahydroharmine for the serotonin 5-HT2A receptor, respectively. However, like harmaline and 6-methoxyharmalan, 5-methoxyharmalan showed no agonist or antagonist activity at the serotonin 5-HT2A receptor in terms of phosphatidylinositol hydrolysis in vitro at concentrations of up to 10,000nM. It is unclear whether the serotonin 5-HT2A receptor is involved in the hallucinogenic or other psychoactive effects of β-carbolines.5-Methoxyharmalan showed no affinity for the melatonin receptors. The 1-demethyl analogue of 5-methoxyharmalan shows high affinity for the imidazoline I2 receptor and the α2 receptor, whereas 5-methoxyharmalan itself was not assessed.