5-Methoxytryptamine (5-MT), also known as mexamine, is a tryptamine derivative closely related to the neurotransmitters serotonin and melatonin. 5-MT has been shown to occur naturally in the body in low levels. It is biosynthesized via the deacetylation of melatonin in the pineal gland.
5-MT acts as a full agonist at the 5-HT1, 5-HT2, 5-HT4, 5-HT6, and 5-HT7 receptors. It has no affinity for the 5-HT3 receptor and it should also be noted that its affinity for the 5-HT1E receptor is very weak in comparison to the other 5-HT1 receptors. Its affinity for the 5-HT5A receptor is unknown.
Measured affinity for some receptors (not a complete list):5-HT1B receptors (Ki = 35 nM)
5-HT1D receptors (Ki = 7.3 nM)
5-HT1E receptors (Ki = 3151 nM)
5-HT1F receptors (Ki = 1166 nM)
5-HT2A receptors (Ki = 295 nM)
5-HT2B receptors (Ki = 16.4 nM)
5-HT2C receptors (Ki = 52.48 nM)
5-HT4 receptors (Ki = 501.18 nM)
5-HT6 receptors (Ki = 69.18 nM)
5-HT7 receptors (Ki = 5.01 nM)