Psilocin

Overview
Psilocin,(4-HO-DMT) sometimes called psilocine or psilotsin, is a psychedelic (hallucinogenic) mushroom alkaloid. It is found in most psychedelic mushrooms together with its close congener psilocybin. Psilocin is a Schedule I drug under the Convention on Psychotropic Substances.

Psilocin is almost identical to the chemical structure of the chemical of another known hallucinogen, bufotenin. The only difference is the position of the hydroxyl (OH-) group on the benzene ring — in psilocin, the hydroxyl group is at the 4-position, while in bufotenin it is at the 5-position.

History
The Swiss chemist Albert Hofmann and the laboratory assistant Hans Tscherter from Sandoz isolated psilocin and its phosphate ester psilocybin from Psilocybe mushrooms in 1959 guided by self-administration.

Chemistry
Psilocin can be obtained by dephosphorylation of natural psilocybin under strongly acidic or under alkaline conditions (hydrolysis). One synthetic route uses the Speeter-Anthony tryptamine synthesis starting from 4-hydroxyindole.

Psilocin is relatively unstable in solution due to its phenolic OH group. Under alkaline conditions in the presence of oxygen it immediately forms bluish and dark black degradation products. Similar products are also formed under acidic conditions in the presence of oxygen and Fe3+ ions (Keller's reagent, FeCl3 / MeOH / HCl). Psilocin is an amine and forms salts with acids [citation needed] that are usually more stable upon storage. Psilocin base can be evaporated by heating.

Pharmacology
Psilocybin is rapidly dephosphorylated in the body to psilocin which then acts as a partial agonist at the 5-HT2A serotonin receptor in the brain where it mimics the effects of serotonin (5-HT). Psilocin is an 5-HT1A and 5-HT2A/2C agonist.