Psilocybin and Psilocin

With the help of this reliable test on human subjects, the active principle could be isolated, concentrated, and transformed into a chemically pure state by means of the newest separation methods. Two new substances, which I named psilocybin and psilocin, were thereby obtained in the form of colorless crystals.
These results were published in March 1958 in the journal Experientia, in collaboration with Professor Heim and with my colleagues Dr. A. Brack and Dr. H. Kobel, who had provided greater quantities of mushroom material for these investigations after they had essentially improved the laboratory cultivation of the mushrooms.
Some of my coworkers at the time - Drs. A. J. Frey, H. Ott, T. Petrzilka, and F. Troxler - then participated in the next steps of these investigations, the determination of the chemical structure of psilocybin and psilocin and the subsequent synthesis of these compounds, the results of which were published in the November 1958 issue of Experientia. The chemical structures of these mushroom factors deserve special attention in several respects. Psilocybin and psilocin belong, like LSD, to the indole compounds, the biologically important class of substances found in the plant and animal kingdoms. Particular chemical features common to both the mushroom substances and LSD show that psilocybin and psilocin are closely related to LSD, not only with regard to psychic effects but also to their chemical structures. Psilocybin is the phosphoric acid ester of psilocin and, as such, is the first and hitherto only phosphoric-acid-containing indole compound discovered in nature. The phosphoric acid residue does not contribute to the activity, for the phosphoric-acid-free psilocin is just as active as psilocybin, but it makes the molecule more stable. While psilocin is readily decomposed by the oxygen in air, psilocybin is a stable substance.
Psilocybin and psilocin possess a chemical structure very similar to the brain factor serotonin. As was already mentioned in the chapter on animal experiments and biological research, serotonin plays an important role in the chemistry of brain functions. The two mushroom factors, like LSD, block the effects of serotonin in pharmacological experiments on different organs. Other pharmacological properties of psilocybin and psilocin are also similar to those of LSD. The main difference consists in the quantitative activity, in animal as well as human experimentation. The average active dose of psilocybin or psilocin in human beings amounts to 10 mg (0.01 g); accordingly, these two substances are more than 100 times less active than LSD, of which 0.1 mg constitutes a strong dose. Moreover, the effects of the mushroom factors last only four to six hours, much shorter than the effects of LSD (eight to twelve hours).

from Tihkal by Alexander and Ann Shulgin:

Psilocybin one of the main psychoactive compounds in magic mushrooms. The active dose of psilocybin is 3-30 mg. The effects are psychotomimetic; psilocybin is considered a psychedelic drug. Duration: 4-7 hours. Chemically speaking psilocybin is a tryptamine and an alkaloid. Psilocybin is the posphate ester of psilocin and the more chemically stable of the two compounds. Because of its greater molecular weight psilocybin is less potent than psilocin. Other chemical names for psilocybin are: 4-HO-DMT Phosphate Esther; TRYPTAMINE,4-HYDROXY-N,N-DIMETHYL,4PHOSPHORYLOXY. It is believed that after taking, psilocybin is easily converted into psilocin and that the pharmacological properties of both compounds are the same.