Toxic Fungi of Western North America

by Thomas J. Duffy, MD

Psilocybin and psilocin toxins

Dr. Albert Hoffman at Sandoz isolated the active compounds: first psilocybin and then its dephosphorylated form, psilocin. Psilocybin was the first phosphorylated indole found in nature. Because of the rapid enzymatic conversion of psilocybin to psilocin, psilocin is the toxin actually producing effects in humans. Psilocin mimics the effect of the neurotransmitter, serotonin, by strongly attaching to its receptors and provoking an excessive serotonin-like effect. Normal serotonin effects include regulation of circadian rhythms and of vasocontriction. Excessive stimulation of serotonin receptors, however, can produce high blood pressure, rapid pulse, sensory distortions and hallucinations.

Psilocybin
Figure 10. Psilocybin

Many psilocybes blue with bruising or cutting, apparently a reaction catalyzed by cytochrome oxidase. This reaction in hallucinogenic genera corresponds roughly with the amount of psilocin. The exact compound producing this bluing reaction remains to be isolated, although it appears to be a quinone derivative.