psilocybin

psilosybiini A hallucinogenic alkaloid, C12H15N2O·H2PO3, present in several species of Central American mushroom and producing effects similar to LSD.
2005: The problem of the mushroom supply was solved straight away when Leary learned from a graduate student named George Litwin that a chemist at the Sandoz Corporation, Dr. Albert Hofmann, had recently synthesized the psychoactive molecule of the mushroom, calling it psilocybin. — Martin Torgoff, Cant Find My Way Home'' (Simon & Schuster 2005, p. 70)