Psilocybin biosynthesis in S. cerevisiae. The heterologous biosynthetic pathway begins with the native production of tryptophan, which itself is derived from metabolites produced via glycolysis, the pentose phosphate pathway, and the shikimate pathway. DAHP, 3-deoxy-D-arabinoheptulosonate 7-phosphate; EPSP, 5-enolpyruvoyl-shikimate 3-phosphate; Glyc. 3-P, glyceraldehyde 3-phosphate; Ala, alanine; Glu, glutamate; Tyr, tyrosine; Phe, phenylalanine. Multiple arrows represent multiple enzymatic reactions grouped for simplicity.