FIGURE 1.

The proposed biosynthetic pathway of DCA (A) and the established biosynthetic route to major cannabinoids (B). Both pathways consist of (1) polyketide formation, (2) prenylation, and (3) cyclization steps. The polyketide formation steps of each pathway are enclosed in dashed squares. ^aIn the absence of OAC, the pentyl tetra-β-ketide intermediate is spontaneously cyclized to olivetol via decarboxylative aldol condensation. Abbreviations used are: OAC, olivetolic acid cyclase; TKS, tetraketide synthase.