CBGA

CBGA (cannabigerolic acid, C₂₂H₃₂O₄) is the central biosynthetic intermediate — the "mother cannabinoid" — from which the principal cannabinoid acids diverge. It is formed by condensation of geranyl pyrophosphate with olivetolic acid (itself produced from hexanoyl-CoA via a tetraketide synthase and the polyketide cyclase olivetolic acid cyclase, OAC) catalyzed by a prenyltransferase variously called CBGAS or aromatic prenyltransferase (Fellermeier & Zenk, 1998, FEBS Letters 427:283; Gagne et al., 2012, PNAS 109:12811; Luo et al., 2019, Nature 567:123). CBGA is then oxidatively cyclized by distinct FAD-dependent synthases — THCAS, CBDAS, or CBCAS — to yield THCA, CBDA, or CBCA respectively. The chemotypic dominance of a cultivar (I, II, or III) is determined principally by allelic variation at the loci encoding these synthases. Evidence for independent pharmacology: preclinical only. → See also: THCA, CBDA, CBC, Decarboxylation.