Olivetol (Oli)

Olivetol is biosynthesized by a polyketide synthase-type reaction from hexanoyl-CoA and three molecules of malonyl-CoA by an aldol condensation of a tetraketide intermediate. In 2009, Taura et al. was able to clone a type III PKS named olivetol synthase (OLS) from Cannabis sativa. This PKS is a homodimeric protein that consists of a 385 amino acid polypeptide with a molecular mass of 42,585 Da that has high sequence similarity (60-70%) identity to plant PKS's. The data from Taura’s study of OLS's enzyme kinetics show that OLS catalyzes a decarboxylative-aldol condensation to produce olivetol. This is similar to stilbene synthase’s (STS) mechanism for converting p-coumaroyl-CoA and malonyl-CoA to resveratrol. Although olivetol is the decarboxylated form of OLA, it is highly unlikely that OLS produces olivetol from OLA. Crude enzyme extracts prepared from flowers and leaves did not synthesize olivetolic acid, but only yielded olivetol.