Cytochrome P450-Catalyzed Biosynthesis of a Dihydrofuran Neoclerodane in Magic Mint (Salvia divinorum)

The hallucinogenic plant, Salvia divinorum, synthesizes neoclerodane diterpenes, such as salvinorins, salvidivins, and salvinicins, which are agonistic or antagonistic to mu- or kappa-opioid receptors. From S. divinorum trichomes, crotonolide G synthase (SdCS; CYP76AH39) was identified. It catalyzes the conversion of kolavenol to a dihydrofuran neoclerodane, crotonolide G. O-18(2)-feeding studies confirmed that SdCS incorporates an aerobic oxygen into crotonolide G, rather than forming a cation at C16 that is trapped by the alcohol at C15. Structural modeling of SdCS accompanied by site-directed mutagenesis established the importance of V367 and F479 residues in substrate-binding. The dihydrofuran neoclerodane can serve as a unique lead structure for drug development.