Salvinorin A, a potent and selective kappa opioid receptor agonist, produces intense hallucinogenic effects when smoked. The smoke of salvinorin A contains at least eight neoclerodane diterpene derivatives, which were isolated and identified using spectroscopic methods. The major chemical transformations occurring during smoking include epimerizations, eliminations, and rearrangements, leading to these novel compounds.
Salvinorin A, the main active ingredient of Salvia divinorum, is a potent and selective κ opioid receptor (KOPR) agonist. Researchers synthesized a series of C-2 halogenated analogs of salvinorin A as molecular probes to investigate the binding pocket at the C-2 position, particularly the effects of α versus β configuration. Binding and functional studies showed that β isomers generally bind better than α isomers, except for iodinated analogs. None of the C-2 halogenated analogs improved KOPR binding affinity compared to the parent compound. Functional assays characterized one analog, 6b, as a partial agonist with a maximum effect of 46% of the full agonist U50,488H at 250 nM. Affinity to the kappa receptor increased with atomic radius (I>Br>Cl>F), consistent with halogen bonding interactions.