Salvinorin A and related diterpenes--biological activity and potential therapeutic uses.
Salvinorin A (SA) is the main active ingredient of Salvia divinorum, a naturally occurring hallucinogen plant from Mexico. Traditionally, herbal preparations obtained from Salvia were used by the Mazatec Indians for their divination rites and the treatment of gastrointestinal disorders. SA is a selective K-opioid receptor agonist, producing antinociception in animals and humans and displaying regulatory effect on colonic function. Studies in humans demonstrated potent hallucinogenic effect of SA. The extensive research on SA and related neoclerodane diterpenes over the past few years resulted in a number of reports on their isolation, synthesis, and pharmacological characterization. In this review we try to summarize, from the pharmacological and synthetic point of view, the structure-activity relationship studies of SA and discuss the possible use of SA and its derivatives as therapeutics.