Synthetic studies of neoclerodane diterpenes from Salvia divinorum: semisynthesis of salvinicins A and B and other chemical transformations of salvinorin A.

Salvinorin A, a hallucinogen from the plant Salvia divinorum, is unique as the first non-nitrogenous compound known to bind to opioid receptors. To understand why it selectively targets kappa opioid receptors, researchers systematically altered its structure and tested the effects on receptor binding and activity. This work describes chemical transformations of salvinorin A, including a semisynthesis of salvinicins A and B. It also identifies compound 10a as the first neoclerodane diterpene with delta opioid antagonist activity, providing new tools for studying opioid receptor interactions.

Study at a glance

Abstract

Salvinorin A (1) is a hallucinogenic neoclerodane diterpene isolated from the widely available psychoactive plant Salvia divinorum and is the first example of a non-nitrogenous opioid receptor ligand. At present, there is little information available as to why this compound is selective for kappa opioid receptors. One approach to better understanding the mode of binding of 1 at kappa receptors is to systematically alter the structure of 1 and examine the effects on opioid receptor affinity and activity. Currently, there is a paucity of methods described for the preparation of analogues derived from 1. Here, we report the investigation of several chemical transformations of 1 isolated from S. divinorum. In particular, this work provides a semisynthesis of salvinicins A (2) and B (3) and has identified 10a as the first neoclerodane diterpene with delta opioid antagonist activity.