is an opioid analgesic
that is an analogue
of the natural product Salvinorin A
. It was discovered in 2005 during structure-activity relationship studies into neoclerodane diterpenes, the family of chemical compounds of which Salvinorin A is a member.
Unlike Salvinorin A which is a selective κ-opioid agonist
with no significant μ-opioid receptor
affinity, herkinorin is a μ-opioid agonist with more than 100x higher μ-opioid affinity and 50x lower κ-opioid affinity compared to Salvinorin A. Herkinorin is a semi-synthetic compound, made from Salvinorin B, which is most conveniently made from Salvinorin A by deacetylation, as while both Salvinorin A and Salvinorin B are found in the plant Salvia divinorum
, Salvinorin A is present in larger quantities. Read more...