Convenient synthesis and in vitro pharmacological activity of 2-thioanalogs of salvinorins A and B

To study drug-receptor interactions, new thio-derivatives of salvinorin A, an extremely potent natural κ-opioid receptor (KOR) agonist, were synthesized. Obtained compounds were examined for receptor binding affinity. Analogs with the same configuration at carbon atom C-2 as in natural salvinorin A showed higher affinity to KOR than their corresponding epimers.