8-epi-Salvinorin B: crystal structure and affinity at the κ opioid receptor

摘要: There have been many reports of epimerization salvinorins at C-8 under basic conditions, but little evidence has presented to establish the structure these compounds. We report here first crystal an 8-epi-salvinorin or derivative: title compound, 2b. The lactone adopts a boat conformation with furan equatorial. Several lines suggest that proceeds via enolization rather than previously proposed indirect mechanism. Consistent general trend in related compounds, compound showed lower affinity kappa opioid receptor natural epimer salvinorin B (2a). 8-epi-acid 4b no affinity.