(-)-9-Hydroxycorynantheidine
(-)-9-Hydroxycorynantheidine (9-O-Desmethyl mitragynine), the 9-demethyl analogue of Mitragynine, is a selective and partial agonist of μ-opioid receptor. (-)-9-Hydroxycorynantheidine inhibits electrically stimulated twitch contraction in guinea-pig ileum.