Phytochemical characterization of the leaves of Mitragyna speciosa grown in U.S.A.

Mitragyna speciosa (Rubiaceae) has traditionally been used in the tropical regions of Asia, Africa and Indonesia as a substitute for opium. Indole alkaloids are the most common compounds that have been isolated. We investigated the constituents of the leaves of M. speciosa that was grown at the University of Mississippi. Several alkaloids were isolated, including ajmalicine, corynantheidine, isomitraphylline, mitraphylline, paynantheine, isocorynantheidine, 7-hydroxymitragynine and mitragynine, but their percentages were lower than those in a commercial Thai sample of "kratom". In addition, we isolated the flavonoid epicatechin, a saponin daucosterol, the triterpenoid saponins quinovic acid 3-O-beta-D-quinovopyranoside, quinovic acid 3-O-beta-D-glucopyranoside, as well as several glycoside derivatives including 1-O-feruloyl-beta-D-glucopyranoside, benzyl-beta-D-glucopyranoside, 3-oxo-alpha-ionyl-O-beta-D-glucopyranoside, roseoside, vogeloside, and epivogeloside. This is the first report of the last group of compounds having been isolated from a Mitragyna species. Biological studies are currently underway to test these compounds for opioid activity.