Mitraphylline

Mitraphylline, an oxindole derivative, is an active alkaloid in the leaves of the tree Mitragyna speciosa, commonly known as kratom. As a non-narcotic constituent, it also occurs to a significant amount in the bark of Uncaria tomentosa (Cat’s Claw) along with a number of isomeric alkaloids. Due to its structural similarity to mitragynine and 7-hydroxymitragynine from kratom, effects on mu and delta opiate receptors as well as NMDA-antagonistic actions have been postulated.