Mitragyna speciosa?

Mitragyna speciosa is a tropical tree in primarily located in South East Asia. The tree and leaves from the tree are prepared and called kratom . The leaves are often chewed or used to make tea. It is used at a low dose to help fight fatigue. However, it can also be used as a narcotic at high dosages. Mitragynine is a structure of the leaves that is a psychoactive alkaloid.
The chemical structure of mitragynine contains carbon, hydrogen, oxygen, and nitrogen. The structure contains 3 chiral centers. In the picture below, the arrows point to the chiral centers present in the structure:

Resources:
Kratom (Mitragyna speciosa)
http://www.emcdda.europa.eu/publications/drug-profiles/kratom