Nantenine is an alkaloid found in the plant Nandina domestica as well as some Corydalis species. It is an antagonist of both the α1-adrenergic receptor and the serotonin 5-HT2A receptor, and blocks both the behavioral and physiological effects of MDMA in animals. See also References 5-HT2A antagonists Alpha-1 blockers Antidotes Aporphine alkaloids Phenol ethers