- a colorless, crystalline alkaloid, C20H24N2O2, isomeric with quinine, obtained from the bark of certain species of cinchona trees or shrubs, used chiefly to regulate heart rhythm and to treat malaria.
- a crystalline alkaloid drug that is an optically active diastereoisomer of quinine: used to treat heart arrhythmias. Formula: C 20 H 24 N 2 O 2
