  quinine (,  or  ) is a natural white crystalline alkaloid having antipyretic (fever-reducing), antimalarial, analgesic (painkilling), and anti-inflammatory properties and a bitter taste. it is a stereoisomer of quinidine, which, unlike quinine, is an antiarrhythmic. quinine contains two major fused-ring systems: the aromatic quinoline and the bicyclic quinuclidine. quinine occurs naturally in the bark of the cinchona tre
Alcohols Alkenes Bitter_compounds Phenol_ethers Quinine Quinolines Quinuclidines World_Health_Organization_essential_medicines