Cinchonine and quinine were isolated by French chemists Pierre Joseph Pelletier and Jean Baptiste Boussingault in 1820. They obtained these alkaloids from the bark of the cinchona tree, which is native to South America. Cinchonine is the primary alkaloid found in cinchona bark, while quinine is a minor component. These alkaloids have potent antimalarial activity and are still used today to treat this disease.