Caventou and Pelletier had isolated strychnine in 1818 and Brucine in 1819, both from Nux vomica.

In 1820, the pair had isolated cinchonine and quinine, the active anti-malarial ingredient in the bark of cinchona tree. (Quinine sulfate will later prove to be an important remedy for the disease malaria.)

Neither of the partners had chosen to patent their discovery of this compound, releasing it for all to use.

In 1821, they had isolated caffeine, and in 1823 they discover nitrogen in alkaloid compounds.

Other compounds they have isolated include colchicine (1820) and veratrine.