Simplify the following text for a Grade 10 native English-speaking person.
Original: It was not until 1820 that the active ingredient , quinine , was extracted from the bark , isolated and named by the French chemists Pierre Joseph Pelletier and Joseph BienaimÃ Caventou .
Simplified: It was not until 1820 that the active ingredient , quinine , was extracted from the bark , isolated and named by French chemists .