The cinchona alkaloids are a family of natural products which can be isolated from cinchona trees. There are about 40 different species of cinchona tree all of which are indigenous to the slopes of the Andes, however because of their commercial importance, several of these species are now widely cultivated in many tropical countries, including Indonesia.
The most abundant of these alkaloids is quinine and this, along with quinidine, cinchonine and cinchonidine, can comprise up to 16% by mass of the tree bark. The bark is usually harvested by beating the tree trunks and then removing the material that peels away. The tree can partially regenerate its bark over a few years, and several cycles of removing the bark and letting it grow back can be achieved before the trees have to be uprooted and replaced by new ones.