Cinchona genus is the source of a variety of alkaloids, the most familiar of which is quinine, an antipyretic (antifever) agent especially useful in treating malaria. Cinchona alkaloids include: They find use in organic chemistry as organocatalysts in asymmetric synthesis. Alongside the alkaloids, many cinchona barks contain cinchotannic acid, a particular tannin, which by oxidation rapidly yields a dark-coloured phlobaphene called red cinchonic, cinchono-fulvic acid or cinchona red. In 1934, efforts to make malaria drugs cheap and effective for use across countries led to the development of a standard called "totaquina" proposed by the Malaria Commission of the League of Nations.
Bark bread bark is the only part of a tree trunk that is actually edible, the remaining bark and wood is made up of cellulose which animals, including humans, cannot digest. The dried and ground inner bark was added in proportions like 1/4th to 1/3rd "bark flour" to the remaining grain flour. Erik Pontoppidan, the Bishop of Bergen, Norway, in the mid 18th century, recommended using elm, as it helped the often crumbly bark bread hold together better. The bark will, however, add a rather bitter taste to the bread, and give particularly white bread an unappetizing grey-green hue. Another problem is