Cinchona Trees

Cinchona, or "quinine bark" is one of the rainforest most famous plants, for many centuries it has been known to have medicinal properties. It is especially known for being the plant which the antimalarial drug, quinine, is extracted from.

The genus cinchona has approximately 40 species of evergreen trees and shrubs which are indigenous to the Sub Andean jungles of south America. The trees can reach up to between 15 and 20 metres in height and have pink, white or yellow flowers.

Not all the plants in the cinchona genus have quinine bark. The species which quinine is extracted from are: cinchona officinalis, cinchona calisaya, cinchona pubescens and cinchona ledgeriana.

The powdered bark from these tree was originally known as 'Jesuit powder' after the Jesuit missionaries working in Peru. Theses missionaries are thought to have discovered the medicinal properties of this bark. But for religious reasons when the bark was brought over to Europe it s name was changed to cinchona bark or quinine bark.

Legend states that the name cinchona comes from the countess of Chinchon, who was cured in 1638 of a malaria type fever by using the bark of the cinchona tree. It was the Countess Chinchon who first introduced cinchona bark to European medicine in 1940. It is known that cinchona bark made it officially into the London Pharmacopoeia in 1677.

In 1820 Pelletier and Caventou manage to extract quinine and cinchondine from cinchona bark. Since then pure quinine has mainly been used for medical purposes instead of powdered cinchona bark.

There are many cinchona alkaloids which can be extracted from cinchona bark. The four, which have the most commercial use, are Quinine, Cinchonidine, Quinidine and Cinchonine. These can all be extracted from the species cinchona ledgeriana

R = OMe Quinine R = H Cinchonidine			R = OMe Quinidine R = H Cinchonine

All four of these molecules have are least one stereogenic centre. From the structures above it is possible to see the Quinine and Quinidine are stereoisomers and so to are Cinchonidine and Cinchonine. For many years people didn't know how to separate the isomers so racemic compound where often used instead.