Cinchona is a dried bark obtained from the cultivated trees of Cinchona calisaya, Cinchona ledgeriana, Cinchona officinalis, Cinchona succirubra of the family Rubiaceae.
Cinchona is called as Jesuit’s bark as this bark was identified and used by the Jesuits for its anti-pyretic property. As it was first discovered in Peru it is also known as Peruvian bark.
The cultivation of Cinchona is carried out in the countries like India, Bolivia, Columbia, Ecuador, Peru, Tanzania, Guatemala, Indonesia and Sri Lanka.
In India the cultivation is carried out in Annamalai hills of Coimbatore district and Nilgiri hills of Nilgiri district in Tamil Nadu and in Darjeeling area of West Bengal.
The bark is powdered and extracted with benzene or toulene in the presence of alkali and are extracted with dilute sulphuric acid. When it is made neutral, quinine sulphate separates as it is sparingly soluble. Cinchona bark has slight, characteristic odour and astringent and intensely bitter taste. It is available in the form of quills and curved pieces.
Cinchona bark consists of alkaloids which belong to quinoline group. The important alkaloids are quinine, quinidine, cinchonine and cinchonidine, quinicine, cinchonicine hydroquinine, hydrocinchonidine andhomocinchonidine. Quinidine is also obtained commercially from cuprea bark, Ramijia pendunculata belonging to the family Rubiaceae. Quinine and quinidine form many salts, among their salts, sulphates are more significant. Quinine and quinidine are stereoisomers of each other. Cinchonine and cinchonidine are also isomers of each other. http://www.flickr.com/photos/ebrana/4782981889/ Cinchona also contains quinic acid and cinchotannic acid. It also contains a glycoside called quinovin, tannins and bitter essential oil. Quinine occurs as white crystals and in dark it shows fluorescent properties. It gives blue fluorescence in ultra-violet light.