Cinchona Bark

It consists of the dried bark of the stem and root of various species, races and hybrids of Cinchona (Rubiaceae).

Commercial Importance

There are about a dozen different cinchona species in commerce. Cinchona and its alkaloids particularly quinine were of great importance for use in the treatment of malaria before World War II. With the introduction of synthetic drugs, its importance declined but it remains of great economic importance and salts of quinine and quinidine are included in most pharmacoepias. Today it has re-emerged as suitable for the treatment of Plasmodium falciparum infections resistant to chloroquine and other synthetic antimalarials. Quinidine, the diastereoisomer of quinine, is employed for the prophylaxis of cardiac arrhythmias and for the treatment of atrial fibrillation. It also has antimalarial properties and like quinine it is effective against chloroquine-resistant organisms.

Species and Distribution

There are over 36 known species and hybrids of cinchona. They are now cultivated in many parts of the world including Bolivia, Gautemala, India, Indonesia, Zaire, Tanzania and Kenya. Commercially valuable bark is obtained from three main species based on favourable range of alkaloids present. They are

  • C. succirubra – Cultivated in Belgian Congo and Kenya, it provides what is known as ‘red bark’ and contains 5% to 7% total alkaloids.
  • C. ledgeriana – Also cultivated in Belgian Congo and Kenya, it provides ‘brown bark’ and contains 5% to 14% total alkaloids.
  • C. calisaya – This and C. ledgeriana are natives of Southern Peru and Bilivia. Now also cultivated in India and Indonesia, it yields 4% to 7% total alkaloids. Selected hybrids can yield upto 17% total alkaloids.

Harvest

The bark was originally obtained by felling wild trees, which led to their destruction. Today production of cinchona bark is a highly specialized section of tropical agriculture employing high-yielding strains, grafting and other techniques. Bark is collected from 6 to 9-year-old trees (with the maximal alkaloid content) during rainy season, sun dried and then dried by artificial heat before being coarsely powdered. It is then processed for the separation of alkaloids.


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