| Cinchona | |
|---|---|
| Cinchona pubescens - flowers | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Gentianales |
| Family: | Rubiaceae |
| Subfamily: | Cinchonoideae |
| Tribe: | Cinchoneae[1] |
| Genus: | Cinchona L. |
| Species | |
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about 38 species; see text |
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Cinchona or Quina is a genus of about 38 species in the family Rubiaceae, native to the tropical Andes forests of western South America.[2] They are medicinal plants, known as sources for quinine and other compounds.
The name of the genus is due to Carolus "Carl" Linnaeus, who named the tree in 1742 after a Countess of Chinchón, the wife of a viceroy of Peru, who, in 1638, was introduced by native Quechua healers to the medicinal properties of cinchona bark. Stories of the medicinal properties of this bark, however, are perhaps noted in journals as far back as the 1560s–1570s [3].
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The Cinchona plants are large shrubs or small trees with evergreen foliage, growing 5–15 metres (16–49 ft) in height. The leaves are opposite, rounded to lanceolate and 10–40 cm long.
The flowers are white, pink or red, produced in terminal panicles. The fruit is a small capsule containing numerous seeds.
The medicinal properties of the cinchona tree were originally discovered by the Quechua (Inca) peoples of Peru and Bolivia, and long cultivated by them as a muscle relaxant to halt shivering due to low temperatures. After Spanish colonization of the Americas, the Jesuit missionaries were the first to bring the Jesuit's bark cinchona compound to Europe in 1632. To maintain their monopoly on cinchona bark, Peru and surrounding countries began outlawing the export of cinchona seeds and saplings beginning in the early 19th century.
Meanwhile, also in the 19th century the plant's seeds and cuttings were smuggled out for new cultivation at cinchona plantations in colonial regions of tropical Asia, notably by the British to the British Raj and Ceylon (present day India and Sri Lanka), and by the Dutch to Java in the Dutch East Indies (present day Indonesia). [4]
As a medicinal herb, cinchona bark is also known as Jesuit's bark or Peruvian bark. The bark is stripped from the tree, dried, and powdered for medicinal uses. The bark is medicinally active, containing a variety of alkaloids. They include the anti-malarial compound quinine which interferes with the reproduction of malaria-causing protozoa. Another is quinidine, an antiarrhythmic.
Cinchona species are used as food plants by the larvae of some Lepidoptera species including The Engrailed, The Commander, and members of the genus Endoclita including E. damor, E. purpurescens and E. sericeus.
According to legend, the first European ever to be cured from malaria fever was the countess of Chinchón, the wife of the Spanish Luis Jerónimo de Cabrera, 4th Count of Chinchón - the Viceroy of Peru. The namesake Chinchón is a small town in central Spain. In the Viceroyalty of Peru, the court physician was summoned and urged to save the countess from the waves of fever and chill that were threatening her life, but every effort failed to relieve her. At last the physician administered some medicine which he had obtained from the local Indians, who had been using it for similar syndromes. The countess survived the malarial attack and reportedly brought the cinchona bark back with her when she returned to Europe in the 1640s.
The Italian botanist Pietro Castelli wrote a pamphlet noteworthy as being the first Italian publication that mentions the cinchona. By the 1630s (or 1640s, depending on the reference), the bark was being exported to Europe. In the late 1640s, the method of use of the bark was noted in the Schedula Romana, and in 1677 the use of the bark was noted in the London Pharmacopoeia
Charles II called upon Mr Robert Talbor, who had become famous for his miraculous malaria cure. Because at that time the bark was in religious controversy, Talbor gave the king the bitter bark decoction in great secrecy. The treatment gave the king complete relief from the malaria fever. In return, he was offered membership of the prestigious Royal College of Physicians.
In 1679 Talbor was called by the King of France, Louis XIV, whose son was suffering from malaria fever. After a successful treatment, Talbor was rewarded by the king with 3,000 gold crowns. At the same time he was given a lifetime pension for this prescription. Talbor, however, was asked to keep the entire episode secret.
After Talbor's death, the French king found this formula: six drams of rose leaves, two ounces of lemon juice and a strong decoction of the cinchona bark served with wine. Wine was used because some alkaloids of the cinchona bark are not soluble in water, but are soluble in [the ethanol in] wine.
The birth of homeopathy was based on cinchona bark testing. The founder of homeopathy, Dr. Samuel Hahnemann, when translating the Cullen's Materia medica, noticed that Dr. Cullen wrote that Peruvian bark was known to cure intermittent fevers. [5] Dr. Hahnemann took daily a large, rather than homeopathic, dose of Peruvian bark. After two weeks, he said he felt malaria-like symptoms. This idea of "like cures like" was the starting point of his writings on "Homeopathy". Hahnemann's symptoms are believed to be the result of a hypersensitivity to Cinchona bark on his part.[6]
In 1738, Sur l'arbre du quinquina, a paper written by Charles Marie de La Condamine, a member of the expedition that was sent to Peru to determine the length of a degree of the meridian arc in the neighbourhood of the equator, was published by the French Academy of Sciences. In it he identified three separate species.[7]
In 1742, on the basis of a specimen received from La Condamine, Linnaeus named the tree Quinquina condaminiae and established a new genus, which he termed Cinchona quinquina condaminiae. In 1753 he described Cinchona officinalis as a separate species.[8]
The bark was very valuable to Europeans in expanding their access to and exploitation of resources in far off colonies, and at home. Bark gathering was often environmentally destructive, destroying huge expanses of trees for their bark, with difficult conditions for low wages that did not allow the indigenous bark gatherers to settle debts even upon death.[9]
Further exploration of the Amazon Basin and the economy of trade in various species of the bark in 18th century is captured by the extract from a book by Lardner Gibbon:
"...this bark was first gathered in quantities in 1849, though known for many years. The best quality is not quite equal to that of Yungas, but only second to it. There are four other classes of inferior bark, for some of which the bank pays fifteen dollars per quintal. The best, by law, is worth fifty-four dollars. The freight to Arica is seventeen dollars the mule load of three quintals. Six thousand quintals of bark have already been gathered from Yuracares. The bank was established in the year 1851. Mr. [Thaddäus] Haenke mentioned the existence of cinchona bark on his visit to Yuracares in 1796."(Source: Exploration of the Valley of the Amazon, by Lieut. Lardner Gibbon, USN. Vol.II, Ch.6, pp. 146-47.)
In 1860, a British expedition to South America led by Clements Markham brought back smuggled Cinchona seeds and plants, which were introduced in several areas of the British Raj in India and Sri Lanka. In Sri Lanka, it was planted in the Hakgala Botanical Garden in January 1861.[10] James Taylor, the pioneer of tea planting in Sri Lanka, was one of the pioneers of Cinchona cultivation.[11] By 1883 about 64,000 acres (260 km2) were in cultivation in Sri Lanka, with exports reaching a peak of 15 million pounds in 1886.
In 1865, "New Virginia" and "Carlota Colony" were established in Mexico by former American Civil War Confederate Matthew Fontaine Maury. Post-American Civil War confederates were enticed there by Maury, now the Imperial Commissioner of Immigration for Emperor Maximillian of Mexico, and Archduke of Habsburg. All that survives today of those two colonies are the flourishing groves of cinchonas, the quinine-producing trees purchased by Maury using seeds purchased from England. These seeds were the first to be introduced into Mexico. [12]
The bark of trees in this genus is the source of a variety of alkaloids, the most familiar of which is quinine, an anti-fever 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[13] called red cinchonic,[14] cinchono-fulvic acid or cinchona red.[15]
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