Cinchona Bark

CINCHONA BARK (or cinchona bark), Cortex Chinae, more correctly Cortex Cinchonae (Pharmacopoeia), is obtained mainly from cultivated cinchona trees and only in a small amount from wild cinchonas: Cinchona ledgeriana Moens, Cinchona succirubra Pavon, Cinchona officinalis Hooker fib. and some others; all belong to the madder family (fam. Rubiaceae). The family Cinchona calisaya, which provides bark with a small content of quinine, belongs to the same family. Pharmacopoeia VII requires Cinchona bark from cultivated Cinchona succirubra Pavon, in which after drying at 100° there must be at least 6.5% alkaloids. Cinchona bark has the form of grooved pieces 20-60 cm, rarely up to 1 m long and 2-4 mm thick, externally gray, often silvery-white; in places where the periderm is scraped off, it is light brown; wrinkled, with lenticels with longitudinal and transverse cracks. The inner surface of the bark is smooth, longitudinally fibrous, reddish-brown; in young bark there is a distinctly yellowish tint. The taste of the bark is bitter. When powder of Cinchona bark is distilled in a dry test tube, a tar-like mass of carmine-red color collects on the cold walls of the test tube in the form of tiny droplets (Grahe's test). The alkaloid quinine in Cinchona bark lies in the parenchyma tissue. If the cambial layer of the bark of cinchona trees develops especially abundantly, then in such cases Cinchona bark is rich in quinine. Practically this is achieved by partial removal of Cinchona bark from the stems of cinchonas while preserving the cambium and the nearest phloem to it, from which new bark arises. The homeland of cinchona trees is considered to be South America, where between 10° north and 19-22° south latitude on the slopes of the Cordillera mountains cinchonas grow wild in forests at an altitude of 800-3,000 m. Some tribes of the indigenous population have long known the antimalarial properties of Cinchona bark; Europeans became aware of them in 1638, when the wife of the Viceroy of Peru, the Countess del Cinchon, recovered from fever after taking Cinchona bark. Since 1640 Cinchona bark has been brought to Europe and quickly gained recognition as the best remedy at that time for marsh fever and spread under the name Pulvis Comitissae (Countess's powder), as well as under the name Pulvis patrium (Fathers' powder) and others. In 1820 Pelletier and Caventou isolated the alkaloid from Cinchona bark. In 1865 the English merchant Ledger (Charles Ledger) managed, with the help of a cascarilliero (cinchona bark collector), to obtain seeds of a cinchona producing excellent bark. Ledger sold the cinchona seeds to the Netherlands, which two years later had 20,000 young cinchonas on its plantations. After that, cinchonas began to be cultivated in Java, Ceylon, India, South America, Mexico, and Jamaica. In the USSR, the cultivation of cinchona tree is carried out in the Batumi Botanical Garden. In the Sukhumi nursery of VIR, work has been carried out to convert the perennial culture of the cinchona tree into an annual plant, the mass of which is used to obtain alkaloids. Cinchona bark contains crystalline alkaloids - quinine, quinidine, cinchonine, cinchonidine, homocinchonidine, hydroquinine, hydroquinidin, cinchonamine, chinamine, conchinamine, hydroquinine, hydroquinidine, heiramidine, heiramidin, concheiramidine, concheiramidin, aricine, quassonine, conquinonine, conquinonidine, dicinchonine, homochinine, dichinidine; amorphous alkaloids - pericine, quassamine, quassanoidin, javanin and others, still little studied, the mixture of which, obtained during industrial production of quinine, forms a resinous brown mass called quinoidin; acids - cinchonic, cinchonodubinic, cinchonic; glycosides - α- and β-cinchovin; coloring substances - chinacrasin, cinchonin, chinovit; in insignificant quantities - sugar, wax, starch, flobaphen, resin, lignin, humic acids, calcium oxalate, mineral substances. The medical application of Cinchona bark is conditioned not only by quinine but also by other constituent parts of Cinchona bark, such as cinchonidubinic acid and cinchonic acid, which have a disinfecting and astringent action. Wiechowski points out that some malaria patients, whose disease did not respond to treatment with quinine, recovered under the combined influence of all the constituent parts of Cinchona bark, introduced internally in the form of Pulvis corticis Chinae in separate doses from 10.0 to 30.0 and up to 60.0 a day. Powder of Cinchona bark is given to patients as a tooth powder, counting on the mechanical astringent and disinfecting action of such powder. Cold infusion of Cinchona bark is used as a bitter, as a stomachic tonic, strengthening; it contains less active principles but is better tolerated than hot infusion. Infusions of Cinchona bark are also used externally - for washing the head. Acid decoction of Cinchonae (Pharmacopoeia VII) is used for rinsing the mouth in tetanus and in putrid softening of the gums; it can also be used for enemas. Extractum Cinchonae (Pharmacopoeia VII) - a thick extract obtained with the aid of alcohol; Extr. Chinae aquosum of a thick consistency and Extr. Chinae fluidum liquid are used internally mainly as bitters for action as a stomachic. Tinctura Cinchonae (Pharmacopoeia VII) and Tinctura Cinchonae composita (Pharmacopoeia VII) are taken internally 1.0-4.0 or in drops mixed with wine or with mixtures as a strengthening (stomachic), tonic, roborans. Tinctura Chinae composita is part of the Botkin drops (stomachic). Lit. - see lit. to the article Quinine.