San: Cinchona, Kunayanah
Hin: Kunain Mal: Cinchona, Quoina
Importance: Cinchona, known as Quinine, Peruvian or Crown bark tree is famous for the antimalarial drug ‘quinine’ obtained from the bark of the plant. The term cinchona is believed to be derived from the countess of cinchon who was cured of malaria by treating with the bark of the plant in 1638. Cinchona bark has been valued as a febrifuge by the Indians of south and central America for a long time. Over 35 alkaloids have been isolated from the plant; the most important among them being quinine, quinidine, cinchonine and cinchonidine. These alkaloids exist mainly as salts of quinic, quinovic and cinchotannic acids. The cultivated bark contains 7-10% total alkaloids of which about 70% is quinine. Similarly 60% of the total alkaloids of root bark is quinine. Quinine is isolated from the total alkaloids of the bark as quinine sulphate. Commercial preparations contain cinchonidine and dihydroquinine. They are useful for the treatment of malarial fever, pneumonia, influenza, cold, whooping couphs, septicaemia, typhoid, amoebic dysentery, pin worms, lumbago, sciatica, intercostal neuralgia, bronchial neuritis and internal hemorrhoids. They are also used as anesthetic and contraceptive. Besides, they are used in insecticide compositions for the preservation of fur, feathers, wool, felts and textiles. Over doses of these alkaloids may lead to deafness, blindness, weakness, paralysis and finally collapse, either comatose or deleterious. Quinidine sulphate is cardiac depressant and is used for curing arterial fibrillation.
Distribution: Cinchona is native to tropical South America. It is grown in Bolivia, Peru, Costa Rica, Ecuador, Columbia, Indonesia, Tanzania, Kenya, Zaire and Sri Lanka. It was introduced in 1808 in Guatemala,1860 in India, 1918 in Uganda, 1927 in Philippines and in 1942 in Costa Rica. Roy Markham introduced the plant to India. The first plantation was raised in Nilgiris and later on in Darjeeling of West Bengal. The value of the tree was learnt by Jessuit priests who introduced the bark to Europe. It first appeared in London pharmacopoeia in 1677 (Husain, 1993).
Botany: The quinine plant belongs to the family Rubiaceae and genus Cinchona which comprises over 40 species. Among these a dozen are medicinally important. The commonly cultivated species are C. calisaya Wedd., C. ledgeriana Moens, C. officinalis Linn., C. succirubra Pav. ex Kl., C. lancifolia and C. pubescens. Cinchona species have the chromosome number 2n=68. C. officinalis Linn. is most common in India. It is an evergreen tree reaching a height of 10-15m. Leaves are opposite, elliptical, ovate- lanceolate, entire and glabrous. Flowers are reddish-brown in short cymbiform, compound cymes, terminal and axillary; calyx tubular, 5-toothed, obconical, subtomentose, sub-campanulate, acute, triangular, dentate, hairy; corolla tube 5 lobed, densely silky with white depressed hairs, slightly pentagonal; stamens 5; style round, stigma submersed. Fruit is capsule ovoid-oblong; seeds elliptic, winged margin octraceous, crinulate-dentate (Biswas and Chopra, 1982).
Agrotechnology: The plant widely grows in tropical regions having an average minimum temperature of 14 C. Mountain slopes in the humid tropical areas with well distributed annual rainfall of 1500-1950mm are ideal for its cultivation. Well drained virgin and fertile forest soils with pH 4.5-6.5 are best suited for its growth. It does not tolerate waterlogging. Cinchona is propagated through seeds and vegetative means. Most of the commercial plantations are raised by seeds. Vegetative techniques such as grafting, budding and softwood cuttings are employed in countries like India, Sri Lanka, Java and Guatemala. Cinchona succirubra is commonly used as root stock in the case of grafting and budding. Hormonal treatment induces better rooting. Seedlings are first raised in nursery under shade. Raised seedbeds of convenient size are prepared, well decomposed compost or manure is applied , seeds are broadcasted uniformly at 2g/m2, covered with a thin layer of sand and irrigated. Seeds germinate in 10-20 days. Seedlings are transplanted into polythene bags after 3 months. These can be transplanted into the field after 1 year at 1-2m spacing. Trees are thinned after third year for extracting bark , leaving 50% of the trees at the end of the fifth year. The crop is damaged by a number of fungal diseases like damping of caused by Rhizoctoria solani, tip blight by Phytophthora parasatica, collar rot by Sclerotiun rolfsii, root rot by Phytophthora cinnamomi, Armillaria mellea and Pythium vexans. Field sanitation, seed treatment with organo mercurial fungicide, burning of infected plant parts and spraying 1% Bordeaux mixture are recommended for the control of the diseases (Crandall, 1954). Harvesting can be done in one or two phases. In one case, the complete tree is uprooted, after 8-10 years when the alkaloid yield is maximum. In another case, the tree is cut about 30cm from the ground for bark after 6-7 years so that fresh sprouts come up from the stem to yield a second crop which is harvested with the under ground roots after 6-7 years. Both the stem and root are cut into convenient pieces, bark is separated, dried in shade, graded, packed and traded. Bark yield is 9000-16000kg/ha (Husain, 1993).
Properties and activity: Over 35 alkaloids have been isolated from Cinchona bark, the most important among them are quinine, quinidine, cinchonine, cinchonidine, cinchophyllamine and idocinchophyllamine. There is considerable variation in alkaloid content ranging from 4% to 20%. However, 6-8% yield is obtained from commercial plantations. The non alkaloidal constituents present in the bark are bitter glycosides, -quinovin, cinchofulvic, cinchotannic and quinic acids, a bitter essential oil possessing the odour of the bark and a red coloring matter. The seed contains 6.13% fixed oil. Quinine and its derivatives are bitter, astringent, acrid, thermogenic, febrifuge, oxytocic, anodyne, anti-bacterial, anthelmintic, digestive, depurative, constipating, anti pyretic, cardiotonic, antiinflammatory, expectorant and calcifacient (Warrier et al, 1994; Bhakuni and Jain, 1995).