CINCHONA Cinchona spp. Rubiaceae
San: Cinchona, Kunayanah Hin: Kunain Mal: Cinchona, Quoina Tam: Cinchona
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).