Contains 4–14% quinoline alkaloids (quinine, quinidine, cinchonine, cinchonidine) and up to 8% catechin tannins.
The bark is used for the preparation of extracts and isolation of alkaloids such as quinine, which was the first antimalarial. Quinine is also used as a reference standard for bitterness in pharmacopoeial testing, and in beverages like tonic. The alkaloid quinidine was used as an antiarrhythmic (a sodium-channel blocker).
It is the whole or cut dried bark, appearing as tubular or gutter-shaped pieces. The exterior surface is dull and grayish-brown, and the interior is striated, dark red-brown. The fracture is short and fibrous.
The drug is listed in the pharmacopoeia.
In pulverized drug under the microscope we can see:
Thin-walled cork cells with red-brown content
Phloem fibers with rounded ends
Idioblasts with microscopic oxalate crystals (“crystal sand”)
