Quinine is a white powdery substance obtained from the bark of the cinchona tree. The word “quinine” has its roots from the Peruvian Indian word “kina”, which means “bark of the tree”. Historically, quinine was used as treatment for malaria, and some other conditions. Today, many anti-malarial drugs still contain quinine, but many other substances are now available for malaria treatment.
Quinine was introduced in Europe in the 1600s by Jesuit missionaries from South America. It was known then as the “miracle bark” or “fever tree”, as it proved to be effective in the treatment of fevers associated with malaria. For decades, quinine was the only known drug to be effective against malaria. And it was only in the 1820s, when quinine was isolated in crystalline form by J.B. Caventou and P.J. Pelletier. By 1944, synthetic quinine was made by R.B. Woodward and W. Doering.
Quinine is a large and complex molecule, and the most important alkaloid in the cinchona bark. Its action involves interfering with the reproduction and growth of “plasmodium vivax”, the parasite carried by mosquitoes and found in malaria. Literally, quinine causes these parasites to disappear from the bloodstream, thereby alleviating symptoms of the disease. However, a relapse of symptoms may occur when quinine treatment is stopped. Since not all parasites are killed during treatment, some of them re-invade the bloodstream and cause the symptoms to appear once again. With treatment from quinine not being permanent, many other alternatives were sought after World War II. Some examples of which are chloroquine and chloroguanide.
In its pure form, quinine powder is white or colorless with a sharp bitter taste. Tonic water, originally developed as a prophylactic anti-malarial drug, got it’s bitter taste from quinine. Today, many gins and tonics still contain quinine for its bitter flavor. And aside from anti-malarial drugs, quinine is also used for the treatment of muscle cramps.