Quinine is a naturally occurring alkaloid, isolated from the bark of the cinchon
ID: 502600 • Letter: Q
Question
Quinine is a naturally occurring alkaloid, isolated from the bark of the cinchona tree and possesses antipyretic, antimalarial, analgesic, and anti-inflammatory properties. It has a bitter taste and is now mainly used as an additive to tonic water. Its pseudo-enantiomer, quinidine, also isolated from the cinchona bark, only possesses antiarrhythmic properties. a. During the 17^th century, in order to prepare a treatment for malaria-induced shivering, the bark was first dried, ground to a fine powder, and then mixed into a liquid, commonly wine, which was then drunk. By 1820, the French chemists Pelletier and Caventou had developed a process to isolate pure quinine powder from the bark. Based on your experience with isolating caffeine from tea, describe how you might try and isolate pure quinine from the bark of the cinchona tree in the lab. b. Once in hand, list two ways to determine that the powder you isolated is quinine and not a different alkaloid from the bark.Explanation / Answer
small amount of bark powder can be treated with calcium hydroxide and sodium hydroxide .The mixture can be heated and from resulting solution the quinine can be extracted using suitable organic solvent like dichloromethane.
Wheather you have got quinine or not can be easilt tested usinng fluorescence.
Quinine shows intense fluorescence in acid (for eg sulphuric). Take small sample in a cuvette and put in uv cabinet annd obbserve fluorescence under 254 and 365 nm. You will see intense fluorescnce. Compare this with fluorescence of tonic wate which also contains quinine.