Natural product to modern discovery of their active ingredients and eventually to the development of new drugs. A large number of currently prescribed drugs have been either directly derived from or inspired by natural products. A few representative examples are listed below. Some of the oldest natural product based drugs are analgesics. The bark of the willow tree has been known from antiquity to have pain relieving properties. This is due to presence of the natural product salicin which in turn may be hydrolyzed into salicylic acid. A synthetic derivative acetylsalicylic acid better known as aspirin is a widely used pain reliever.
Quinic acid Quinic acid Quinic acid is a cyclitol, a cyclic polyol, and a cyclohexanecarboxylic acid. It is a colorless solid that can be extracted from plant sources. Quinic acid is implicated in the perceived acidity of coffee. The compound is obtained from cinchona bark, coffee beans, the bark of "Eucalyptus globulus". It is a constituent of the tara tannins. Urtica dioica is another common source. It is made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee. This substance was isolated for the first time in 1806 by French pharmacist Nicolas Vauquelin and