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.
Gamma-Hydroxybutyric acid to be illegal. In Chile, GHB is a controlled drug under the law (psychotropic substances and narcotics). In Norway and in Switzerland, GHB is considered a narcotic and is only available by prescription under the trade name Xyrem (Union Chimique Belge S.A.). Sodium oxybate is also used therapeutically in Italy under the brand name Alcover for treatment of alcohol withdrawal and dependence. Gamma-Hydroxybutyric acid γ-Hydroxybutyric acid (GHB), also known as 4-hydroxybutanoic acid, is a naturally occurring neurotransmitter and a psychoactive drug. It is a precursor to GABA, glutamate, and glycine in certain brain areas. It acts on the GHB receptor