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.
Erucic acid surfactants or lubricants, and can be used as a precursor to biodiesel fuel. Derivatives of erucic acid have many further uses, such as behenyl alcohol (CH(CH)OH), a pour point depressant (enabling liquids to flow at a lower temperature), and silver behenate, for use in photography. The name 'erucic' means: of or pertaining to "Eruca"; which is a genus of flowering plants in the family Brassicaceae. It is also the Latin for colewort, which today is better known as arugula. Erucic acid is produced naturally (together with other fatty acids) across a great range of green plants, but especially so in