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.
Vaccenic acid acid in osteoblasts. Oxidation of omega-7 unsaturated fatty acids on the skin surface, such as palmitoleic acid and vaccenic acid, may be the cause of the phenomenon commonly known as old person smell. Vaccenic acid Vaccenic acid, also known as ("E")-octadec-11-enoic acid is a naturally occurring trans-fatty acid found in the fat of ruminants and in dairy products such as milk, butter, and yogurt. It is also the predominant fatty acid comprising trans fat in human milk. Its IUPAC name is ("E")-11-octadecenoic acid, and its lipid shorthand name is 18:1 "trans"-11. The name was derived from the Latin "vacca" (cow).