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.
Disulfiram-like drug Disulfiram-like drug A disulfiram-like drug is a drug that causes hypersensitivity to alcohol leading to nausea, vomiting, flushing, dizziness, throbbing headache, chest and abdominal discomfort, and general hangover-like symptoms among others. These effects are caused by accumulation of acetaldehyde, a major but toxic metabolite of alcohol formed by the enzyme alcohol dehydrogenase. The reaction has been variously termed a "disulfiram-like reaction", "alcohol intolerance", and "acetaldehyde syndrome". The prototypical drug of this group is disulfiram (brand name Antabuse), which acts as an acetaldehyde dehydrogenase inhibitor, preventing the metabolism of acetaldehyde into acetic acid, and is used in the treatment of alcoholism.