Willow bark, aspirin from

The most common NSAID is aspirin, or acctylsalicvlic acid, whose use goes back to the late 1800s. It had been known from before the time of Hippocrates in 400 bc that fevers could be lowered by chewing the bark of willow trees. The active agent in willow bark was found in 1827 to be an aromatic compound called salicin, which could be converted by reaction with water into sal- icy I alcohol and then oxidized to give salicylic acid. Salicylic acid... 

No drugs have been a more faithful companion to man throughout his history than salicylates, the forebears of aspirin. About 3,500 years ago the Ebers Papyrus recommended the application of a decoction of leaves of myrtle to the abdomen and back to get rid of rheumatic pains. Hippocrates championed the juices of the poplar tree and willow bark to treat fever and labor pains. These plants and trees are abimdant in compounds derived from salicylic acid, which gets its name from them (in Latin salix is a willow tree). For thousands of years on all continents they have helped to... 

Aspirin Extracted from the bark of willow tree, aspirin was used for the treatment of fever. 

Salicin is an (9-glycoside of a phenol, namely salicyl alcohol. Salicin is a natural antipyretic and analgesic found in willow bark, and is the template from which aspirin (acetylsalicylic acid, see Box 7.13) was developed. Prunasin from cherry laurel is an example of a cyanogenic glycoside, hydrolysis of which leads to release of toxic HCN (see Box 7.7). It is the (9-glucoside of the alcohol mandelonitrile, the trivial name for the cyanohydrin of benzaldehyde. It is the further hydrolysis of mandelonitrile that liberates HCN. 

Aspirin (Figure 15.12) is one of the most frequendy used painkillers in the world. It is also able to reduce inflammation and fever and a low dose taken on a daily basis over the age of 50 may prevent heart attacks. It is derived from another acid, salicylic acid, which can be obtained from willow bark. Salicylic acid has the same medicinal properties as aspirin and has been known since 1829. Salicylic acid, however, caused stomach bleeding. The conversion of salicylic acid to aspirin reduced these problems, but aspirin still has some adverse effects on the stomach if taken in excess. 

SAM-dependent methylation of salicylic acid. The salicyl alcohol derivative salicin, found in many species of willow (Salix species Salicaceae), is not derived from salicylic acid, but probably via glucosylation of salicylaldehyde and then reduction of the carbonyl (Figure 4.27). Salicin is responsible for the analgesic and antipyretic effects of willow barks, widely used for centuries, and the template for synthesis of acetylsalicylic acid (aspirin) (Figure 4.27) as a more effective analogue. 

In the 1800s, doctors, pharmacists, and scientists began to examine herbal remedies more closely. They began to identify the active ingredients in medicinal plants and to isolate and purify those substances. For example, the French pharmacist H. Leroux purified the drug salicin, the precursor of aspirin, from the bark of the willow tree in 1829. 

M. Viktorin, The remedy from willow-bark 100 years of aspirin , LaborPraxis, 1999 (July-August), 82-85 [in German],... 

Willow bark. The bark of the white willow tree (Salix alba) has been used as a pain and fever reducer for centuries. The main active ingredient in willow bark is salicin, which the body converts to salicylic acid, a substance that acts like aspirin. In fact, the first stable form of aspirin (acetylsalicylic acid) was made from a related herb called meadowsweet. Salicylic acid inhibits... 

Willow bark is a source of acetylsalicylic acid or aspirin, which is used to treat headaches and fever. This is just one of the many medicinal compounds derived from plants. 

Salix alba, S.viminalis) contain salicylic acid derivatives in their bark. Preparations of willow bark were used from antiquity in the 19th century, salicylic acid was isolated as the active principle of this folk remedy. This simple acid still enjoys use as an external agent (keratolytic action) but is no longer taken orally for the treatment of pain, fever, and inflammatory reactions. Acetylation of salicylic acid (introduced around 1900) to yield acetylsali-cylic acid (ASA, Aspirin ) improved oral tolerability. 

Other tamarind t bioavailability of aspirin. Meadow sweet and willow bark contain salicylates leading to t effects of aspirin. Feverfew is considered to inhibit the release of serotonin from platelets... 

Recall from Chapter 2 that aspirin (acetylsalicylic acid) is a synthetic carboxylic acid, similar in structure to salicin, a naturally occurring compound isolated from willow bark, and salicylic add, found in meadowsweet. 

C. Only aspirin can be isolated from willow bark. 

Many drugs are based on natural products. Aspirin (above) is a chemical derivative of a compound isolated from willow bark (near left). Extracts of willow bark had been long known to have medicina properties. The active compound was isolated, modified, and, beginning in 1899, packaged for consumers (far left). [Far left Used with permission of Bayer Corporation. Near (eft Image Ideas/ Picture Quest.]... 

No drug is as widely used as aspirin. Observers at least as far back as Hippocrates ( 400 B.C.) have noted the use of extracts from the bark and leaves of the willow tree for pain relief. In 1829, a mixture called salicin was isolated from willow bark. Subsequent analysis identified salicylic acid as the active component of this mixture. Salicylic acid was formerly used to treat pain, but this compound often irritated the stomach. Several investigators... 

It was not until the late 18th and early 19th centuries that an analytical investigation of the active components of medicinal plants and herbal remedies was pursued. This resulted in the discovery of alkaloids such as atropine, morphine, codeine, and papaverine, which eventually became the major constituents of many modem analgesic and cardiac medicines. The discovery of aspirin (from Willow bark), the cannabinoids (from cannabis sct- ya), and digitalis (from foxglove leaf) also came many years, in some cases thousands of years, after these remedies were being used for pain relief, sedation, and dropsy (5-9). 

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