Salicin

Salicin is a naturally occurring glycoside found primarily in the bark of willow trees (Salix species) and in some related plants. It consists of salicyl alcohol linked to a glucose moiety as a beta-D-glucoside, and its chemical formula is C13H18O7.

In the body, salicin is hydrolyzed to salicyl alcohol and glucose. The salicyl alcohol is then oxidized to salicylic acid, the active metabolite responsible for many of the effects attributed to salicylates. The pharmacological activity of salicin largely derives from salicylic acid, which can inhibit the synthesis of prostaglandins and thereby exert analgesic, antipyretic, and, to a lesser extent, anti-inflammatory effects compared with aspirin.

Historically, salicin has been used in traditional medicine to relieve pain and fever. In the 19th century, it was isolated from willow bark, contributing to the understanding of salicylates. The development of acetylsalicylic acid (aspirin) by Bayer in 1897—stemming from salicylic acid chemistry—provided a more tolerable and widely used analgesic, while salicin and related compounds played a key role in the pharmacological lineage leading to modern NSAIDs.

Safety and clinical notes: as with other salicylates, salicin can cause gastrointestinal irritation and other adverse effects. It should be used with caution in individuals with aspirin sensitivity, during pregnancy, or in children with viral infections, due to concerns about Reye’s syndrome. Contemporary medical use favors aspirin and other NSAIDs, with salicin mainly of historical and pharmacological interest.