Pathway of Coumarin metabolism by enzyme extracts of Pseudomonas melilotica.

Coumarin (2-oxo-1,2-benzopynpl), a lactone of o-hydroxy-dis-cinnamic acid is a naturally occurring constituent of certain plants, especially sweet clover. Coumarin, present in "spoilt" clover, is sometimes ingested by livestock causing a haemorrhagic condition. Stahmann et al. (1941) identified dicoumarol as the active principle involved. Due to the strong structural relationship of dicoumarol with coumarin, Robert and Link (1937) believed that dicoumarol was formed from coumarin. Many of the coumarin derivatives are pharmacologically active and include anticoagulant drugs, rodenticides and insecticides. Due to its bitter taste and vanilla-like odour, coumarin itself has been employed for flavouring foods but its use has been discouraged owing to its damaging effect on the liver of animals