text: The furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. Most of the plant species found to contain furanocoumarins belong to a handful of plant families. The families Apiaceae and Rutaceae include the largest numbers of plant species that contain furanocoumarins. The families Moraceae and Fabaceae include a few widely distributed plant species that contain furanocoumarins.
  Generally furanocoumarins are most abundant in plants that have flowered and in ripe seeds and fruits. (An exception is the common fig where furanocoumarins are found chiefly in the milky sap of the leaves and shoots but not the fruits.) During the early stages of plant growth, their presence is not easily detected.
  Structure
  The chemical structure of furanocoumarins consists of a furan ring fused with a coumarin. The furan ring may be fused in various ways producing several different isomers.  The parent compounds of the most common isomers are psoralen and angelicin. Derivatives of these two compounds are referred to respectively as linear and angular furanocoumarins, so called since they exhibit a linear or angular chemical structure.
  Biosynthesis
  The compounds are biosynthesized partly through the phenylpropanoid pathway and the mevalonate pathway, which is biosynthesized by a coupling of dimethylallyl pyrophosphate (DMAPP) and 7-hydroxycoumarin (umbelliferone).
  Effects