Abstract
Coumarins, a group of naturally occurring phenylpropanoid lactones exerting a wide
range of physiological effects, are elaborated by many plants and in a few microbial
species. Early studies on the biosynthetic reactions leading to the simple coumarins
in plants demonstrated derivation from the shikimic acid pathway via cinnamic acid
and either ortho– or para–hydroxycinnamic acid. Radiotracer experiments later indicated that the furan ring
of the furanocoumarins, found chiefly in the Rutaceae and Umbelliferae, is constructed
on the coumarin nucleus following attachment of a mevalonate–derived side–chain to
umbelliferone, and cyclization to dihydrofuranocoumarin intermediates. These findings
have been substantiated and extended by the isolation and characterization of several
of the enzymes participating in the biosynthetic pathway.
Key Word Index
Biosynthesis - Coumarins - Furocoumarins
