PHENOLICS
Phenylpropanoid metabolism begins with the precursors phenyalanine and/or tyrosine produced by the shikimic acid pathway. The enzyme PAL (phenylalanine (tyrosine) ammonia-lyase) converts phenylalanine to cinnamic acid and tyrosine to p-coumaric acid. Aromatic hydroxylations, O-methylations, CoA ligations and NADPH-dependent reductions are the four types of enzymatic reactions that occur throughout this pathway. Phenylpropanoid metabolism may lead to several families of phenols, such as flavenoids, stilbenes, styrylpyrones and coumarins as well as the precursors for lignin and lignan synthesis.
