The monolignols are derived from the amino acid phenylalanine via the phenylpropanoid pathway involving various enzymes. Phenylalanine is first converted to paracoumaryl alcohol (H), which is subsequently elaborated to coniferyl alcohol (G) and sinapyl alcohol (S). This reaction happens in the  cytosol, while the polymerization of the monolignols occurs in the apoplast to which the monolignols have to be transported to though the cell membrane.
The monolignols are derived from phenylalanine via the phenylpropanoid pathway, involving various enzymes. Phenylalanine is first converted to paracoumaryl alcohol (H), which is then elaborated to coniferyl alcohol (G) and sinapyl alcohol (S). This process occurs in the cytosol, while the polymerization of monolignols takes place in the apoplast, requiring transport through the cell membrane.