Scheme 1: a) Chemical preparation to produce substituted para-or meta-methoxystyrenes 2e-h as protected biobased monomers of methoxy polystyrenes; b) One-pot two-step reaction sequence for the decarboxylation of phenolic acids (1a-d) by phenolic acid decarboxylase from Bacillus subtilis (BsPAD) and methylation of intermediate hydroxystyrene derivatives (2a-d) catalyzed by resveratrol O-methyltransferase from Vitis vinifera (VvROMT). S-Adenosyl-L-methionine (SAM) is provided as a methyl donor and SAH (S-adenosyl-L-homocysteine) is produced after the donation of the methyl group.