Design of sulfated benzofurans on the basis of the structure of sulfated lignins, which were found to be potent inhibitors of thrombin. Sulfated lignins are a three-dimensional network of chemo-enzymatically coupled 4-hydroxy cinnamic acid monomers. Four different inter- monomeric linkages are possible in these oligomers including β-5, β-O4, β-β and 5-5 linkages. Chiral centers are identified using curvy bonds. The chain length of sulfated lignins is typically 5–15-monomer units. Sulfated benzofurans studied in this work were designed from one specific structure generated by β-5 linked monomers, as shown by the structure in box. Positions 2, 3, 5 and 6 are numbered. See text for details.