 In suspension-cultured maize cells, dimerisation of ferulic acid esterified to polysaccharides occurs mostly in the protoplasm, but may occur in the cell walls when peroxide levels increase due to pathogenesis.In suspension-cultured wheat cells, only the 8,5'-diferulic acid is formed intraprotoplasmically with the other dimers being formed in the cell wall.Most diferulic acids are not commercially available and must be synthesised in lab.