Structural features of alternative lignin monomers associated with improved digestibility of artificially lignified maize cell walls

•Cell wall lignification limits the digestion of biomass and forage crops.•Lignin bioengineering with alternative monomers can enhance digestibility.•Alternative monomers were screened with a biomimetic cell wall model system.•Ideal monomers have multiple ester-linked o-diol or o-triol phenolic groups.•Ideal monomers block cell wall cross-linking and promote lignin fragmentation.