Figure 4

Cross-coupling reactions of canonical non-acylated and acylated monolignols (a) and non-canonical hydroxycinnamaldehydes (b) giving rise to the β–O–4 and 8–O–4 linkage units, respectively, in lignin polymers. pCA, p-coumarate. PS, polysaccharides. QM, quinone methide intermediates. LAC, laccase; PRX, peroxidase.