Tritordeum, a hybrid cereal with a highly tricin-enriched lignin

The lignin from tritordeum straw, a hybrid cereal from crossbreeding of durum wheat and wild barley, was isolated and chemically characterized. Its composition and structure were studied by analytical pyrolysis (Py-GC/ MS), nuclear magnetic resonance spectroscopy (NMR), Derivatization Followed by Reductive Cleavage (DFRC) method, and gel permeation chromatography (GPC). The data revealed an enrichment of guaiacyl (G) units (H:G: S of 3:61:36), which had a significant impact on the distribution of inter -unit linkages. The predominant linkages were the beta-O-4 ' alkyl -aryl ethers (78 % of all linkages), with substantial proportions of condensed linkages such as phenylcoumarans (11 %), resinols (4 %), spirodienones (4 %), and dibenzodioxocins (2 %). Moreover, DFRC revealed that tridordeum straw lignin was partly acylated at the gamma-OH with both acetates and p-coumarates. Acetates were principally attached to G -units, whereas p-coumarates were predominantly attached to S -units. Furthermore, and more importantly, tritordeum lignin incorporates remarkable amounts of a valuable flavone, tricin, exceeding 30 g per kilogram of straw. Given the diverse industrial applications associated with this highvalue molecule, tritordeum straw emerges as a promising and sustainable resource for its extraction.