Purification, structural characterization, and modification of organosolv wheat straw lignin.

Biolignin, a wheat straw lignin produced by acetic acid/formic acid/water hydrolysis, was characterized by (31)P and (13)C-(1)H 2D NMR spectroscopy and by size-exclusion chromatography. Biolignin is a mixture of low molar mass compounds (Mn = 1660 g/mol) made up of S, G, and H units and of coumaric and ferulic acid units. β-5 and β-O-4 interunit linkages are partially acylated in the γ-position by acetate and p-coumarate groups.