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Keywords Lignin polymer model Dehydrogenation polymer of monolignol (DHP) Coniferin Monolignol glucoside Coniferyl alcohol I3 C NMR SummaryGuaiacyl-type lignin polymer models were prepared from coniferin by the action of ß-glucosidase and peroxidase, with hydrogen peroxide generated in situ through the action of oxygen and glucose oxidase on the glucose liberated from the coniferin. Polylignols were also prepared from coniferyl alcohol using procedures modified to more closely correspond to conditions prevailing in the cell wall environment. The structure of these novel polylignols approximated that of native lignin more closely than did the structure of polylignols prepared by the conventional method from coniferyl alcohol.

Dehydrogenation polymers (DHPs) were prepared from coniferyl alcohol (CA), sinapyl alcohol (SA), and a mixture of coniferyl and sinapyl alcohol. The polymers were fully acetylated and their carbon NMR spectra were compared. Comparison of the 13 C NMR spectra of the DHPs with those of authentic tri-and tetralignols facilitated the assignment of about 85% of the 117 reported signals. Most of the unassigned signals were those from syringyl units. Major differences between the DHP prepared from CA and a pine milled wood lignin were: a relative deficiency of ß-O-4 linkages and a predominance of ß-5, ß-ß, and CA end units in the DHP. In contrast, there was no significant quantity of SA end units in a DHP prepared from SA. A major conclusion of the study confirmed that DHPs prepared from CA are relatively poor models of natural lignins isolated from gymnosperms.