New preparations of lignin polymer models under conditions that approximate cell wall lignification .2. Structural characterization of the models by thioacidolysis

The structures of novel lignin polymer models prepared from coniferin or coniferyl alcohol under conditions that approximate cell wall lignification were characterized by thioacidolysis. The linkage-type analysis by thioacidolysis indicates that the structure of these polylignols approximated that of native lignin more closely than did the structure of polylignols prepared by the conventional method from coniferyl alcohol. Among various possible factors affecting the structure of polylignols during polymerization under the present experimental conditions, the important ones appears to be: pH of the medium in which dehydrogenative polymerization of coniferyl alcohol takes place; relative concentrations of monomer and oligomer radicals; and the carbohydrate matrix in which polymerization occurs.