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 ligni fication were characterized by thioacidolysis. The linkage-type analys is by thioacidolysis indicates that the structure of these polylignols approximated that of native lignin more closely than did the structur e of polylignols prepared by the conventional method from coniferyl al cohol. Among various possible factors affecting the structure of polyl ignols during polymerization under the present experimental conditions , the important ones appears to be: pH of the medium in which dehydrog enative polymerization of coniferyl alcohol takes place; relative conc entrations of monomer and oligomer radicals; and the carbohydrate matr ix in which polymerization occurs.