Comparative structural studies of lignin-carbohydrate complexes from Digitaria decumbens (pangola grass) before and after chlorite delignification

摘要: Abstract Lignin-carbohydrate complexes (LCCs) were extracted with methyl sulphoxide from cellulase-digested stem cell-walls of mature pangola grass. Comparative studies, using gel filtration, g.l.c., and spectroscopy, conducted concurrently on digested which had also been treated sodium chlorite. All the LCCs contained hemicellulose protein low contents hydroxyproline. Gel filtration showed markedly increased polydispersity chlorite-treated residues. Chlorite treatment caused loss arabinose galactose, a concomitant increase in proportion xylose degradable by metaperiodate. The untreated comprised polysaccharide, esterified p -coumaric acid, water-insoluble, lignified “hemicellulose A” component (6% carbohydrate) having xylose-to-arabinose ratio high hexoses. These components liberated alkali, as were, unexpectedly, some free arabinose. Chlorite-treated walls gave ester bonds still present, but acid was degraded to lignin-like products, ”hemicellulose A“ xylan (94% isolated. structural relationship material complex, appeared involve monomer oligomer pentose units, diesterified at least, bridging structures acid. Xylose reducing-units be suggesting esterification C-1 LCC. Thus, chlorite delignification causes significant changes polysaccharides non-carbohydrate cell walls, it is suggested that omitted when situ data plant are being sought.