<Original>Lignin-carbohydrate Complexes from Albizia falcata (L.) Back.

Abstract

Lignin-carbohydrate complexes (LCCs) have been extracted from tropical hard wood of Albizia fakata (L.) Back, by a modified Bjorkman method. After extraction of milled wood lignin (MWL) from the hard wood, LCCs were isolated by successive extraction of the residual wood meal with water (LCC-WE) and 4% NaOH (LCC-AE). NMR and methylation analysis of the LCCs indicated that carbohydrate moiety of LCC-AE was composed of 4-O-methyl-glucuronoxylan while polyose component of LCC-WE consisted of glucomannan and xylan. Analysis of neutral fraction from LCC-WE revealed that this LCC contained β-1,4-linked xylan chain bearing no glucuronic acid residue. In addition, it has been clarified by DDQ-oxidation that the glucuronoxylan was directly bound to the lignin through C-2 and C-3 positions of xylose unit by ether linkage.