Xyloglucan andrβ-D-Glucan in Cell Walls of Rice Seedlings

摘要

Cell walls of 4-day old rice seedlings were extracted successively with ammonium oxalate-oxalic acid, 4%KOH and 24%KOH. Arβ-D-glucan preparation and a xyloglucan preparation were isolated from the 4%KOH extract and 24%KOH extract, respectively. Methylation analysis and enzymic degradation studies of the polysaccharides showed that the former was built up predominantly of repeating-oligosaccharide units of 3-O-rβ-cellobiosyl-D-glucose and 3-O-rβ-cellotriosyl-D-glucose in a molar ratio of 2.6 : 1.0, and the latter was of repeating-oligosaccharide units ofα-D-xylosyl-(1→6)-rβ-D-glucosyl-(1→4)-[α-D-xylosyl-(1→6)]-rβ-D-glucosyl-(1→4)-D-glucose,α-D-xylosyl-(1→6)-rβ-D-glucosyl-(1→4)-D-gl