Structure of xylan from culms of bamboo grass (Sasa senanensis Rehd.)

Abstract

Xylan prepared from culms of kumaizasa (Sasa senanensis Rehd.), a representative species of bamboo grass, was hydrolyzed withβ-xylanase ofStreptomyces olivaceoviridis E-86. Four arabinoxylo-oligosaccharides and two glucuronoxylo-oligosaccharides were isolated from the enzymatic hydrolysate of the xylan by chromatography on a charcoal column, a Dowex 1-x8 column, a Toyo-pearl HW-40S column, and a LiChrospher 100 NH₂ column and on preparative paper chromatography. The results of the structural analyses of the saccharides showed that the isolated oligosaccharides had the structures of 3²-α-l-arabinofuranosyl-xylobiose, 3²-α-l-arabinofuranosyl-xylotriose, 3²-α-[β-d-xylopyranosyl-(1 → 2)-l-arabinofuranosyl]-xylobiose, 3³-α-[β-d-xylopyranosyl-(1 → 2)-l-arabinofuranosyl]-xylotriose, 2³-α-4-O-methyl-d-glucuronosyl-xylotriose, and 2³-α-d-glucuronosyl-xylotriose. From the structural analysis of the oligosaccharides derived from the xylan, kumaizasa xylan was concluded to be a kind of arabinoglucuronoxylan having not only stubs of singlel-arabinose and singled-glucuronic acid but also stubs of disaccharide units such asβ-d-xylopyranosyl-(1 → 2)-l-arabinofuranose.