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Structural characterization of a 2-O-acetylglucomannan from Dendrobium officinale stem.

Research paper by Yun-Fen YF Hua, Ming M Zhang, Cheng-Xin CX Fu, Zhang-Hui ZH Chen, Gilbert Yuk Sing GY Chan

Indexed on: 01 Sep '04Published on: 01 Sep '04Published in: Carbohydrate Research



Abstract

A heteropolysaccharide obtained from an aqueous extract of dried stem of Dendrobium officinale Kimura and Migo by anion-exchange chromatography and gel-permeation chromatography, was investigated by chemical techniques and NMR spectroscopy, and is demonstrated to be a 2-O-acetylglucomannan, composed of mannose, glucose, and arabinose in 40.2:8.4:1 molar ratios. It has a backbone of (1-->4)-linked beta-d-mannopyranosyl residues and beta-d-glucopyranosyl residues, with branches at O-6 consisting of terminal and (1-->3)-linked Manp, (1-->3)-linked Glcp, and a small proportion of arabinofuranosyl residues at the terminal position. The acetyl groups are substituted at O-2 of (1-->4)-linked Manp and Glcp. The main repeating unit of the polysaccharides is reported.