Location of O-acetyl groups in S-657 using the reductive-cleavage method

• Published in: Carbohydrate research Vol. 331; no. 3; pp. 265 - 270
• Main Authors: Diltz, Sandra, Zeller, Samuel G.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 12.04.2001
• Subjects: Acetylation; Carbohydrate Conformation; Carbohydrate Sequence; Chromatography, Gas; Hydrolysis; Methods; Methylation; Molecular Sequence Data; Molecular Structure; O-Acetyl groups; Oxidation-Reduction; Polysaccharide; Polysaccharides, Bacterial - chemistry; S-657; Sphingomonas - chemistry; Structural analysis; S-657; O-Acetyl groups; Polysaccharide; Structural analysis
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/S0008-6215(01)00045-3

A two-step procedure is described in this paper to identify the position of O-acetyl groups in S-657 polysaccharide. Reductive-cleavage experiments performed on the fully methylated (base-catalyzed) polysaccharide, followed by acetylation of anhydroalditols, identified individual sugar residues and their position of linkage. In a second experiment, the polysaccharide was methylated under neutral conditions leaving native acetate groups intact. Reductive cleavage of the neutral methylated polysaccharide using CF 3SO 3SiMe 3 as a catalyst, followed by acetylation in situ, identified sugar residues containing native acetate groups and established their position of substitution. Using this two-step procedure of analysis, S-657 polysaccharide is shown to contain O-acetyl groups on the 2-position and the 2,6-positions of 3-linked glucopyranosyl residues.