Structure of a water-insoluble d-glucan isolated from a streptococcal organism

✍ Scribed by Satoaki Shibata; Irwin J. Goldstein; Jerome J. Kirkland

• Book ID: 102991036
• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 530 KB
• Volume: 120
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(83)88008-2

✦ Synopsis

The structure of the extracellular polysaccharide (water-insoluble D-ghican) from an anaerobic, Gram-positive coccus organism (Streptococcus) has been investigated. Acid hydrolysis of the methylated glucan yielded 2,3,4,6-tetra-, 2,3.4tri-, 2,4,6-tri, and 2,4-di-O-methyl-D-glucose in the molar ratios of 1.13:3.99: 1.00: 1.02, indicating that the D-glucan has a branched structure containint (1+6)-and (1+3)-a-D-glucosidic bonds with an average repeating unit of seven sugar residues. The D-glucan-polyalcohol, derived by successive periodate oxidation and borohydride reduction, gave, on complete hydrolysis with acid, glycerol and D-glucose (molar ratio, 2.2: 1 .O). Methylation of the D-glucan-polyalcohol yielded, upon hydrolysis, 2,4,6-tri-, and 2,4-di-O-methyl-D-glucose (molar ratio, 1 .O: 1.1). Methylation of the D-glucan-polyalcohol following Smith degradation (mild acid hydrolysis) gave 2,4,6-tri-O-methyl-D-glucose as the principal hydrolysis product, in addition to a trace of 2,3,4,6-tetra-O-methyl-D-glucose. *Dedicated to Professor Elvin A. Kabat.