Structure of the polysaccharide Zanflo elaborated by Erwinia tahitica ATCC 217 11

✍ Scribed by Anders Johansson; Per-Erik Jansson; Göran Widmalm

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 385 KB
• Volume: 264
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(94)00184-7

✦ Synopsis

The polysaccharide Zanflo from Erwiniu tahitica ATCC 217 11 (S-10) [ 1] is one of many being prepared for industrial applications. It is valuable because of its fermentation efficiency and product properties. These include better viscosity than xanthan gum and larger compatibility with dyes. We have now elucidated the structure of the carbohydrate backbone of Zanflo, using NMR studies, methylation analysis, partial acid hydrolysis, and uranic acid degradation.

Previous analysis of Zanflo showed glucose, galactose, glucuronic acid, fucose, and Oacyl groups as components [ 11. A hydrolysate using hydrolysis with 2 M CF,CO,H gave fucose, glucose, and galactose in the proportions 27:42:31 (Table 1, column A). GLC analysis of a sample that had been treated with methanolic hydrogen chloride also showed glucuronic acid. The absolute configurations of the sugars were determined according to Gerwig et al.

[2] on a premethanolysed sample of S-10 and showed L-fucose, D-glucose, D-galactose, and D-glUCUrOniC acid. Methylation analysis showed the presence of terminal D-galactose, 4-substituted L-fucose, and 3,4-substituted D-glucose (Table 2, column A) _ When the native polysaccharide was methylated and then carboxyl-reduced, an additional 4-substituted D-glucuronic acid was demonstrated (Table 2, column B) . From these data, a repeating unit of four sugar residues is indicated.

lH NMR spectra of native Zanflo (Fig. 1) showed, inter aliu, the presence of the methyl group of a 6-deoxyhexose and a complex anomeric region. The reason for this complexity * Corresponding author.