STRUCTURAL STUDIES OF ACETAN, AN EXOPOLYSACCHARIDE ELABORATED BY ACETOBACTER-XYLINUM

The exopolysaccharide acetan, elaborated by Acetobacter xylinum, has been investigated. The polysaccharide and a heptasaccharide, obtained on enzymic hydrolysis, corresponding to the repeating unit were characterised by sugar and methylation analysis and by NMR spectroscopy and MS. It is concluded that the polysaccharide is composed of repeating units with the following structure. [GRAPHICS] The polysaccharide further contains approximately two 0-acetyl groups per repeating unit, which have not been assigned, but it appears that they are on primary locations.