Chemical structure of aeromonas gum -: extracellular polysaccharide from Aeromonas nichidenii 5797

Aeromonas (A) gum, an extracellular heteropolysaccharide produced by the bacterium Aeromonas nichidenii strain 5797, was studied by H-1 and C-13 NMR spectroscopy including 2D COSY, TOCSY, H-1, C-13 HMQC, HMBC and ROESY experiments after O-deacetylation and Smith degradation. These investigations revealed the presence of an O-acetylated pentasaccharide repeating unit composed of mannose, glucose, xylose and glucuronic acid, and it has the following structure: [GRAPHICS] (C) 2004 Elsevier Ltd. All rights reserved.