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 1H and 13C NMR spectroscopy including 2D COSY, TOCSY, 1H, 13C 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: Image: see text]