Spectroscopy polysaccharides

Rief, M., Oeslerhelt, F., Heymann, B. and Gaub, H.E., Single molecule force spectroscopy on polysaccharides by atomic force microscopy. Science, 275(5304), 1295-1297 (1997). 

The Structure of a Polysaccharide Synthesized by a Streptococcus Isolated from a Ropy Fermentation, The Value of Infrared Spectroscopy in Polysaccharide Studies, S. A. Barker, F. Pautard, I. R. Siddiqui, and M. Stacey, Chem. Ind. (London), (1955) 1450-1451. 

Extensive studies have been performed on the (1- 6)-)8-D-glucan (pustulan) and the (l- 4)-a-D-glucan (amylose). These are linear polysaccharides that may exist as helical polymers in aqueous solution, as demonstrated by c.d. spectroscopy. Characteristic of the helical structure of these glucans is a negative band at 182 nm, a crossover at 177 nm, and a more intensely positive band at shorter wavelengths (see Figs. 8 and 9). 

C.d. spectroscopy is now being applied to more complicated polysaccharides. The 3-deoxy-D-man o-2-octulopyranosylonic acids found in Escherichia coli LP1092 have been definitely assigned the a-D configuration. The negative nir c.d. band exhibited by this polysaccharide correlates with the negative c.d. of methyl 3-deoxy-a-D-wianno-2-octulopyranosidonic acid rather than the positive c.d. band exhibited by methyl 3-deoxy-)3-D-/ a/ino-2-octulopyranosidonic acid. 

E. ten Grotenhuis, M. Paques, G. A. van Aken 2000, (The application of diffus-ing-wave spectroscopy to monitor the phase behavior of emulsion-polysaccharide systems),/. Colloid Interface Sci. 227, 495. 

Like in gangliosides, lactones might be found in some bacterial capsular polysaccharides containing 1-carboxyethylsubstituents. But their identification remains problematic due to the conditions of isolation and preparation of analytic samples. To facilitate their detection by NMR, and in order to determine if the formation or hydrolysis of lactones occurred during analytical procedures, synthetic model substances, 2,3- and/or 3,4-lactones based on gluco-12, manno-13, and galactopyranosides 14 were prepared and characterized by NMR spectroscopy (Fig. 2).20 The relative lactonisation rates in acetic acid-fi 4 and hydrolysis rates in buffered D20 were evaluated. 

CARBON-13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY OF POLYSACCHARIDES... 

The advent of studies of polysaccharides by carbon-13 nuclear magnetic resonance (13C-n.m.r.) spectroscopy coincided, not surprisingly,... 

C-n.m.r. spectroscopy is useful in monitoring the purity of polysaccharide preparations. Similarly, in a multicomponent, biological system, such as exists in fungal cell-walls, the varying proportion of each polysaccharide can be gauged, once characteristic signals have been identified. 

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