Vacuum ultraviolet circular dichroism of gellan-family polymer films from water and dimethyl sulfoxide.
The denaturing effect of dimethyl sulfoxide (Me2SO) on the conformation of the gellan-welan-rhamsan family of microbial polysaccharides is directly demonstrated by circular dichroism (CD). The three polysaccharides display strikingly similar CD spectra (140-210 nm) for films cast from Me2SO. The disrupting effect of Me2SO on gellan and welan conformations has previously been reported by others on the basis of light-scattering and viscosity studies. Films cast from aqueous solutions at room temperature show more-intense CD bands, both at 182 nm, as is also observed for aqueous solutions, and in the 150-175 nm region. These features correspond to the ordered helical chains found by X-ray diffraction studies of similarly prepared films.
Arndt
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Department of Chemistry, State University of New York at Binghamton 13902-6016, USA.
Stevens
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D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002942:Circular Dichroism; D003837:Deoxy Sugars / Q000737:chemistry; D017666:Deuterium Oxide / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D008351:Mannans / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D013696:Temperature; D014867:Water
D003837:Deoxy Sugars; D008351:Mannans; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; D014867:Water; C065836:rhamnan; C048288:gellan gum; C068570:welan; D017666:Deuterium Oxide; D004121:Dimethyl Sulfoxide