The synthesis of various amylose derivatives selectively modified at C-6 leading to the preparation of 6-amino-6-deoxyamylose (4) was carried out under homogeneous conditions. Amylose was initially halogenated directly at the primary carbon either by using methanesulfonyl chloride in dimethylformamide/ lithium chloride as solvent, giving 6-chloro-6-deoxyamylose (1) or with triphenylphosphine and Nbromosuccinimide in dimethylformamide/lithium bromide, giving 6-bromo-6-deoxyamylose (2). Several of these derivatives with different degrees of substitution were prepared. C-6 chlorinated amyloses were then converted to the corresponding 6-azido-6-deoxyamylose analogs (3) by chloride displacement with azide ion in dipolar aprotic media. Triphenylphosphine facilitated reduction of these intermediates in dimethyl sulfoxide gave 6-amino-6-deoxyamyloses with the same degrees of substitution as the C-6 chlorinated precursors. Products were characterized in terms of the site and the extent of modifications using 13C NMR, FTIR, HPLC, and elemental analyses.

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The optimal production of the fructan biopolymer levan by the bacterium Erwinia herbicola was investigated, including variations in nitrogen, carbon and phosphorous sources, pH, incubation time, culture yields up to 19% by weight produced based on conversion of sucrose as the carbon source when grown in a continuous culture system and processed by tangential flow filtration. Product identity was confirmed with gas chromatography (GC) and (13)C nuclear magnetic resonance (NMR). Gel permeation chromatography (GPC) and low-angle laser light scattering (LALLS) determination of the molecular weight of the product showed a significant difference in molecular weight values dependent on the method of analysis. Analysis by GPC resulted in molecular weight one order of magnitude lower than LALLS independent of sample, underscoring the unusual nature of this biopolymer.

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