Hierarchically controlled assemblies from amylose analog aminopolysaccharides by reductive amination: From nano‐ to macrostructures

Abstract

ABSTRACTIn this study, we found that hierarchically controlled assemblies from amylose analog aminopolysaccharides occurred by reductive amination to obtain nanoparticles, microaggregates, and macrohydrogels depending on reaction conditions. The polysaccharide substrate composed of α(1→4)‐linked glucosamine residues was synthesized by thermostable phosphorylase (from Aquifex aeolicus VF5)–catalyzed enzymatic polymerization of α‐d‐glucosamine 1‐phosphate according to the reaction manner reported in our previous study. The reductive amination of the produced polysaccharide was carried out in the presence of NaBH3CN as reductant in 0.1 mol/L acetic acid aq. at 60 °C for 1 h. When lower feed ratios of reductant to the reducing end of the substrate were employed for the reaction, nanoparticles were obtained. With increasing feed ratios of reductant, more α(1→4)‐GlcNn molecules assembled to further form water‐insoluble microaggregates and macrohydrogels. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45890.