Imidazoles from the reaction of periodate-oxidized polysaccharides with ammonia

Abstract

Periodate-oxidized amylose reacts with aqueous ammonia to give imidazole and 4(5)-(2-hydroxyethyl)imidazole while periodate-oxidized dextran gives imidazole and 4(5)-methylimidazole. Laminarin after periodate oxidation gives only traces of imidazoles with ammonia. A mechanism is proposed for the formation of these imidazoles from periodate-oxidized polysaccharides. The nature of the imidazoles formed is specific to the linkage in the parent polysaccharide and hence provides a basis for a micro method for linkage analysis.