Properties of periodate-oxidised polysaccharides. Part VII. The structure of nitrogen-containing derivatives as deduced from a study of monosaccharide analogues

Abstract

Four types of 3-oxadialdehyde, representative of the potential dialdehyde units present in some different oxypolysaccharides, have been treated with isonicotinoylhydrazine or a thiosemicarbazide under the conditions used in the preparation of the polymeric derivatives. From a 1,6-dialdehyde a bishydrazone is obtained, whilst the corresponding 1,5-dialdehyde combines with only 1 mol. of reagent to form a 3,5-dihydroxymorpholine derivative. The presence of a 4-hydroxymethyl group in either a 1,6- or a 1,5-dialdehyde reduces the activity of one aldehyde function, probably by the formation of a hemiacetal linkage, the remaining aldehyde group being converted into a hydrazone. The structure of the polymeric derivatives is discussed in the light of these findings.