Reducing-End Functionalization of 2,5-Anhydro-<span style="font-variant: small-caps">d</span>-mannofuranose-Linked Chitooligosaccharides by Dioxyamine: Synthesis and Characterization

Abstract

The nitrous acid depolymerization of chitosan enables the synthesis of singular chitosan oligosaccharides (COS) since their reducing-end unit is composed of 2,5-anhydro-d-mannofuranose (amf). In the present study, we describe a chemical method for the reducing-end conjugation of COS-amf by the commercially available dioxyamine O,O′-1,3-propanediylbishydroxylamine in high mass yields. The chemical structure of resulting dioxyamine-linked COS-amf synthesized by both oximation and reductive amination ways were fully characterized by 1H- and 13C-NMR spectroscopies and MALDI-TOF mass spectrometry. The coupling of chemically attractive linkers such as dioxyamines at the reducing end of COS-amf forms a relevant strategy for the development of advanced functional COS-based conjugates.

Keywords

• chitosan
• oligomer
• reducing-end
• conjugation
• building-block
• oxyamine