Synthesis and Characterization of Multi-Reducing-End Polysaccharides

Authors:

Zhenghao Zhai‡1, Yang Zhou‡2, Andrew G. Korovich1,3, Brady A. Hall4, Hu Young Yoon1, Yimin Yao1,5, Junchen Zhang6, Michael J. Bortner1,5, Maren Roman1,2, Louis A. Madsen1,3, and Kevin J. Edgar1.2*

Affiliation:

  1. Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, United States
  2. Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA 24061, United States
  3. Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, United States
  4. GlycoMIP, Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, United States
  5. Department of Chemical Engineering and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, United States
  6. Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, United States

Description:

Site-specific modification is a great challenge for polysaccharide scientists. Chemo- and regioselective modification of polysaccharide chains can provide many useful natural-based materials and help us illuminate fundamental structure-property relationships of polysaccharide derivatives. The hemiacetal reducing end of a polysaccharide is in equilibrium with its ring-opened aldehyde form, making it the most uniquely reactive site on the polysaccharide molecule, ideal for regioselective decoration such as imine formation. However, all natural polysaccharides, whether they are branched or not, have only one reducing end per chain, which means that only one aldehyde-reactive substituent can be added. We introduce a new approach to selective functionalization of polysaccharides as an entrée to useful materials, appending multiple reducing ends to each polysaccharide molecule. Herein we reduce the approach to practice using amide formation. Amine groups on monosaccharides such as glucosamine or galactosamine can react with carboxyl groups of polysaccharides, whether natural uronic acids like alginates, or derivatives with carboxyl-containing substituents such as carboxymethyl cellulose (CMC) or carboxymethyl dextran (CMD). Amide formation is assisted using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4 methylmorpholinium chloride (DMTMM). By linking the C2 amines of monosaccharides to polysaccharides in this way, a new class of polysaccharide derivatives possessing many reducing ends can be obtained. We refer to this class of derivatives as multi-reducing end polysaccharides (MREPs). This new family of derivatives creates the potential for designing polysaccharide-based materials with many potential applications, including in hydrogels, block copolymers, pro-drugs, and as reactive intermediates for other derivatives.

Publications:

  • Zhenghao Zhai‡, Yang Zhou‡, Andrew G. Korovich, Brady A. Hall, Hu Young Yoon, Yimin Yao, Junchen Zhang, Michael J. Bortner, Maren Roman, Louis A. Madsen, and Kevin J. Edgar*; Synthesis and Characterization of Multi-Reducing-End Polysaccharides; Biomacromolecules, 2023
  • Tags:

    Aldehydes
    Amides
    Biopolymers
    Carbohydrates
    Nuclear magnetic resonance spectroscopy

    Files:

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