Synthesis and preliminary characterisation of charged derivatives and hydrogels from scleroglucan

Carbohydr Res. 2000 Feb 11;324(2):116-26. doi: 10.1016/s0008-6215(99)00286-4.

Abstract

The synthesis of negatively and positively charged polyelectrolytes from scleroglucan is described. Polycarboxylates were synthesised through nucleophilic substitution with chloroacetic acid or through a selective 2,2,6,6-tetramethyl-l-piperidinyloxy (TEMPO)-mediated oxidation of the primary alcohol groups. Amine groups were introduced through nucleophilic substitution with 2-chloroethylamine or 3-chloropropylamine. Reaction conditions were varied to obtain insight into the influence of variables on the degree of substitution. The conformational behaviour of the obtained polyelectrolytes was studied as a function of pH, temperature and solvent. For the products with a low degree of modification, evidence of an ordered conformation was found, whereas the polymers with a higher degree of modification behaved as random coils in solution. The negatively charged polymers were reticulated using the Ugi four-component condensation, obtaining negatively charged hydrogels. The positively charged polymers were reticulated using diethyl squarate (3,4-diethoxy-3-cyclobutene-1,2-dion, DES) to obtain positively charged hydrogels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Acetates
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Cross-Linking Reagents
  • Cyclic N-Oxides
  • Electrolytes / chemical synthesis
  • Electrolytes / chemistry
  • Glucans / chemistry*
  • Hydrogels / chemical synthesis*
  • Hydrogels / chemistry
  • Hydrogels / isolation & purification
  • Hydrogen-Ion Concentration
  • Methylation
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Solvents
  • Static Electricity
  • Temperature

Substances

  • Acetates
  • Cross-Linking Reagents
  • Cyclic N-Oxides
  • Electrolytes
  • Glucans
  • Hydrogels
  • Solvents
  • scleroglucan
  • chloroacetic acid
  • TEMPO