Structure design of multifunctional furoate and pyroglutamate esters of dextran by polymer-analogous reactions

Well-defined multifunctionalized dextran esters bearing photo-crosslinkable and chiral groups as well as small alkyl moieties for the adjustment of the solubility were prepared from two dextran samples with different origin and molecular weight. The examination of side structures of the starting dextran was carried out by different one- and two-dimensional NMR techniques. The main synthesis path via in situ activation of furan-2-carboxylic- and pyroglutamic acid with CDI under mild conditions gives highly functionalized dextran derivatives possessing a degree of polymerization in the range of the starting polysaccharide. The subsequent reaction with propionic anhydride leads to completely substituted, CHCl(3) soluble derivatives useful for the determination of the particular degree of substitution. By variation of the molar ratios of polymer to reagent with photo-crosslinkable- and chiral moieties during the reaction and even by subsequent peracylation, multifunctional dextran derivatives with adjustable properties like the hydrophilic/hydrophobic balance were obtained that may form biocompatible spherical nanoparticles.