Glucose Scavenging with Pectin Hydrazide: A Step toward Designing Innovative, Functional, All‐Sugar‐Based Polymers

Abstract

Polygalacturonic acid hydrazide (PGH) is one of only a few polysaccharide derivatives with pronounced nucleophilic characteristics known today. This water-soluble and benign material could be reacted with the hydrophilic aldehydes D-glucose in water, without any catalyst and at room temperature, resulting in a product that is the first example of new family of all-sugar-based polysaccharide derivatives. The reaction is reversible, allowing for D-glucose loading and unloading of the PGH. The D-glucose binds as the 𝜶−, and 𝜷 anomer of the glucopyranosyl form. The reaction is orthogonal to the reactivity of the hydroxyl groups in the polysaccharide and enables the mild generation of new bio-inspired polysaccharide derivatives. The glucose attachment could be rendered irreversibly by reducing the hydrazone with sodium cyanoborohydride, leading to the acyclic sugar derivative. A brief hydrodynamic and light scattering study of the polymers showed varying macromolecular properties at consistent molar mass values of the modified polysaccharide derivatives.

Efficient heterogeneous synthesis of nucleophilic carboxymethyl hydrazides of polysaccharides

“…[ 4 ] The products thus obtained are water soluble, can bind multivalent metal ions, and react with aldehydes like glucose or nonanal. [ 5,6 ] PHs have also been shown to generate hydrogels capable of drug incorporation and release, making them interesting for drug delivery studies in anticancer treatment, for example, Zhou et al [ 7 ] Recently, PSs carbazates are gaining attention. [ 8,9 ] These nucleophilic polymers can be obtained by a hydrazinolysis of PS phenyl carbonates.…”