Synthesis and characterization of dextrin monosuccinate

Reaction conditions, including reaction solvents, reaction time, reaction temperature, and molar ratio of succinic anhydride (SA) to anhydroglucose units (AGU) in dextrin, were investigated for preparing dextrin monosuccinate with high degree of substitution (DS). The results showed the optimum conditions as follows: Solvent, dimethyl sulfoxide; reaction temperature, 50 °C; reaction time, 16 h; and molar ratio of SA to AGU in dextrin, 6:1. Under these conditions, the maximum DS reached 2.64. The chemical structure of dextrin monosuccinate was identified using FT-IR and 13C NMR. The FT-IR data indicated the absorption bands of esters and carbonyl acids at 1726 and 1574 cm−1. Signals at 173.13, 171.81, 28.79, and 28.61 ppm in 13C NMR spectrum were ascribed to carbons in ester, carbonyl acid, and methylene. These data suggest that the prepared dextrin succinate was monoester with functional carbonyl acid groups and could be used in polymer therapy as drug carriers.