O-Succinyl derivative of ι-carrageenan fragments: Synthesis and characterization

ι-Carrageenan was depolymerized in mild hydrochloric acid condition. Tetrabutylammonium (TBA) salt of ι-carrageenan fragments was acylated with succinic anhydride, 4-dimethylaminopyridine and tributylamine under homogeneous conditions in N,N-dimethylformamide at 80 °C. Investigation of FT-IR spectrum of the succinylated product showed that a monoester derivative with succinyl group was formed when ι-carrageenan reacted with succinic anhydride. The 1H and 13C NMR spectroscopy has been used to characterize the fine structure of O-succinyl derivative of the ι-carrageenan. The 13C and 1H NMR chemical shifts of disaccharide unit of O-succinyl ι-carrageenan have been fully assigned using 2D NMR spectroscopic techniques.