Structure characterization of high molecular weight heteropolysaccharide isolated from Artemisia sphaerocephala Krasch seed

► Structural properties of ASK polysaccharide was investigated. ► Methylation analysis and 1D & 2D NMR spectroscopy were used. ► This polysaccharide was proved to be arabinoxylan with T-GlcpA attached. ► A possible structure was proposed in this manuscript.