Abstract: Fucoidan is the primary bio-active component in Hizikia fusiforme, an algae widely distributed in China. DJL is a product of Hizikia fusiforme-originated fucoidan after desulfation and partial hydrolysis. In this study, the structure of DJL was elucidated using 2D NMR spectroscopy and methylation analysis. The result shows that DJL has a molecular weight of 11 KDa and is composed of mannose (Man) and glucouronic acid (GlcA) with a composition ratio of about 1∶1. Its possible structure was also determined to be β-D-GlcA(1→ [2)-α-D-Man(1→4)-β-D-GlcA(1→]_n1→4)-β-D-Gal(1→[4)-β-D-GlcA(1→2)-α-D-Man(1→]_n2→4)-β-D-GlcA(1→2)-α-D-Man.

Key words: NMR, structure, Hizikia fusiforme, fucoidan, polysaccharide