Structure characteristics of a water-soluble polysaccharide purified from dragon fruit (Hylocereus undatus) pulp

•The precise structure of a dragon fruit pulp polysaccharide (DFPP) was identified.•DFPP had a molecular weight of 2.2 × 103 kDa.•→4-β-d-GlcpA-1→, →6-β-d-Galp-1→ and →4-α-l-Rhap-1→ constituted the backbone.•α-l-Araf-1→5-α-l-Araf-1→ formed the branch chain.

Dragon fruit is a tropical fruit with good taste. It can bring health benefits to human body. As one of the major bioactive components in this fruit, the polysaccharides might contribute to the health benefits. However, the precise structure information remains unknown. A leading polysaccharide of dragon fruit pulp, DFPP, was purified and identified by NMR and GC–MS. →4-β-d-GlcpA-1→, →6-β-d-Galp-1→ and →4-α-l-Rhap-1→ constituted the backbone and α-l-Araf-1 → 5-α-l-Araf-1→ formed the branch chain. The precise structure was putatively identified as below. The molecular weight was 2.2 × 103 kDa. The structure information of polysaccharides will be helpful to understand this fruit.Figure optionsDownload full-size imageDownload as PowerPoint slide