Isolation, structural characterization, and immunostimulatory activity of a polysaccharide from the stem of Trapa acornis Nakano on RAW264.7 macrophages

Trapa acornis Nakano, also known as “Nan-hu-ling” (NHL), is an important agricultural crop whose fruits are commonly consumed as food, while its stems are usually discarded as agricultural by-products. In the current investigation, a homogeneous polysaccharide (NHLP) with a weight-average molecular weight (Mw) of 62.0 kDa was isolated from the stem of NHL. Monosaccharide composition analysis revealed that NHLP was primarily composed of Gal (24.4%), Glc (18.9%), GalA (16.8%), Xyl (12.1%), and Rha