Structural elucidation and osteogenic activity of a novel heteropolysaccharide from Alhagi pseudalhagi

Alhagi pseudalhagi , commonly known as camel thorn, is used as an indigenous medicinal plant in China. The present study was designed to elucidate the structure of a novel polysaccharide, APP90-2, isolated from Alhagi pseudalhagi and evaluate its osteogenic activity. A homogeneous polysaccharide (APP90-2) was obtained from A. pseudalhagi via DEAE-52 and Sephacryl S-100 columns, with a molecular weight of 5.9 kDa. Monosaccharide, GC–MS, and NMR analyses showed that APP90-2 consisted of α - l -Rha p -(1→, →3)- α - l -Ara f -(1→, →5)- α - l -Ara f -(1→, →4)- β - d -Xyl p -(1→, α - d -Glc p -(1→, →3,5)- α - l -Ara f -(1→, →4)- β - d -GlcA p -(1→, →4)-3-OAc- α - d -Glc p -(1→, →3)- α - d -Gal p -(1→, →3)- β - d -GalA p -(1→, →4)- α - d -Gal p -(1→, →6)- α - d -Man p -(1→, →4,6)- β - d -Gal p -(1→, and →3,6)- β - d -Glc p -(1→ with relative molar ratios of 4.1:1.8:6.1:6.7:1.7:1.0:1.5:2.7:2.4:1.1:2.3:2.6:1.4:2.0. Morphological analyses revealed that APP90-2 interacted with Congo-red and had an obvious honeycomb structure. Additionally, APP90-2 significantly promoted proliferation, differentiation, and mineralization of MC3T3-E1 cells, indicating that APP90-2 exhibited pronounced osteogenic activity. Therefore, our findings suggest that A. pseudalhagi may be used as an alternative medicine or health supplement for the prevention and treatment of osteoporosis.