A new polysaccharide from leaves of Sabia parviflora

A new polysaccharide (SPT1) was isolated from Sabia parviflora Wall. ex Roxb., and the structure was identified by GPC, 1D and 2D NMR spectroscopy, SEM and AFM. The results showed that the average molecular weight (Mn) of SPT1 was 4.057 x 10(3) Da, and it was composed of alpha-glucose with a connection mode of 1 -> 6. The SEM showed that the particle size of SPT1 was 1-200 mu m and there were small gaps between the crystals. SPT1 was mainly spherical aggregates in AFM, each aggregate was 0.550-0.983 mu m long, 1.059-2.275 mu m wide and 208-450 nm high. Furthermore, its liver-protective and PTP1B inhibitory activities were evaluated, and the results showed that SPT1 exhibited moderate effects of liver-protective and PTP1B inhibitory activity. The above results provided experimental evidence for the folk application of S. parviflora in the treatment of hepatitis.