RESUMEN
Phosphorylated polysaccharide PLEP-1a, with the PO4³â» content of 6.39%, was prepared from LEP-1a by phosphorylation. IR, (13)C NMR and (31)P NMR results of PLEP-1a showed that the original basic structure of the polysaccharide was not changed, and the -H2PO3 group was linked at C6 of LEP-1a. The results of anti-tumor experiments in vivo showed that 100 mg/kg and 400 mg/kg of LEP-1a could significantly improve the food consumption, body weight, tumor inhibition rate and thymus index of S180 sarcoma mice, and increase the levels of SOD, IL-2 and TNF-α in mice blood serum, indicating that LEP-1a had an excellent anti-tumor activity. Furthermore, PLEP-1a had a significantly enhanced inhibitory effect on S180 sarcoma mice than LEP-1a, suggesting that phosphorylation is an effective way of improving the biological activity of LEP-1a.