RESUMO
<p><b>OBJECTIVE</b>To investigated the chemical structures and bioactivity of polysaccharides from Isatidis Radix.</p><p><b>METHOD</b>Polysaccharides were extracted and purified by column chromatograph and their chemical structures were identified by UV, IR, NMR, periodic acid oxadation and Smith degradation method and their stimulation effects to macrophage were evaluated by using MTT method.</p><p><b>RESULT</b>Five polysaccharides, polysaccharide A , B, C, D and E were gotten and their molecular weights were 2 000, 1 757.1, 1 34 2.7, 955.6, 11.7 kDa, respectively. Polysaccharide A was composed of arabinose, polysaccharide E was composed of arabinose and galactose, polysaccharides B, C, D were composed of glucose and 1 --> 2, 1 --> 3, 1 --> 4, 1 --> 6 linkages existed in polysaccharides A-E, of A, B, C, D, E were alpha-configurations. Polysaccharides B, C and D showed better bioactivity than polysaccharides A and E with stimulation index (SI) of 5.31, 4.76, 5.17.</p><p><b>CONCLUSION</b>Five polysaccharides are seperated firstly from Isatidis Radix.</p>