Abstract: Polysaccharides isolated from fresh leaves of Aloe vera L. var. chinensis (Haw.) Berger, unique species in China, were studied. Purified on columns of Sepharose 6B-CL, three constituents, A60, A90a and A90b were got. The M. W. of three polysaccharides were calculated to be approximately 12,000, 47,000 and 12,000 respectively by authentic dextrans. A60 contained mannose only and A90b contained glucose and mannose in the ratio of 3:4. Smith degradation indicated acetyl butantetraol, 2,6-dimethylacetyl mannitol, 3,6-dimethylacetyl mannitol and 2,3-dimethylacetyl mannitol for A60 and acetyl butantetraol only for A90b. Methylation analysis of As0 furnished 2,3,6-trimethyl mannose only and methylation analysis of A90b furnished 2,3,6- tri- 2, 3, 4, 6-tetramethylglueose and 2,3,6-trimethylmannose. Both A60 and A90b were shown β-linkage in IR. From these results structure for A60 has been assigned β-(1→4) linked mannan with partially acetylated in 2,3, or 6 and for A90b, β-(1→4) linked glucomannan. Activity against implanted S-180 in mice could not be found in A60. But A60 was able to promote immunity then could be used for treating the hypoimunity diseases.

Key words: Aloe vera, Polysaccharide, Promote immunity