Abstract: The preparation of acetylation derivatives of Acanthopanax obouatus Hoo polysaccharides was studied.The influences of reaction time,ratio of polysaccharides-to-acetic anhydride and reaction temperature on the degree of substitution (DS) were studied by response surface methodology (RSM).The optimal conditions were reaction time of 3.0 h,ratio of polysaccharides-to-acetic anhydride of 3.7 and reaction temperature of 70 ℃.Compared with A.obouatus polysaccharides,the antioxidant ability of acetylation derivatives was improved.

Key words: Acanthopanax obouatus Hoo, polysaccharides, acetylation, response surface methodology, antioxidant ability