关键词: 厚朴皮, 多糖, 提取, 响应面分析, 抗氧化

Abstract: In this study, optimization of polysaccharides extraction from Magnolia offcinalis Rend et Wils by response surface methodology (RSM), based on Box–Behnken design, was employed. The antioxidant activities in vitro of polysaccharides from Magnolia skin were investigated including scavenging effects of superoxide anion radical, DPPH? and ABTS?+, Fe2+ chelating activity, as well as Ferric reducing antioxidant power ( FRAP ). The results indicated that the optimized process of polysaccharides extraction from Magnolia skin was pH 7.3, liquid-solid ratio 32:1, temperature 78℃ and time 139min，and under this condition, the maximum yield, 3.47%, was obtained, which was validated. Polysaccharides from Magnolia skin exhibited powerful antioxidant activities. The five indicators of antioxidant activities in vitro of polysaccharides from Magnolia skin were as follows: The per milligram of superoxide anion radical scavenging action was 18.72 ± 2.12 μmol ascorbic acid equivalent (AAE/mg); per milligram DPPH?, ABTS?+ scavenging activities and FRAP value were 0.59 ± 0.047 μmol TE/mg（Trolox equivalent ，TE）, 0.57 ± 0.038μmol TE/mg、2.19 ± 0.31 μmol TE/mg。The per milligram of Fe2+ chelating activity was 0.38 ± 0.02μmol EE/mg（EDTA-2Na equivalent ，EE）. In summary, the optimized process of polysaccharides extraction from Magnolia skin can guide the production of polysaccharides from Magnolia skin, by which, polysaccharides with potential antioxidant properties were obtained. The present investigation can provide a theoretical basis for the further exploitation of polysaccharides from Magnolia skin.

Key words: Magnolia offcinalis Rend et Wils, Polysaccharides, Extraction , Response surface methodology, Antioxidant