从兽疫链球菌C55129菌株发酵液中提取到荚膜多糖粗品(CCP),通过DEAE-52纤维素阴离子交换柱和Sephadex G-100凝胶柱层析,从CCP中分离到中性糖组分PCP-I,得率为5.989%,分子质量为0.029 2×103k Da。气相色谱法结果表明PCP-I单糖组成及摩尔比为阿拉伯糖∶甘露糖∶葡萄糖∶半乳糖=0.99∶27.03∶11.84∶1.00。体外抗氧化实验结果显示,PCP-I有较强的螯合金属离子能力、还原力和抑制脂质过氧化作用,适度的清除DPPH·、超氧阴离子自由基(O-2·)和羟自由基(·OH)活性的能力。

Crude capsule polysaccharides( CCP) from S. zooepidemicus C55129 were separated by ethanol precipitation. CCP were separated and sequentially purified through a column of DEAE-cellulose 52 and a column of sephadex G-100 to afford purified fraction of capsule polysaccharide( PCP-I) with molecular weight of about 0. 0292 ×103k Da. The recovery rate of PCP-I was 5. 989 %. Monosaccharide composition and molar ratio of PCP-I were analyzed by Gas chromatography( GC). Results showed that arabinose ∶ mannose ∶ glucose ∶ galactose was 0. 99 ∶ 27. 03 ∶11. 84∶ 1. 00. In vitro antioxidant assay,PCP-I not only showed strong chelating ability for metal ions and inhibition of lipid peroxidation and reducing power,but also can moderately scavenge the activities of 1,1-diphenyl-2-picryldydrazyl radical,superoxide radical,and hydroxyl radical.