小分子Rhizobium sp. N613胞外多糖的制备及其抗肿瘤活性

采用微波辐照氧化技术,降解大分子Rhizobium sp.N613胞外多糖(REPS)为小分子多糖(LREPS),以改善其理化及抗肿瘤活性,提高应用价值和拓展应用范围。通过正交试验考察了底物浓度、H2O2浓度、微波辐照强度和辐照时间对降解产物分子量的影响并获得一系列LREPS产物。选取4组分子量段(10以下、10、20和30 kD左右)的LREPS代表性样品进行小鼠体内S180抑瘤效果检测,其中分子量段为10.352 kD的LREPS效果最佳,抑瘤率高达52.8%,确定为LREPS的最适分子量段。其制备工艺条件为:REPS浓度为2 g/L、H2O2浓度为6%、微波辐照强度为375 W、微波辐照时间为2 min;理化分析结果表明,LREPS的红外图谱与REPS相似,仍为β-D-吡喃葡聚糖。其溶解度由原多糖的8.00 g/L增至15.73 g/L,特性粘数由原多糖的527.64 mL/g降至351.67 mL/g。建立了LREPS制备工艺并获取了相关理化及抗肿瘤技术参数,为该多糖制剂的生产应用奠定一定基础。

Preparation and anti-tumor activity of low molecular weight exopolysaccharide from Rhizobium sp. N613

Exopolysaccharide from Rhizobium sp.N613(REPS) was degraded by microwave irradiation with H2O2 to improve its physical,chemical and anti-tumor activity.Effects of REPS's concentration,H2O2's concentration,intensity and time of microwave irradiation on the molecular weight of degradated products were investigated by orthogonal test.Then the antitumor activities of four different molecular weight of LREPS were evaluated in mice bearing sarcoma 180.The results indicated that inhibition rate reached 52.8% when ...