杜梨(Pyrus betulifolia Bge.)多糖提取工艺及其清除自由基活性

Extracting Technology and Free Radical Scavenging Activity of Polysaccharide from Pyrus betulifolia Bge.Fruits

通过L9(33)正交试验获得杜梨(Pyrus betulaefolia Bge.)多糖最佳提取工艺。在运用紫外光谱、红外光谱及高效液相色谱等方法研究杜梨多糖(PBP)理化性质的基础上,进一步评价了PBP对羟自由基(.OH)、超氧阴离子自由基(O2-.)和1,1-二苯基-2-苦基肼(DPPH)自由基的清除活性。结果表明,在料液比为1∶15,90℃下提取5h的最优条件下,PBP提取率达到18.65%。多角激光光散射仪分析表明,PBP分子质量为392.9kD。单糖组成分析表明,PBP是由阿拉伯糖、半乳糖醛酸、鼠李糖、半乳糖和葡萄糖组成,摩尔比为49.54∶28.68∶8.81∶8.45∶4.54。PBP不仅具有清除羟自由基和超氧阴离子自由基活性,对DPPH自由基的清除活性更强。

The optimum extraction technology of polysaccharides from Pyrus betulaefolia was acquired by L_9(33) orthogonal experiment design method.Physicochemical properties of Pyrus betulaefolia polysaccharide(PBP) were analyzed by ultraviolet spectra,infrared spectroscopy,and high performance liquid chromatography.The scavenging activities of hydroxyl free radicals,superoxide anion free radicals and DPPH free radicals were further evaluated.The results showed that the best condition was acquired when the ratio of solid to liquid was 1∶15 and extracting at 90 ℃ for 5 hours,and highest extraction yield of PBP was 18.65%.The molecular mass of PBP was 392.9 kD by multi-angle laser light scattering instrument.The monosaccharides of PBP were consisted of arabinose,galacturonic acid,rhamnose,galactose and glucose,with a molar ratio of 49.54∶28.68∶8.81∶8.45∶4.54,respectively.PBP not only showed obvious scavenging effect on hydroxyl and super oxygen-anion free radical,but also showed higher scavenging activity for DPPH free radical.