不同提取方法对兰州百合多糖结构及抗氧化活性的影响

Effects of Different Extraction Methods on the Composition and Antioxidant Activity of the Polysaccharides in Lilium davidii var. unicolor Salisb.

摘要:

以兰州百合为原料，研究微波辅助、超声波辅助及超声波复合酶法三种不同提取工艺对百合多糖结构组成的影响，并对其抗氧化活性进行了比较分析。通过微波辅助、超声波辅助及超声波复合酶法分别从兰州百合鳞茎中提取多糖(LPS)，经醇沉、脱蛋白、冷冻干燥后得到3种百合多糖为LPS-M、LPS-C和LPS-CE。红外光谱分析结果表明，LPS-M、LPS-C、LPS-CE在3378 cm-1、2931 cm-1、1640 cm-1、1060 cm-1都有吸收峰，此为多糖的典型红外光谱特征吸收峰；通过GC-MS测定单糖组成分析表明3种多糖的单糖组成类型成分相同，主要由甘露糖、葡萄糖组成，但单糖的摩尔比有所不同，分别为5.2:4.9、5.1:4.7和4.8:5.3。通过清除羟自由基、超氧自由基、DPPH自由基及还原力测定试验表明，3种多糖具有不同程度的抗氧化活性，LPS-CE的体外抗氧化活性要显著高于LPS-C、LPS-M。因此，可将超声波复合酶法作为提取功能性兰州百合多糖的首选方法。

Abstract:

Lilium davidii var. unicolor Salisb. was used as the raw material for the investigation on the effects of three extraction methods, microwave-assisted extraction, ultrasonic-assisted extraction, and ultrasonic treatment coupled with enzymatic hydrolysis, on the structure and composition of the obtained polysaccharides (named LPS-M, LPS-C, and LPS-CE, respectively). After precipitation with ethanol, deproteinization and freeze-drying, the three types of polysaccharide samples were characterized by FT- IR, and the result indicated that LPS-M, LPS-C and LPS-CE all had the characteristic absorption peaks of polysaccharides (at 3378, 2931, 1640 and 1060 cm-1). The monosaccharide compositions of LPS-M, LPS-C and LPS-CE were analysed by GC-MS，and the results showed that these polysaccharides had the same types of monosaccharides but at different molar ratios i.e. the molar ratios of the two major components, mannose and glucose, were at 5.2:4.9, 5.1:4.7, and 4.8:5.3, respectively. The analyses of the antioxidant activities by hydroxyl radicals, superoxide radicals, DPPH free radicals and reducing power assays revealed that antioxidant activity of LPS-CE was significantly higher than those of LPS-C and LPS-M. The method of ultrasonic treatment coupled with enzymatic hydrolysis could be used as the preferred extraction method for extracting functional polysaccharides from Lilium davidii var. unicolor Salisb..