不同生长年限铁皮石斛多糖含量与特性分析

采用凝胶渗透色谱方法测定多糖分子质量，柱前衍生化高效液相色谱法测定多糖的单糖组成，研究不同种植年限铁皮石斛多糖结构组成的差异及抗氧化能力。结果表明，5?a生铁皮石斛多糖含量最高，为238.60?mg/g，3?a生次之，为232.74?mg/g；4?a生铁皮石斛主要多糖分子质量高达1?383?kDa，3?a生次之，为1?046?kDa；1?a生铁皮石斛多糖的甘露糖比例最大，3?a生次之；3?a生铁皮石斛多糖的Fe3＋还原能力、羟自由基清除能力和总抗氧化能力最高。综合多糖含量和抗氧化活性测定结果得出，3?a生铁皮石斛品质最佳。

Quantification and Characterization of Polysaccharides from Different Aged Dendrobium officinale Stems

This study quantified and characterized polysaccharides from different aged Dendrobium officinale stems. The molecular weights of polysaccharides were measured by gel permeation chromatography, and their monosaccharide composition was analyzed by pre-column derivatization high performance liquid chromatography (HPLC). In addition, the structural characteristics and antioxidant activity of polysaccharides were investigated. The results showed that the stems of five-year-old D. officinale had the highest polysaccharide content (238.60 mg/g), followed by three-year-old D. officinale (232.74 mg/g). The molecular weight of the primary polysaccharide (1 383 kDa) in four-year-old D. officinale was the highest, followed by that (1 046 kDa) of three-year-old D. officinale. Mannose was the most abundant monosaccharide in one-year-old D. officinale, followed by the three-year-old one. The polysaccharides of three-years-old D. officinale had the strongest Fe3+ reducing power hydroxyl radical scavenging activity and total antioxidant capacity. Based on polysaccharide content and in vitro antioxidant activities, the quality of three-year-old D. officinale was the best.